chapter-2 review of literature -...
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Chapter-2
REVIEW OF LITERATURE
Effluents are wastes produced from industries and they vary depending on the
human activities that produce them. Production of these wastes is an integral part of
industrial activities but unfortunately our inability to anticipate or predict the types
and magnitude of undesired consequences of unbridled release of effluents in our
environment, coupled with the growth of industrialization have resulted in massive
and destructive operations in our ecosystems.
Although industrial processes are desirable, at the same time, the serious and
irreversible damage done to the environment through their apparently innocuous
discharges of effluents are unquantifiable. Until now, effluents are discharged into
rivers, estuaries, lagoons or the sea without treatment by most o industries. However,
despite the treatment being employed by some industries, it is still impossible to
remove all undesirable properties from effluents.
A detailed review of literature was performed to know the work done on
similar or related aspects with respect to industrial effluents. Keeping in view the
objectives of the present investigation, the literature surveyed, been presented in three
following heads.
I. Constituents of different types of industrial effluents
II. Effects of industrial effluent on growth, yield and phenology of different
plant species
III. Acquired toxicity in selected plant species through different industrial
effluents
2.1. Constituents of different industrial effluents
Industrial effluents carry with them some substances that are usually not found
in water streams. For example vegetable oil industries release unused oil/ fatty acid
which form emulsion when mixed with water. This emulsified water is used to irrigate
crops or plants in surrounding areas. During absorption of such polluted
water/emulsified water xylem vessels are chocked and normal plant growth is affected
which can easily be seen in industrial belts. When such industrial effluents are
frequently used for irrigation it causes plant mortality as some of the crops/plant
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species are more sensitive to the contaminated water as compared to others. The
effluents from vegetable oil industries and refineries are known to contain nickel,
dissolved solid, suspended solids material etc. Similarly, the effluents from steel
industries are known to release heavy metals. The other industries like, tanneries
require huge quantity of water for different tanning processes, which ultimately comes
out as wastewater, and technically known as tannery effluent. A number of chemicals
like common salt, lime, sodium sulphide, ammonium sodium carbonate, dye,
sulphonated vegetable oils, vegetable tanning materials basic chrome etc. are used in
different tanning operations, thus tannery effluent has much pollution load and
adversely affect the water stream, land/soil or ground water quality when ever
disposed off partially treated or untreated (Burfal et al., 1999). In following pages,
review has been presented on constituents of effluents released by different types of
industries from different parts of world.
2.1.1. Vegetable Oil and Food Processing Industry
Erickson (1998) compared the wastewater loads from major sources following
fat-trapping and found that in acidic water the total fatty content ranged from 500-
1000 mg/L, COD was expressed to be 2000-8000 mg/L, sulphate content ranged from
3500 to 20000 mg/L. The total fatty substance ranged from 20-10000 mg/L and COD
from 40 to 14000 mg/L. There was no sulphate content and the pH of the water
ranged from 6.5 to 8.0.
As per the Pollution Prevention and Abatement Handbook of World Bank
(1998) the wastewater from vegetable oil processing industry is high in organic
content, resulting in a biochemical oxygen demand (BOD) of 20,000–35,000
milligrams per liter (mg/l) and a chemical oxygen demand (COD) of 30,000–60,000
mg/l. In addition, the wastewaters contains high amount of dissolved solids (10,000
mg/l), oil and fat residues (5,000–10,000 mg/l), organic nitrogen (500–800 mg/l), and
ash residues (4,000 to 5,000 mg/l). Seed dressing and edible fat and oil processing
generate approximately 10–25 m3 of wastewater per metric ton (t) of product. Most of
the solid wastes (0.7–0.8 t/t of raw material), which are mainly of vegetable origin,
can be processed into by-products or used as fuel.
Ikhu-Omoregbe et al. (2001) characterized effluent discharges from edible oil
producing industries in Bulawayo, Zimbabwe. Snap and composite samples of the
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liquid effluents were collected manually from manholes and discharge outlets of the
two edible oil producing plants for a period of six months. Samples were analyzed
using standard procedures. The effluent did not meet the regulatory quality standards
established by the municipality. The effluent was characterized by high values of
soap, oil and grease (SOG), chemical oxygen demand (COD), sulphates, total
dissolved salts and turgidity.
In a comparative evaluation of a laboratory and full-scale treatment
alternatives for the vegetable oil refining industry wastewater (VORW), Azbar and
Yonar (2003) analyzed the effluent in terms of pH (6.3–7.2), biochemical oxygen
demand (BOD) (4300–4700 mg l−1
), oil and grease (3600–3900 mg l−1
), total
suspended solids (TSS) (3800–4130 mg l−1
), total Kjeldahl nitrogen (TKN) (636–738
mg l−1
) and total phosphorus (TP) (61–63 mg l−1
). Vegetable oil wastes are made of
plant residues and oils. These discarded wastes pose a significant disposal problem in
many parts of the world. Several plants provide oil to fulfill nutritional needs (olive,
palm, soybean, rapeseed, sunflower and peanut). But some of the plants like olive oil
extraction plant produce a large quantity of wastes as residues. Such wastes are
characterized by low pH values, high contents in phenols and their derivates, organic
matter and nutrients. Hence, proper treatments of such waste are required to limit their
impact on the environment. The use of microbial communities for the degradation
(aerobic or anaerobic) of organic matter is one of the most frequently used methods.
However, due to the high content of useful substances, vegetable oil wastes have to be
considered as a resource for agriculture, food, pharmaceutical, and oleo-chemistry
industries (Denaro et al., 2010).
Tariq et al. (2006) reported that the effluents of a vegetable oil (ghee) factory
in Peshawar had a temperature of 33.9oC, pH 7.80, EC 288, TSS 426 mg/L, TDS 288
mg/L and BOD 110 mg/L. The heavy metal content for Cd, Cr, Cu, Fe, Mn, Ni, Pb
and Zn were 0.02, 0.30, 0.39, 0.46, 0.02, 0.88, 0.43 and 0.01 mg/L, respectively.
World Bank Group (2007) cautioned that vegetable oil processing wastewater
generated during oil washing and neutralization may have a high content of organic
material and subsequently, a high biochemical oxygen demand (BOD) and chemical
oxygen demand (COD). Wastewater may also have a high content of suspended
solids, organic nitrogen, and oil and fat, and may contain pesticide residues from the
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treatment of the raw materials. Therefore, all such wastewater should be properly
treated before allowing it for use.
Pandey et al. (2008) have demonstrated the wastes of a vegetable oil refinery
at 35oC and at a pH of 1.9 contained the following loads (all in mg/): TDS = 7600, oil
and grease (7782), COD=29120, sulfides (8.4), sulfates (2.0), phosphates (7.4), heavy
metals – Pb (0.02), Cd (0.03), Cr (0), Zn (1.2), Mn (0.04), Ni (0.25), Fe (1.4) and Cu
(0.03). The wastewater released by the industry contained various emulsifiers,
biocides (metallic and nonmetallic solids), antioxidants and other chemical additives.
The wastewater had fatty substances in dispersed and non-dispersed forms. The
wastewater from boiler had alkalinity with the TDS in the range of 298-332 mg/L.
The phosphate in the boiler’s wastewater was found to be in the range of 7.0-11.5
mg/L. Ahmad et al. (2009) reported the characteristics of palm oil mill extract. They
found that the effluent was acidic in nature (pH 4.7) with high concentration of oil and
grease (4000 mg/L), an increased biochemical oxygen demand (25000 mg/L), COD
(50,000 mg/L) with a total solid content of 40500 mg/L of which suspended solids
were 18000 mg/L while total volatile solids were 34000 mg/L. Total nitrogen
concentration was 750 mg/L while total ammonical concentration was 35 mg/L.
Amongst different elements identified were Phosphorus (180 mg/L), Potassium (2270
mg/L), Magnesium (615 mg/L), Calcium (439 mg/L), Boron (7.6 mg/L), Iron (46.5
mg/L), Manganese (2 mg/L), Copper (0.89 mg/L) and Zinc (2.3 mg/L).
Aslan et al. (2009) characterized two different wastewaters that originated
from corn oil and sunflower oil refining processes. The aims for characterization of
wastewaters included: total and soluble chemical oxygen demand, total and soluble
biological oxygen demand, suspended solid, oil and grease, pH, total kjeldahl
nitrogen, ammonia nitrogen, total phosphor, phosphate, color and sulfate analyses. In
corn oil wastewaters, total COD is portioned as 80% soluble COD, 20% particular
COD, 3.4% total soluble inert COD, 0.5% total particular inert COD, whereas in
sunflower oil wastewaters soluble COD, particular COD, total soluble inert COD,
total particular inert COD are found as 81.7%, 18.3%, 1.9%, and 5.1%, respectively.
In our characterization studies, BOD5/COD ratio were 0.15 and 0.2 for corn oil and
sunflower oil wastewaters, respectively. These results indicate that wastewaters are
not suitable for biological treatment. But investigation of COD fractions has pointed
out that wastewaters contain mostly biodegradable organic substances.
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2.1.2. Distillery
Pandey et al. (2007) conducted physico-chemical analysis of effluent released
from distillery which was of red brown in colour with unpleasant odour of Indol,
Sketol and other sulphur compounds. Its temperature was 28.5oC. The average pH
value of the distillery effluent was 6.4. Dissolved Oxygen (DO) in the distillery
effluent was not found, but BIS range was 4-6. The absence of DO is possibly due to
high organic load, the average value of total solid in distillery effluent is ~255 far
from the BIS recommended value of 100. The value of BOD in distillery effluent was
544.4 whereas recommended value of BIS is about 30 indicating high organic load.
The COD value of the distillery effluent was found to be 2433.3 mg/l while the
recommended level by BIS is 250 only; which may be due to high organic load.
The effluent from a Lucknow - based distillery (Mohan Meakin Distillery)
was analyzed by Pandey et al. (2008) for physico-chemical and biological parameters
of pollution and concentration of potentially toxic heavy metals (Cd, Cr, Ni and Zn).
The effluent was of wine red in colour and highly acidic (pH ~ 5.5) in nature and
possessed decaying alcoholic smell. The effluent contained high values of different
pollution parameters, particularly total solids, 3450 mgl-1 (soluble plus suspended
solids), alkalinity 1500 mgl-1, biological oxygen demand (BOD, 1649 mgl-1) and
chemical oxygen demand (COD, 2036 mgl-1). It had very low values of dissolved
oxygen (DO, 0.34 mgl-1). The heavy metals (Cd, Cr, Ni and Zn) content, particularly
the nickel concentration (0.029 mg l-1) was high.
2.1.3. Sugar Mill
Arora et al. (2006) performed physico-chemical analysis of sugar mill effluent on
studied its impact on seed germination of vegetable crops and reported increased level
of depletion in dissolved oxygen which was either nil or negligible along with high
values of BOD (1311.66 mg/l), COD 5 (1883 nmg/L), MPN (114250/100ml) and SPC
(48.33×10 /ml). They further reported significant variability for seed germination
among the crops studied and maximum seed germination of Solanum melongena was
found at 5% effluent whereas in case of Lycopersicon esculentum maximum
percentage of seed germination was recorded at 100% effluent and it was equal to
control set used in the study. The study suggested dilution of effluents for its use for
irrigation purpose.
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Baskaran et al. (2009) studied effect of sugar mill effluent polluted soil on
green gram. The sugar mill effluents had higher amount of suspended solids,
dissolved solids, BOD, COD, chloride sulphate, nitrates, calcium and magnesium.
The bioremediated soil showed a good germination of green gram seeds in their study.
Further, the polluted soil were mixed with some organic amendments like coir waste,
vermicompost, Rhizobium and cow dung to improve the soil fertility and their
efficacy was tested by growing green gram plant in that soil and among the
amendments, the vermin-compost mixed polluted soil showed good morphological
and yield parameters.
Samuel and Muthukrarrupan (2011) studied effect of sugar mill effluents,
which contain high amount of suspended solids, dissolved solids, BOD, COD,
chloride, sulphate, nitrates, calcium and magnesium etc. on crops and reported that
continuous use of these effluents harmfully affects the crops. He studied physico-
chemical parameters of sugar mill effluent and contaminated soil taking various
concentrations (0%, 10%, 25%, 50%, 75 % and 100%) of the effluent on seed
germination, germination speed of paddy (Oryza sativa L.) and found low effluent pH
(4.20), total dissolved solids (TDS, 1480mg/L) and chemical oxygen demand (COD,
3140mg/L) for sugar effluent. In his study, germination percentages and germination
values decreased with increasing concentration of effluent in the rice seeds tested.
2.1.4. Paper Mill
Himabindu and Reddy (2005) analyzed paper mill effluent for physical and chemical
parameters and found that nutrients like Mg, Ca, S, K and Cu were found to be higher
in effluents which are useful in the synthesis of pigments. Chlorophyll a and b were
enhanced in effluent irrigated plant over the control and significant increase in total
chlorophyll and carotenoids was also recorded by them.
In another study, Sharma et al. (2005) observed acidic (pH 3.6) nature of the
paper mill effluent with higher BOD and COD.
2.1.5. Battery Industry
A simple, fast and easy to perform method, was used for the quantification of the
inhibitory effect of Battery manufacturing industry’s effluent on Raphanus sativus L.
and Trigonella foenumgracum L by Kumar et al. (2009). Varying concentrations (25,
50, 75, 100 %) of effluent were used to observe influence on seed germination and
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root elongation. The effluent was alkaline in nature (pH 7.4), slight pungent in odour
and muddish in colour. Cu, Cr, Cd, Ni, Pb and Mn concentrations (2.68, 0.12, 0.26,
1.26, 0.18, 0.12 mg/l, respectively) were found to be higher than the prescribed ISI
standard for potable and irrigation water, whereas Fe and Zn concentration (0.24 and
4.64 mg/l, respectively) were found to be within the limit.
2.1.6. Petrochemical Industry
Based on extensive GC/MS screening analyses, Botaloua et al. (2009) characterized
the molecular diversity of petrochemical effluents discharged to a river in North
Rhine-Westphalia. Within a wide spectrum of organic wastewater constituents,
specific compounds that might act as source indicators have been determined. This
differentiation was based on (i) the individual molecular structures, (ii) the
quantitative appearance of organic compounds in treated effluents and (iii) the
information on their general occurrence in the technosphere and hydrosphere.
Principally, site-specific indicators have been distinguished from candidates to act as
general petrochemical indicators. Further, monitoring of environmental behaviour of
target organic contaminants in an aquatic system soon after their release into the river
allowed a first evaluation of the impact of the petrogenic emission in terms of the
quantity and spatial distribution. The identification of petrogenic contaminants was
not restricted to constituents of the effluents only, but also comprised the compounds
circulating in the wastewater systems within a petrochemical plant. A number of
environmentally relevant and structurally specific substances that are normally
eliminated by wastewater treatment facilities were identified. Insufficient wastewater
treatment, careless waste handling or accidents at industrial complexes are potential
sources for a single release of the pollutants. This study demonstrates the relevance of
source specific organic indicators to be an important tool for comprehensive
assessment of the potential impact of petrochemical activities to the contamination of
an aquatic environment.
2.1.7. Dyeing and Tannery Industry
Mondal et al. (2005) studied the impact of pollution due to tanneries on groundwater
regime in Dindigul town in upper Kodaganar river basin. Detailed analysis for
groundwater quality was conducted. The dissolved chemical constituents in
groundwater and their concentration have been studied. High values of correlation
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were observed between EC and Cl, and EC and Na. Progressive reduction in
correlation coefficients for Mg2+
, (Na+ + K
+), Ca
2+ and SO4
2– was observed as 0.91,
0.87, 0.86 and 0.56, respectively. It was found that the quality of groundwater in this
area has deteriorated mainly due to extensive use of chemicals (NaCl) in the leather
industries.
Balakrishnan et al. (2008) studied the impact of dyeing industrial effluents on
the groundwater quality in Kancheepuram (India). Twenty groundwater samples were
collected from various parts of the dyeing industrial region and the samples were
analyzed with standard analytical methods. The concentrations of total dissolved
solids (1138 to 2574 mg/L), chloride (216 to 847 mg/L), total hardness (225 to 760
mg/L), sulphate (64 to 536 mg/L), nitrate (up to 58 g/L), iron (up to 2.3 mg/L) and
lead (up to 0.281 mg/L) were found to be higher and exceeded the permissible limits
of BIS and WHO standards. The user specific water quality indices (USWQI) of each
groundwater sample were evaluated for both purposes. The USWQI of the
groundwater samples varied from 85 to 30 for drinking purpose and 89 to 50 for
irrigation purpose.
Sahu et al. (2008) carried out the toxicity assessment of tannery effluent in
terms of percent phytotoxicity and shoot/root dry weight ratio. The effluent used in
the study was collected from the outlet of an effluent treatment plant situated in the
Jajmau area of Kanpur (Uttar Pradesh), India. The concentration of heavy metals in
the effluent was found to be Cr = 0.135, Cu = 0.065, Zn = 0.052, and Ni = 0.036
mg/L.
Dhanam and Arulbalachandran (2009) conducted experiments to to understand
the effect of different concentrations of TANFAC effluent on seed germination and
seedling growth of five varieties of black gram (Vigna mungo (L.) Hepper). The
TANFAC effluent is having a higher amount of organic and inorganic element. The
Physico-chemical analysis showed that it was acidic in nature. It was rich in total
suspended and dissolved solids with large amount of Biological Oxygen Demand
(BOD) and Chemical Oxygen Demand (COD). The effluents severally affect crop
plants and soil properties when used for irrigation. The growth parameters such as
germination percentage root length shoot length, number of lateral roots, fresh weight
and dry weight were taken on 10th day. All the parameters were found to increase at
10% effluent concentration and it decrease from 25% effluent concentration onwards.
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Among black gram, variety V-2 was tolerant to TANFAC effluent when compared to
other varieties.
2.1.8: Fertilizer Industry: Pollution effects of fertilizer factory’s effluent on growth
and development of corn and rice seedlings were studied by Mishra and Singh (1987).
The effluent was found to be rich in various solids, biochemical oxygen demand
(13013), N+, Ca
2+, Na
+, Cl
−, Co3
2− and HCO3
−, deficient in dissolved oxygen and
highly alkaline in nature.
2.1.9. Dairy Mill
Bhatnagar and Gupta (2002) studied nature and quality of soil impaired by dairy
effluents to ascertain the feasibility of use of the effluents for establishment and
growth of trees and forage crops suited to the desert region. The impact of the
effluents on soils was studied by examining the physico-chemical characteristics of
soil (treated and virgin soil) in comparison to due standards use for irrigation of soils.
Arora et al. (2005) studied physicochemical and bacteriological characteristics
of Aachal Dairy mill effluent and its effects on seed germination of some agricultural
crops. They found that effluent was highly polluted and carry high load of organic
contents as evident by total absence of dissolved oxygen and enhanced value of total
solids.
Uaboi-Egbenni et al. (2009) analyzed physico-chemical parameters like pH,
electrical conductivity, total dissolved solids, chemical oxygen demand (COD),
biological oxygen demand (BOD) and oil level in industrial effluents. Results
obtained show that the main drain (MD) had the highest electrical conductivity (1961
μs, pH 10.43), as well as total dissolved solids (TDS, 977 mg/l). Effluent from
toiletries had the highest concentration of oil (0.121) and the lowest pH (2.75).
Kohle and Pawar (2011) analyzed treated and untreated effluents samples
from dairy industry for physicochemical parameters like pH, temp, color, DO, BOD,
COD, TDS, TSS, TS, Chloride Sulphate, Oil & grease and found vast differences
between two groups of effluents for various parameters.
2.1.10. Mixed Industries
Subbarao et al. (1998) studied groundwater pollution due to discharge of industrial
effluents from a polymers factory in Venkatapuram. Untreated industrial effluent
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from the plant was discharged with total dissolved solids concentrations reaching up
to 6500 mg/l.
Priyadarshani (1998) assessed trace elements in Safi river water in Bachra area
of north Karanpura coal fields of Hazaribagh District showed presence of zinc,
copper, nickel, cadmium, lead, manganese, mercury, cobalt and iron.
The efficiency of alternative treatment processes in producing a final effluent
conforming to regulatory standards with regards to chemical oxygen demand (COD)
and oil and grease (O&G) loads was assessed by Azbar and Yonar (2004). The study
was conducted in three principal stages: waste characterization, lab-scale treatability
studies and full-scale applications. The effluent were characterized in terms of pH
(6.3–7.2), total COD (13,750–15,000 mg l−1
), soluble COD (CODs) (6500–7000 mg
l−1
), biochemical oxygen demand (BOD5) (4300–4700 mg l−1
), O&G (3600–3900 mg
l−1
), total suspended solids (TSS) (3800–4130 mg l−1
), total Kjeldahl nitrogen (TKN)
(636–738 mg l−1
) and total phosphorus (TP) (61–63 mg l−1
).
Heavy metals contamination through industrial effluent to irrigation water and
soil in Korangi area of Karachi (Pakistan) was studied by Saif et al. (2005). For this
purpose, 24 samples from different drains and four tube wells water samples were
collected and analyzed in the year 2000. Similarly, soil and plant samples were taken
from the same area and analyzed to assess their heavy metal contamination. It was
found that Zn was 0.005-5.5, Cu 0.005-1.19, Fe 0.04-5.58, Mn 0.01-1.79, Cd 0.004-
2.4, Cr 0.004- 5.62, Ni 0.02-5.35 and Pb 0.05 to 2.25 mg L-1 in various waste water
samples. It was also noted that 4% samples contained Zn, Cu, Fe and Cr above the
critical values; while 7, 21, 14 and 36% samples were higher than the required values
in Mn, Cd, Ni and Pb, respectively. Similarly, soil analysis (0-20 cm) showed higher
values of Zn, Fe, Mn, Cd, Ni and Pb at some places. Like wise plant samples
(spinach) had greater concentrations of many heavy metals than the recommended
values. However, area irrigated with tube well water was safe and heavy metal
quantities were within the limits in soil and plants.
Tariq et al. (2006) conducted a study to evaluate various industrial effluents of
Hayatabad Industrial Estate (HIE), Peshawar (Pakistan) and assess the possible
impacts of such effluents on quality of underground water. A total 12 samples
including 7 from industrial effluents at the discharge point of each industry (marble,
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matches, steel, aluminum, pharmaceutical, beverages, ghee industries), 1 from main
drain receiving effluents of all industries and 4 from tube or dug wells in the vicinity
of the Estate were collected in March, 2003 and analyzed for temperature, pH,
electrical conductivity, total dissolved salts, total suspended solids, biological oxygen
demand and heavy metal contents (Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn). The
characteristics of effluents varied with the industry. The pH of one effluent (from
aluminum industry) was beyond the limit and of the remaining within the permissible
limit whereas TSS of one effluent (Pepsi industry) was within and of the remaining
beyond the permissible limits comparing with the National Environmental Quality
Standards (NEQS). The BOD was above the permissible limit in almost all of the
effluents. Among heavy metals, Cd, Cr, Cu, Fe and Zn were within the permissible
limits in all but Mn, Ni and Pb were beyond the permissible limits in one or more
effluents. Variable results were also obtained for various parameters in underground
water samples. The pH, TSS, TDS, Fe and Zn were within the permissible limits in all
but Cd, Cr, Cu, Mn, Ni and Pb were above the permissible limits in one or more water
samples compared with the WHO and US-EPA standards established for drinking
water. These results suggested that effluents discharged from various industries
showed variable characteristics and are potential threat to underground water
contamination. It is, thus, recommended that wastewater treatment plants must be
established with each industry. Further, efficient environmental laws and social
awareness program must be undertaken for inhabitants of the estate and in the
surrounding area with respect to potential threat of industrial effluents to the
environment.
Tariq et al. (2008) estimated Levels of selected metals Na, Ca, Mg, K, Fe, Mn,
Cr, Co, Ni, Cd, Pb and Mn by flame atomic absorption spectrophotometry in
groundwater samples from Kasur, a significant industrial city of Pakistan. Salient
mean concentration levels were recorded for: Na (211 mg/l), Ca (187 mg/l), Mg
(122 mg/l), K (87.7 mg/l), Fe (2.57 mg/l) and Cr (2.12 mg/l). Overall, the decreasing
metal concentration order was: Na > Ca > Mg > K > Fe > Cr > Zn > Co > Pb > Mn >
Ni > Cd. Significantly positive correlations were found between Na–Cr (r=0.553),
Na-Mn (r=0.543), Mg–Fe (r=0.519), Mg–Cr (r=0.535), Pb–K (r=0.506) and Pb–Ni
(r=0.611). Principal Component Analysis and Cluster Analysis identified tannery
effluents as the main source of metal contamination of the groundwater. The present
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metal data showed that Cr, Pb and Fe levels were several times higher than those
recommended for water quality by WHO, US-EPA, EU and Japan. The elevated
levels of Cr, recorded as 21–42 fold higher compared with the recommended quality
values, were believed to originate from the tanning industry of Kasur.
Sial et al. (2006) conducted a study at Hattar Industrial Estate extending over
700 acres located in Haripur district of North West Frontier Province (Pakistan) which
is a new industrial estate and has been developed with proper planning for
management of industrial effluents. The major industries located in Hattar are ghee
industry, chemical (sulfuric acid, synthetic fiber) industry, textile industry and
pharmaceuticals industry. These industries, although developed with proper planning
have been discharging their effluents in the nearby natural drains and ultimately
collected in a big drain near Wah. The farmers in the vicinity had been using these
effluents for growing vegetables and cereal crops due to shortage of water. They
collected the water samples from sewage and normal tap water samples in vicinity of
these industries and analysed them for pH, electrical conductivity (EC), total soluble
salts (TSS), biological oxygen demand (BOD), chemical oxygen demand (COD), total
nitrogen, cations and anions and heavy metals. The effluents of ghee and textile
industries were found to be highly alkaline. EC and TSS loads of ghee and textile
industries were also above the National Environmental Quality Standards (NEQS),
Pakistan. All the effluents had residual sodium carbonates (RSCs), carbonates and
bicarbonates in amounts that cannot be used for irrigation. Total toxic metals load in
all the effluents is also above the limit i.e. 2.0 mg/L. Copper in effluents of textile and
sewage, manganese in ghee industry effluents and iron contents in all the effluents
were higher than NEQS.
In a comparative study of effluent from dairy farming, municipality sewage,
textile industry and tap water, Shrestha and Niroula (2006) found that Dairy Farming
effluent was associated with high pH (7.4) and small amount of organic matter. The
Municipality Sewage contained high organic matter while high solute particles (1.7
g/l) were found in Textile industry effluent. The highest value of dissolved oxygen
(4.15 mg/l), lowest value of solute particles (0.4 g/l) and negligible organic matter
were found in tap water.
Singh and Chandel (2006) analyzed the heavy metal content in the industrial
effluents from Jaipur (Rajasthan). For the characterization of heavy metals of various
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industrial effluents, some heavy metals, like Arsenic, Cadmium, Chromium, Copper,
Iron, Manganese, Nickel, Lead and Zinc were analyzed. The results exhibited that As,
Cd, Cr and Pb were not found in any studied wastewater samples, while some of the
following heavy metals ranged from : Cu (0.0 . 1.0 mg/L), Fe (0.1 . 0.4 mg/L), Mn
(0.0 . 0.4 mg/L), Ni (0.01 . 0.07 mg/L) and Zn (0.68 . 60.84 mg/L). Copper, Iron,
Manganese and Zinc were found above the standard limit recommended by IS: 3307
(1977). However, Nickel was found below the regulated safety values for all studied
samples.
Uaboi-Egbenni et al. (2009) investigated the industrial effluents from 5
different industrial concerns in Lagos, Nigeria. They studied the physical parameters
of the effluent including pH, electrical conductivity, total dissolved solids, chemical
oxygen demand (COD), biological oxygen demand (BOD) and oil level. Results
obtained show that the main drain (MD) had the highest electrical conductivity (1961
μs, pH 10.43), as well as total dissolved solids (TDS, 977 mg/l). Effluent from
toiletries had the highest concentration of oil (0.121) and the lowest pH (2.75).
Accumulation and distribution of toxic metals in wheat (Triticum aestivum L.)
and Indian mustard (Brassica campestris L.) irrigated with distillery and tannery
effluents were assessed by Chandra et al. (2009). Analyses of effluents and soil
samples have shown high metal content than the permissible limit except Pb.
Nagajyothi et al. (2009) also analyzed industrial effluent released by the
power plant. The effluent was of alkaline in nature (pH 8.5), odorless and comprises
heavy metals such as Cr (0.071 mg l-1
),Cu (0.014 mg l-1
), Mn (0.036 mg l-1
), Fe (0.05
mg l-1
),Co (0.31 mg l-1
), Ni (0.041 mg l-1
),Cd (0.028 mg l-1
), Pb (0.108 mg l-1
) and Zn
(6.73 mg l-1
).
Ahmad and Goni (2009) estimated concentrations of Cu, Zn, Pb, Cr, Cd, Fe,
and Ni in soils and vegetables grown in and around an industrial area of Bangladesh.
The order of metal contents was found to be Fe > Cu > Zn > Cr > Pb > Ni > Cd in
contaminated irrigation water, and a similar pattern Fe > Zn > Ni > Cr > Pb > Cu >
Cd was also observed in arable soils. Metal levels observed in different sources were
compared with World Health Organization, SEPA, and established permissible levels
reported by different authors. Mean concentration of Cu, Fe, and Cd in irrigation
water and Cd content in soil were much above the recommended levels.
20
The critical review on analysis of effluents from different industries indicated
presence of pollutants in varying quantity. Presence of heavy metals and dissolved
solids were mainly responsible for polluting water streams and soils due to discharge
of industrial effluents.
2.2. Effect of industrial effluent on growth, yield and phenology of different plant
species
2.2.1. Distillery
Behera and Misra (1982) analysed the effect of industrial effluent on growth and
development of rice seedlings. The effect of industrial effluent of a molasses distillery
on growth and development of rice (Oryza sativa L.) seedlings showed that high
concentration of effluent altered the normal pattern of rice seed germination. At 5, 10,
20, and 50% (v/v) effluent concentrations, the coleoptile emerged before the
emergence of root primordia. The green colour development of the coleoptile was
delayed with the increase in the effluent concentration. Percentage of germination,
viability, branching in roots, shoot and root length, fresh weight, and dry weight of the
rice seedlings showed negative relationship with the effluent concentration. The
cations and anions in shoot and root of rice seedlings (control) was found to be the
same, whereas in the effluent-treated rice seedlings relatively high amount of
potassium and sodium and low amount of chloride was found in roots compared to
shoots. But the amounts of phosphorus, magnesium, and calcium were almost in same
quantity in both, root and shoot.
Kannan (2001) studied the effect of distillery effluent on commonly cultivated
crop plants (Phaseolus aureus and Pennisetum typhoides) under laboratory
conditions. He found that with 100 per cent effluent irrigation, the germination was
badly affected. However, 1% effluent and 5% effluent irrigation was helpful in
increasing the vigour index of the crop plants.
Pandey et al. (2002) assessed effect of 0%, 25%, 50%, 75% and 100%
distillery effluent concentrations on germination of various plant species and reported
that the seed germination percentage in wheat (98±57%, 93±50%, 89±33%, 82±28%
and 77±20%), sweet pea (100±0%, 98±1%, 90±33%, 70±1.15% and 65±1.52%) and
lady's finger (96±1%, 91±1%, 79±66%, 76±0.005% and 73±1% ).
21
A field experiment with groundnut as test crop was conducted by Ramana et
al. (2002) to evaluate the manurial potential of three distillery effluents: raw spent
wash (RSW), biomethanated spent wash (BSW) and lagoon sludge (LS) vis-à-vis
recommended fertilizers (NPK + farm yard manure (FYM)) and a control (no
fertilizer or distillery effluent). It was found that all the three distillery effluents
increased total chlorophyll content, crop growth rate (CGR), total dry matter, nutrient
uptake (N, P and K) and finally seed yield compared to the control but inhibited
nodulation and decreased nitrogen fixation. Among the three distillery effluents, BSW
produced the highest seed yield (619 kg ha−1
) twice that of control (3.10 kg ha−1
),
followed by RSW (557 kg ha−1
) and LS (472 kg ha−1
). However, the distillery
effluents did not influence protein and oil contents. It was concluded that these
distillery effluents because of their high manurial potential could supply nutrients,
particularly potassium, nitrogen and sulphur, to the crops and thus reduce the fertilizer
requirement of crops. Nevertheless, the crop performance and yield with three
distillery effluents were overall less than that produced by recommended NPK + FYM
probably on account of failure of the effluents to supply balanced nutrition to the
plants for achieving their potential growth capacity.
In another study, Ramana et al. (2002) assessed effect of different
concentrations (0%, 5%, 10%, 15%, 20%, 25%, 50%, 75% and 100%) of distillery
effluent (raw spent wash) on seed germination (%), speed of germination, peak value
and germination value in some vegetable crops: tomato, chilli, bottle gourd, cucumber
and onion. The distillery effluent did not show any inhibitory effect on seed
germination at low concentration except in tomato, but in onion the germination was
significantly higher (84%) at 10% concentration as against 63% in the control.
Irrespective of the crop species, at highest concentrations (75% and 100%), complete
failure of germination was observed. The speed of germination, peak value and
germination value also followed a similar trend. They found that a concentration of
5% was critical for seed germination in tomato and bottle gourd, and 25% in the rest
of the crops. Based on the tolerance to distillery effluent, the crops studied have been
arranged in the following order: cucumber > chilli > onion > bottle gourd >tomato.
Further, they concluded that the effect of the distillery effluent was crop-specific and
due care should be taken before using the distillery effluent for pre-sowing irrigation
purposes.
22
Suthar et al.
(2005) studied the impact of distillery effluent on seed
germination and seedling growth of some plants. They reported that the percent of
seed germination in Vigna radiata, Cyamopsis tetragonoloba, Vigna aconitifolia and
Trigonella foenum-graecum was found maximum with treatment of 60% (P<0.001),
80% (P<0.005), 40% (P<0.0005) and 100% (P<0.005), respectively as compared to
control. Similarly, root length and shoot height also showed maximum values with the
range of 20-40% distillery effluent concentration as compared to control (P<0.001).
Nevertheless, increased concentration of distillery effluent significantly inhibited the
plant development.
Pandey et al. (2007) conducted physico-chemical analysis of effluent released
from distillery and studied effect of distillery effluent on seed germination of wheat
(Triticum aestivum), pea (Pisum sativum) and lady’s finger (Abelmoschus esculentus),
which was of red brown in colour with unpleasant odour of Indol, Sketol and other
sulphur compounds. They conducted experiment using various concentrations of the
effluents (0%, 25%, 50%, 75% & 100%) and assessed effect on seed germination,
speed of seed germination, peak value and germination value of three selected plant
species and found that germination percentage decreases with increasing
concentration of effluent in all the tested plant species, where as the germination
speed, peak value and germination value increases from control to 25% and 50%
concentration and decreases from 50% to 75% and 100% effluent.
Pandey et al. (2008) studied effect of contaminated water possessing toxic
heavy metals (Cd, Cr, Ni and Zn) on germination and seedling growth of corn or
maize (Zea mays) and rice (Oryza sativa) and found that maize and rice can be grown
on mild acidic soils as there was less reduction in growth and grain yield.
Petri-dish experiment was conducted by Nath et al. (2007) to study the effect
of different concentrations of distillery effluent on pulses. The higher concentration of
the different elements (already present in effluent), Biological Oxygen Demand and
Chemical Oxygen Demand affected the seed germination, seedling growth and
ultimately plant growth and yield. The petridish experiment, using effluent of one of
the distillery of Lucknow region, on seed germination and seedling growth in pea and
black gram revealed that potassium content of distillery effluent adversely affected
seed germination, seedling growth (radicle and plumule size), number of lateral roots,
total chlorophyll, total amylase, fresh weight, dry weight, moisture content and water
23
absorption. Therefore, the higher concentration of effluent was found to be toxic, but
can be used for irrigation purpose after proper treatment and dilution.
A study performed by Pandey and Nautiyal (2008) on pollution level in
distillery effluent and its phytotoxic effect on seed germination and early growth of
maize and rice exhibited that use of distillery effluent, even on 1:1 dilution with tap
water, inhibit germination and early seeding growth of maize and rice. In both maize
and rice, more so in the former, germination % of seeds, length of radicle and plumule
and fresh and dry weight of the seedling were significantly reduced. The observations
suggested that the effluent, as discharged from the distillery, carry a heavy load of
pollutants. Their discharge into the river posed a potential threat to the aquatic life
particularly during summer months when the water flow in river is drastically
reduced. The distillery effluent was also found to be harmful for irrigating crops
growth along with drain carrying it. Pandey and Neraliya (2002) studied effect of
distillery effluent on seed germination, seedling growth, chlorophyll and protein
contents of chickpea (Bengal gram) and observed several mutations with altered
growth and varying levels of chlorophyll and seed protein.
Kannan and Upreti (2008) studied the influence of distillery effluent on
germination and growth of mungbean (Vigna radiata) seeds. Experimental effects of
untreated (raw) distillery effluent, discharged from a distillery unit (based on
fermentation of alcohol from sugarcane molasses), and the post-treatment effluent
from the outlet of conventional anaerobic treatment plant (treated effluent) of the
distillery unit were studied in mungbean (Vigna radiata). Mungbean seeds were
presoaked for 6 h and 30 h, respectively, in different concentrations (5–20%, v/v) of
each effluent and germination, growth characters, and seedling membrane enzymes
and constituents were investigated. Results revealed that the leaching of
carbohydrates and proteins (solute efflux) were much higher in case of untreated
effluent and were also dependent to the presoaking time. Other germination characters
including percentage of germination, speed of germination index, vigor index and
length of root and embryonic axis revealed significant concentration-dependent
decline in untreated effluent. Evaluation of seedlings membrane transport enzymes
and structural constituents (hexose, sialic acid and phospholipids) following 6 h
presoaking of seeds revealed concentration-dependent decline, which were much less
24
in treated effluent as compared to the untreated effluent. Treated effluent up to 10%
(v/v) concentration reflected low-observed adverse effect levels.
2.2.2. Power Plant
In an experiment, Nagajyoti et al. (2008) studied the effect of industrial effluent from
a power plant on groundnut (Arachis hypogaea L.) seedlings. The distribution of
heavy metals in the soils and corresponding accumulations in the experimental crop
was investigated on different experimental days 10, 15, 20, 25 and 30th day. The
metals Cr, Cu, Mn, Fe, Co, Ni, Pb, Cd and Zn in plants and soil samples were
analyzed by AAS technique. In Arachis hypogaea plants Fe was high in 100%
effluent at 10, 15, 20, 25th days. It has been observed that at 25% effluent
concentration, there is growth in the root length, an increase in shoot length,
germination percentage, Chl a, chl b, total chlorophyll content in Arachis hypogaea L.
chlorophyll content have increased up to the 20th day (2.929, 1.607, 4.536 mg/g fw)
and then decreased from 25th day (1.670, 0.832, 2.149 mg/g fw) onwards.
Nagajyoti et al. (2009) conducted a pot culture experiment to study the effect
of power plant’s effluent on seed germination, seedling growth and chlorophyll
content of green gram variety ‘LGG 460’ at different effluent concentrations and time
intervals. The effluent is alkaline in nature (pH 8.5), odorless, and had heavy metals
viz., Cr, Cu, Mn, Fe, Co, Ni, Cd, Pb and Zn. The germination percentage of seed,
seedling growth and chlorophyll content showed a gradual decline with increase in
effluent’s concentration. They found positive effect of 25% effluent concentration on
root length, shoot length and total chlorophyll content during initial 20 days. Later
(after 20 day of treatment) declining trend was observed for all growth parameters.
However, at higher concentrations of the effluent, toxic effects were observed from
20th day onward. The study indicated that the power plant’s effluents can be used
safely for green gram cultivation only after proper treatment and dilution.
2.2.3. Petrochemical Industry
Suitability of petrochemical industry wastewater for irrigation was assessed by Aziz
et al. (1995) in a field experiment conducted at the Experimental Farm of Indian Oil
Corporation Limited, Mathura Refinery, Mathura (India), to study the effect of treated
wastewater in comparison with ground water on four cultivars of wheat on the basis
of growth, yield and grain quality. It was noted that wastewater increased all growth
25
and yield parameters. Soil irrigated with wastewater showed no significant changes in
pH, total organic carbon, calcium, water soluble salts, cation exchange capacity and
SAR. Treated refinery wastewater met the irrigational quality requirements as its
physico-chemical characteristics were within the permissible limits.
2.2.4. Vegetable Oil
Salimon (2007) conducted a study to see the effect of palm oil mill effluent (pome)
on soil properties, growth, nodulation and yield of cowpea (Vigna unguiculata) in
palm oil producing zone of Nigeria. He conducted experiments at the two main
producing locations of Ekpoma and Calabar both in rainforest ecological zones of
Nigeria. The experiments had four treatments with three replications and arranged in
completely randomized design (CRD). The treatments were applied at 0ml-T0, 40ml-
T1, 80ml-T2 and 120ml-T3 concentrations in the pots of 2 kg soil. Then 3 seeds of
cowpea (dual purpose variety) were planted in each pot. The germination test
indicated the seed in the control plot sprouted better than those for the POME treated
pots. Soil analysis was carried out before and after POME application and planting of
cowpea. Results showed that effluent supplies nutrients to the soil, improves
infiltration rate and aggregate stability. The effluent retarded growth of cowpea at the
early stage, enhances nodulation when applied in a controlled manner and inhibits
nodulation when applied in large quantity. It was suggested that POME can be used as
organic fertilizer material to improve degraded, sandy, and low organic matter soils.
2.2.5. Food Processing Industry
Pimentel et al. (2009) analyzed the plant effluents from the cashew nut processing
plant which is a major industry in almost all northeastern States of Brazil. The
technical cashew nut shell liquid (CNSL), which contains mainly cardanol, cardol,
polymeric material, and traces of methyl-cardol, is the most abundant bye-product of
this process. The high level of CNSL in the effluent generated during production is a
potential environmental toxin. They assessed the toxicity of this industrial effluent,
specifically two of its major components, cardol and cardanol, using the brine shrimp
(Artemia sp.) lethality assay. Effluents were collected at a cashew nut processing plant
located in Fortaleza, Ceará, Brazil. Cardol and cardanol were isolated from the
technical CNSL. The LC50 of cardol was 0.56 and 0.41 mg/L after 24 and 48 hr
exposures, respectively, and of cardanol was 1.59 and 0.42 mg/L. The LC50 values
26
for crude effluent were 1.38 and 0.60 % after 24 and 48 hr exposures, respectively,
and were 2.16 and 0.88 % for treated effluent. Data from this study suggested that the
cashew nut industry effluents are highly toxic to the environment. The current
treatment strategy to minimize the toxicity of this industry’s effluent is insufficient
and must be improved.
Ehiagbonare et al. (2009) studied the effect of cassava effluent on Okada
environment. Two sets of same five plant species Sida acuta, Icacina trachanta,
Euphorbia hirata, Tridax procumbens and Chromelaena odorata (all these plants are
used as ethnic medicinal plants) were germinated and irrigated with cassava effluent
for 10 days at alternate days. One part of the effluent had read palm oil in it from
processing while a part of it had non-significant results were obtained from the one
without red palm oil. Only Chlomolaena odorata survived out of the five plant
species. The survival was 5% in 100% effluent concentration, 20% survival in 75%
effluent concentration, 35% survival in 50% effluent concentration whereas control
had 100% survival. Results from the effluents with red palm oil were non-significant.
2.2.6. Fertilizer Industry
Mishra and Singh (1987) studied the pollution effects of fertilizer factory effluent on
growth and development of corn (maize) and rice seedlings. They found that Effluent
at low concentrations of 2.5 and 5% (v/v) had non-significant effect on seed
germination but enhanced the growth and development of seedlings of both test crops.
Higher concentrations of effluent, however, reduced seed viability and percentage
germination and caused deleterious effects on growth and development. The greening
of the coleoptile was delayed at higher effluent concentrations. The concentrations of
Na+, Ca
2+, Na
+ and Cl
− in the shoot and root systems of control seedlings of corn and
rice were similar whereas in effluent-treated seedlings, a relatively high amount of
Na+ and low amount of Cl
− was found in the roots as compared to the shoots, but the
amount of Ca2+
was similar in both.
Singh et al. (2006) studied the impact of fertilizer factory effluent on seed
germination, seedling growth and chlorophyll content of gram (Cicer arietinum) and
found that the germination percentage of seed, seedling growth and chlorophyll
content showed a gradual decline with increase in effluent concentration. However, at
higher concentrations of the effluent toxic effects were observed at 21 days. The study
27
suggested that the effluent can be used safely for Cicer arietinum cultivation, only
after proper treatment and dilution.
2.2.7. Tannery
Bala (1994) studied the effect of tannery effluent on germination and growth
of selected pulse and cereal crop plants. The Study was carried out to assess the
impact of tannery effluent on seedling growth of Vigna radiata, Cajanus cajan and
Sorghum bicolor plants under laboratory conditions. The values of germination
percentage, seedling growth, chlorophyll content and phytomass accumulation
increased over control set with corresponding increase of effluents concentrations.
Bera et al. (1999) studied the effect of tannery effluent on seed germination,
seedling growth and chloroplast pigment content in mungbean (Vigna radiata L.
Wilezek). They studied the effect of different concentrations of tannery effluent on
seed germination, seedling growth and chloroplast pigments in mungbean (Vigna
radiata L. Wilczek) cv Pusa Baisakhi. It was suggested that tannery effluent can
never be employed in the field directly or at higher concentration but can be utilized
as a liquid fertilizer only for certain crops at 2.5% dilution level.
Singh and Joshi (2001) studied the genotoxic effect of tannery effluent in
Allium cepa L. in effluents collected during rainy season. They showed that tannery
effluent collected during the rainy season depressed the mitotic division to
considerable extent in the root meristem of Allium cepa L. The capability of treated
cells to recover from the mitotic depression declined gradually.
2.2.8. Sugar Mill
Arora et al. (2006) reported the impact of sugar mill effluent on seed
germination on certain agricultural crops. In their study variability was found on the
impact of effluent on percentage of seed germination of agricultural crops. Maximum
seed germination of Solanum melongena was found at 5% effluent. In case of
Lycopersicon esculentum maximum percentage of seed germination was recorded at
100% effluent, which was equal to control set used in the study.
Ayyaswami et al. (2008) studied the impact of sugar factory effluent on the
growth and biochemical characteristics of terrestrial and aquatic plants. The physico-
chemical characteristics of sugar industry effluent were measured and some were
found to be above those limits permissible in the Indian irrigation water standard. A
28
pot study was initially conducted to study the effects of different concentrations (20%,
40%, 60%, 80% and 100%) of sugar factory effluent on seed germination, seedling
growth and biochemical characteristics of green gram and maize. A similar study was
also carried out using the aquatic plants, water hyacinth and water lettuce. The higher
effluent concentrations (above 60%) were found to affect plant growth, but diluted
effluent (up to 60%) favored seedling growth.
2.2.9. Pulp and Paper Mill
Chakravarthi et al. (1995) analyzed paper mills effluent effect around Shri
R.R. Paper mill area as the cultivators are using this paper mill effluent for irrigation.
From physico-chemical characteristics calculated values of Sodium Absorption Ratio
(SAR) and, Percent Sodium (PS), the quality of effluent was established by the
researchers.
Singh et al. (2002) assessed the agropotentiality of the effluent coming out
from century pulp and paper mill, Lalkuan (Uttaranchal) on wheat (Triticum aestivum
var. UP 2329) crop grown in two soils differing in texture with different effluent
concentrations. Diluted effluent increased the chlorophyll content, plant height, shoot
and root biomass, grain yield, protein, carbohydrate and lipid contents in wheat
grains, while undiluted effluent caused inhibition in plant growth resulting in a sharp
decline of yield. Pure soil provided better growth and yield results than the soil mixed
with sand.
Bhargava and Bhargava (2005) studied the effect of paper mill effluent on
seed germination and seedling growth of Vicia faba. They found considerable
increase in growth and yield at lower and decreased growth and yield at higher
concentrations of the paper mill effluent. Effluent concentration promoted both seed
germination and seeding growth at 5% concentration and higher concentration inhibit
both seed germination and seedling growth. The observation also indicated organ
specific differences in the growth of seedlings in presence of different concentrations
of paper mill effluent.
Himabindu et al. (2005) in their study to see the effect of paper board mill
effluents on biochemical characteristics of rice reported that owing to the higher
content of nutrients like Mg, Ca, S, K and Cu in effluents which are useful in the
29
synthesis of pigments. They found that Chlorophyll-a and b were enhanced in effluent
irrigated plant over the control. Significant increase in total chlorophyll and
carotenoids was also recorded.
A study was carried out by Kumar (2005) to see the impact of paper mill
effluent on germination percentage and seedling growth of Phaseolus aureus with
different concentrations of effluent. The results showed that lower concentration was
in favour of germination and seedling growth while there was gradual decrease in
germination and seedling growth on higher concentration. The maximum inhibition in
seed germination and seedling growth was found in pure effluent.
Malla et al. (2005) in their study to see the effect of paper mill effluent on
germination of green gram found that the effluent significantly inhibited germination
of root and shoot length. The biochemical injury did not appear spontaneously but
with the increase in effluent treatment there is reduction in observed biochemical
parameters which are negatively correlated. The shoots of the seedlings were found to
be resistant; whereas roots of the seedlings susceptible to paper mill effluent
treatment.
Effect of paper mill industry effluent on chlorophyll content of some
medicinal plants was studied by Sharma et al. (2005). They found that the chlorophyll
content showed a decreasing trend in the selected plants Colotropis procera R. Br.
and Solanum xanthocarpum Schard & Wendl. growing around the industry, under the
impact of paper mill effluent as compared to plant irrigated with normal water.
Tyagi et al. (2005) studied the impact of paper mill industry effluent on
germination and early growth performance of Achyaranthes aspera Linn. and Ricinus
communis. They found that the germination was completely inhibited at 25% dilution
in Ricinus communis whereas it was delayed up to 7th day of treatment in
Achyranthes aspera. The root length was greatly inhibited in 50% and 100% dilution.
The study revealed that in general amongst treated sets the shoot length and root
length, fresh wt. and dry wt. of the selected medicinal plant were maximum with 50%
dilution on 5th, 7th and 9th day but lower than the control.
2.2.10. Textile and Dyeing Industry
Kumawat et al. (2001) studied effect of dye industry effluent on germination
and growth performance of two winter season (rabi) crops namely, wheat and
30
chickpea and reported less adverse effect on germination at lower concentration, but
pronounced effect on growth of the different crop cultivars. Genotypic variability with
respect to tolerance were also noticed which have suggested selection of appropriate
cultivars for cultivation in areas where crop is likely to receive irrigation water
containing dye industry effluent.
Gupta and Bishwas (2005) investigated the effect of effluent of a dye industry
at Varanasi (India) on the seed germination, seedling growth and chlorophyll content
of Withania somnifera. They found that the increasing concentration of the effluent
induced gradual reduction in the germination percentage and seedling growth.
Physico-chemical characteristic of the dyeing industry effluent were also analysed.
Rajeshwari et al. (2005) reported effects of effluents from a medium sized dye
house on plant growth and soil characteristics. They found that diluted effluent
enhanced the plant growth while deleterious effects were noticed at higher levels.
Accumulation of various substances was also formed in the soil. In general the
effluent was not suitable for irrigation.
In order to assess as to whether treated textile effluent could be safely used to
irrigate some winter vegetables, experiments were conducted under controlled
conditions in growth room by Rehman et al. (2008). Varying levels of treated and
untreated textile effluents were applied to germinating seeds of some winter
vegetables and their effect was assessed on germination and early growth stage using
seed germination, growth, and biochemical attributes. From the results, it was obvious
that textile effluent reduced seed germination and early growth of all vegetables.
However, this effect was more pronounced at the highest concentration of textile
effluent. Furthermore, treated textile effluent did not show any inhibitory effect on
seed germination of all vegetables. Photosynthetic pigments such as chlorophyll a and
b, and protein contents were higher in the leaves of all vegetable plants irrigated with
treated textile effluent than those of supplied with untreated textile effluents. It has
been observed that heavy metals were lower in concentration in treated textile effluent
as compared with untreated textile effluent. However, germination and growth
responses of all three vegetables were different to treated or untreated textile
effluents. Furthermore, the Raphanus sativus ranked as tolerant followed by Brassica
campastris and Brassica napus based on germination and growth responses.
31
Researchers further concluded that in view of shortage of water, textile effluent could
safely be used for irrigation to vegetables after proper processing.
Ogunwenmo et al. (2010) studied effects of brewery, textile and paint effluent
on seed germination of two leafy vegetables (Amaranthus hybridus and Celosia
argentea) belonging to family Amaranthaceae through soaking of seeds in effluents
(50 and 100% concentrations) and observed differential response for duration of
soaking and effluent concentrations for two vegetables. They suggested that industrial
effluent had negative effect on seed germination therefore effluents should not be
used for irrigation without treatment.
2.2.11. Dairy Industry
Bhatnagar and Gupta (2002) studied nature and quality of soil impaired by dairy
effluents to ascertain the feasibility of use of the effluents for establishment and
growth of trees and forage crops suited to the desert region. The impact of the
effluents on soils was studied by examining the physico-chemical characteristics of
soil (treated and virgin soil) in comparison to due standards use for irrigation of soils.
Arora et al. (2005) studied physicochemical and bacteriological characteristics
of Aachal Dairy mill effluent and its effects on seed germination of some agricultural
crops. They found that effluent was highly polluted and carry high load of organic
contents as evident by total absence of dissolved oxygen and enhanced value of total
solids.
Gaikar et al. (2010) studied the impact of various concentrations (viz. 10, 20,
30, 40, 50, 60, 70, 80, 90, and 100%) of Dairy effluent on seed germination and early
seedling growth of soybean. It was observed that increase in effluent concentration
there was a corresponding decrease in % germination but seedling growth gradually
increased up to 50% effluent concentration. Whereas 10% dilution of effluent
enhanced seed germination and 100 % effluent completely inhibit both, seed
germination and seedling growth. They suggested that the effluent could be used as
liquid fertilizer up to 50% dilution.
2.2.12. Battery Industry
In the study of Kumar et al. (2009) on battery industry effluent’s effect on
Raphanus sativus L. and Trigonella foenumgracum L. it was observed that effective
concentration of the effluent for certain degree of inhibition was different but both the
32
plants had a reduced seed germination and reduced radicle growth with increase in
concentration. The germination percentage of seeds showed non-significant increase
at 25% effluent while all other treatments showed inhibition of germination.
2.2.13. Metal Industry
Tmam Khasim et al. (1994) studied the effect of chromium translocation from
farm soil contaminated with chromate industrial effluents into plants. In this study
farm soil samples contaminated with industrial chromium were studied for its
translocation and accumulation pattern in different plant parts of Arachis hypoegea
(peanut plant) and Cicer arietinum L. (gram plant) at different growth periods. The
total chromium accumulation pattern in both the plant species was found in roots,
leaves, shoots and seeds. The most edible part of the plants showed least or
insignificant accumulation of chromium irrespective proximity to root.
Jain et al. (1994) investigated the effect of different concentrations of heavy
metals on root nodulation in Vigna anguiculata. Pot experiments were performed to
evaluate the variation in root nodulation when different concentration of heavy metals
was present. Nodulation was found to be the best in presence of lead and least in the
presence of mercury.
Islam et al. (2006) studied the impact of industrial effluents on plant growth
and soil properties from an aluminum plant at Bangladesh. For this purpose a pot
experiment was conducted with rice and grasses grown on normal agricultural and
contaminated soils (treated with industrial effluent) to evaluate the effect of the
effluents on soil and plant growth. The contaminated soil exerted significant (p≤0.05)
negative effects on the growth, straw yield and nutrition of rice and grass grown on it.
The more reduction (reduction over control, ROC: 55 to 67% for rice and 30 to 68%
for grass) of straw dry matter yields of rice at different stages was determined as
compared to grass grown on contaminated soil. The contents of N, P and K in the rice
plants grown on the contaminated soil were decreased by 28, 32 and 65%,
respectively. While increased (increase over normal agricultural soil, i.e. control:
IOC) S and Na contents in rice by 55 and 1010% but decreased the S and Na contents
in grass by 200 and 114%, respectively. Available N was determined 12 to 22 times
higher in normal agricultural soil, while available S content was obtained 3 to 5 times
33
higher in contaminated soil at different time of sampling. Type of crop showed no
influence on N, P and S status of the soils.
Kumar (2006) reported the effect of steel factory effluent on the seed
germination and seedling growth of Phaseolus mungo cv.T9 and showed that
increasing concentration of effluent induced a gradual decrease in germination
percentage. The maximum seedling growth occurred in 25% concentration of effluent
and minimum at 100%.
2.2.14. Mixed Industries
Ravichandran and Kannan (1993) studied the impact of industrial effluent
from dye and match industry on the growth and metabolism of Phaseolus mungo L.
The analysis of dye and match industrial effluents revealed that they are highly
polluted. A study of the impact of these effluents on the growth and metabolism of
Phaseolus mungo L. showed that percent germination and seedling length decreased
with an increase in concentration of these effluents. There was a reduction in fresh
weight and biomass accumulation (dry weight) that paralleled a decline in pigment
content of the plant. This may be due to the degradation of chlorophyll caused by
increased peroxidase activity. The soluble protein and in vivo nitrate reductase activity
followed a declining trend, while the level of L-proline showed an increasing trend
with an increase in concentration of these effluents. The increase in leaf nitrate
content at higher concentrations of effluents may be due to the high nitrate content in
these effluents. Comparing these two industrial effluents, the effluent from the dye
industry was found to be more toxic to the plant than that of the effluent from the
match industry.
Vijayarengan and Lakshmanachary (1994) studied differential nickel tolerance
in green gram cultivars. They reported that soaking the seeds of four green gram
cultivars in aqueous solution of nickel sulphate at 50 mg/ lt for 12 hours, prior to
sowing, exhibited cultivar specific differences on the growth and yield reduction.
Among the four cultivars, KM 2 was the most sensitive, ADT2 and ADT 3 were
intermediate in sensitivity and AG 2160 was the least sensitive to nickel treatment.
Sharma and Habib (1996) analyzed various parameters of rubber factory
effluent and observed high magnitude of pollution. Various parameters, viz., pH,
34
BOD, COD, chloride, free CO2, oil and grease violated tolerance limits. TSS, TDS
and heavy metals like Cr, Pb, Zn, Fe and minerals like Na, K, Ca, Mg, S04, P04 and
Total N2 indicated organic and inorganic load. Concentration of Ca, K, P04 and Total
N2, crude protein and ether extract was significantly lower in the seeds of effluent
treated cultivar Pant P 5 of Pisum sativum.
Ghimire and Bajracharya (1996) in their study on three different industrial
effluents viz. carpet dyeing, tannery and steel reported that the effluents of carpet
dyeing industry possessed comparatively low concentration of various ions with
moderate range of pH whereas the effluents of tannery and steel industries possessed
high concentrations of metallic as well as non-metallic components, with extreme
range of pH and high conductivity value. Al, Cr, Na, ammonical nitrogen and
chlorides were present in high concentrations in tannery effluents. Similarly, Al, Cr,
Zn, Fe and ammonical nitrogen were present in excess in steel effluent.
Prasanthi and Rao (1998) studied the effect of industrial effluents and polluted
waters on germination of crops. They conducted studies to evaluate the effects of
industrial effluents and polluted waters on seed germination of crops. Two effluent
samples and two wastewater (polluted) samples were collected from Kattedan
Industrial Development area, Hyderabad and a bioassay test was conducted. The
effluents and wastewaters were unsuitable for irrigation and there is a need to treat
and dispose of them scientifically.
The effects of multiple industrial-pollutant sources on the groundwater system
were evaluated in the Industrial Development Area (IDA) of Medak district, Andhra
Pradesh (India). The quality of groundwater in the region has been affected negatively
due to the discharge of effluents on open land and into ponds, tanks, and streams.
Water samples from surface-water bodies, dug wells, and bore wells were analyzed
for their major ion concentrations. The high values of electrical conductivity (EC) and
concentrations of Na+, Ca
2+, Cl
–, and HCO3
– indicate the impact of industrial
effluents. Based on the hydrochemistry, the groundwater is classified into various
types, such as sodium-chloride, sodium-bicarbonate, calcium-chloride, and
magnesium-chloride, and its suitability for drinking and irrigation has been found to
be hazardous (Subramanyam and Yadaiah, 2001).
35
Shukry (2001) conducted an experimental study to study the effect of
industrial effluents polluting the river Nile on growth, metabolism and productivity of
two crop species, wheat (Triticium aestivum) and faba bean (Vicia faba). Pot
experiments using loamy soil were conducted to evaluate the effect of irrigation with
industrial effluents on growth, uptake on growth, uptake of nutrients and yield of
wheat (Triticum aestivum cv. Giza 164) as a monocot and faba bean (Vicia faba cv.
Giza 461) as a dicot plant. Also, irrigation by industrial effluents in combination with
vesicular-arvesicular mycorrhiza (VAM) was used in trying to use a biological control
to overcome the harmful effects of heavy metals pollution. Irrigation of plants with
industrial effluents leads to marked changes in growth criteria depending on plant
and/or the stage of growth. Industrial wastewater led also to marked changes in total
carbohydrates and nitrogen in both shoots and roots. On the other hand, combination
of industrial waste water with VAM caused an increase in the total carbohydrates and
total nitrogen in shoots and roots of both wheat and bean plants. The yield
components in wheat and bean were significantly increased with industrial effluents,
but the biochemical concentrations were different. In wheat, the carbohydrate
concentrations were increased but protein- N and total-N were decreased, however,
mineral contents, especially Zn were increased. The reverse response was recorded
with VAM. For bean the opposite occurred. Generally, bean plants were more
sensitive to pollution with heavy metals, than those of wheat however this could
influence be overcome by using VAM with irrigation.
Rajkhowa and Barua (2001) studied effect of foaming water on germination
and seedling growth of some cereals and pulses and revealed significant reduction in
seed germination and growth of seedlings due to formation water. Increase in the
dilution percentage of foaming water to the extent of 50-75 per cent showed
significant improvement in seed germination and growth of seedlings of different
crops. Authors have advocated utilization of formation water for irrigation purpose
after proper treatment and dilution to the extent of 75 per cent.
Crowe et al. (2002) studied the effects of an industrial effluent on plant
colonization and on the germination and post-germination growth of seeds of
terrestrial and aquatic plants. The vast volumes of process-treated waters (effluent)
from major oil sands industrial companies in Alberta (Canada) are held within large
dyed tailings ponds. Toward testing viable options for reclamation, various
36
hummock–wetlands systems have been constructed; in addition, natural wetlands
(inhabited by obligate wetland plant species) have become established as a result of
seeping of the effluents held within the large dyked ponds. Vegetation surveys
conducted on and around the industrial site revealed that the constructed wetlands
associated with the dyke drainage (effluent treated with phosphorous) and
consolidated tails (CT; effluent treated with gypsum) had low biodiversity and were
not invaded by many aquatic plants. Although the natural wetland was also not
invaded by many aquatic species, it was found to be as diverse as the reference
wetlands (i.e. off-site wetlands not exposed to the effluents). Exposure to oil sands
effluents had an inhibitory effect on the germination (percent and/or rate) of several
plant species (tomato, clover, wheat, rye, pea, reed canary grass); clover and tomato
seed germination were most affected. Two treatments in particular (effluents from the
natural on-site wetland and the CT constructed wetland), delayed germination, and
also led to reduced fresh weight of seedlings of tomato, wheat, clover and loblolly
pine. The osmolarity of the effluents associated with the natural on-site wetland and
CT constructed wetland were 712 and 728 mOs/kg, respectively substituting these
effluents with solutions of polyethylene glycol of the same osmotic potentials had a
greater inhibitory effect on germination rate. The negative effects of the effluents on
seed germination may account for the paucity of aquatic species that invaded the oil
sands impacted wetlands. This factor will also be critical in determining the long-term
feasibility of hummock–wetland systems.
Municipality sewage and effluents from Dairy Farming and textile industry
were chosen to assess the germination activity of pea (Pisum sativum L. var. Arkel) by
Shrestha and Niroula (2003). The effluents from Municipality Sewage and Dairy
Farming inhibited seed germination while textile industry effluent promoted. The
effluent from Municipality Sewage and Dairy Farming delayed seed germination
during early hours i.e., 24 hours of sowing. The inhibition was maximum in the
Municipality Sewage effluent where as the germination percentage never exceeded
48% even after 120 hours of sowing. The dilution experiment revealed that the
effluent of Municipality Sewage was still inhibitory up to 25% (v/v) concentration
while the inhibitory effect of Dairy Farming was overcome at 50% (v/v)
concentration. The textile industry effluent was safe for seed germination at all
dilution.
37
Gulfraz et al. (2003) conducting a study to evaluate the suitability of industrial
effluent for irrigation purposes and their possible effects (due to heavy and trace
metals) on the germination as well as quality of agricultural crops. The effluents
(liquid waste) of five industries like textile mill, oil refinery, soap and detergent,
hydrogenated oil and rubber industry were used in this study. The results showed that
effluents from all five industries consist higher concentration of metals (Cr, Mn, Fe,
Cu, Co, Ni, As, Cd and Pb).
Nawaz et al. (2006) studied the effect of industrial effluents on seed
germination and early growth of Cicer arietinum L. Water samples were collected
from three different industries of Rawalpindi (Pakistan), which were Koh-e-Noor
Textile Mill (KNM), Marble Industry (MI) and Attock Refinery Limited (ARL). Two
different varieties of Cicer arietinum L. (P-91 and P-2000) were selected to grow in
these effluents. Physicochemical parameters {pH, temperature, Dissolved Oxygen
(DO), conductivity, turbidity, Total Dissolved Solids (TDS), Total Suspended Solids
(TSS) etc.} of these samples were analyzed. Both varieties were grown in different
dilutions of effluents. With the increase in effluent concentration, growth of plants
was found more affected in Koh-e-Noor mill effluent while, less effect was seen in
Marble and ARL effluents. Increase in root and shoot lengths were observed in these
effluents at different concentrations. Fresh weight was less in Koh-e-Noor mill
effluent as compared to control. Dry weights of plants were greater in most of the
treatments. Variety P-91 was more tolerant as compared to P-2000.
Pande (2006) studied physico-chemical characteristics of a brewery effluent
(Mohan Meakin’s brewery, Lunknow). Brewery effluent treated seedlings of Cajanus
cajan (Linn.) and Vigna mungo (Linn.) showed reduced seed germination, radicle
length and plumule length whereas use of diluted effluent (50% with distilled water)
produced less severe effects. The study revealed that brewery effluent use for
irrigation without proper treatment induced phytotoxic effects in plants.
Umebese and Onasanya (2007) studied the effect of Minta effluent on the
phenology, growth and yield of Vigna unguiculata (L.) Walp Var. Ife brown. The
effluent was highly acidic (pH 3.74) and the concentrations of Ca, Mg and SO4 were
appreciable (107.07, 351.47 and 221.11 mg L-1
, respectively). Germination of seeds
sown in effluent was delayed by a day, reduced by 2% and non-synchronous.
Phenological investigations showed that plants grown in soil watered with effluent
38
had 4-5 days delay in staking, bud formation, flower initiation, fruiting, pod ripening
and plant senescence. These plants showed significant reductions in plant height, leaf
area, shoot biomass and pod biomass (p<0.05). Furthermore, seed yield and 100 corn
weight of treated plants were low. The authors concluded that minta effluent has low
agro-potential.
A combinatorial effect of distillery and sugar factory effluents in crop plants
was studied by Nath et al. (2007). Under the reutilization and recycling strategy of
industrial effluents, treated distillery and sugar factory mixed effluent was used in
petridish culture experiments to investigate its effect on seed germination and
seedling growth in wheat, garden pea, black gram and mustard. The seed germination
and seedling growth were significantly reduced with increase in concentration of the
effluent. The fresh weight was found significantly increased in barley (1.16 g per
seedling in 25% dilution level of effluents in comparison to 0.93 in control), while
other higher dilution levels reduced it. Inhibition in fresh seedling weight was
observed in wheat, garden pea, black gram and mustard. Dry weight was found
consistently reduced or unchanged in different treatments. Total chlorophyll contents
in barley were significantly increased in different treatments (2.351 and 2.721 mg/g
fresh weight of tissue at 25, 50% dilution levels in comparison to 1.781 of control)
while in other crop it was reduced all over the treatments. Amylase activity in wheat,
garden pea, black gram and mustard was reduced in all the treatments. Only in barley
its level was enhanced from 0.76 to 0.85, 0.96, 0.81 in 25, 50, 75% dilution levels of
the effluent mixture, respectively. Based on the data of different crops barley was
found to be highly tolerant as the 25 and 50% dilution levels of combined effluents. It
showed no change in germination %, while seedling growth was increased in lower
dilution levels of combined effluent as compared to control barley>garden
pea>wheat>black gram>mustard gradually showed increased level of sensitivity,
respectively. Most detrimental effects were seen on mustard. This toxicity might be
due to excess of nutrients, beyond the limits of tolerance. Therefore, the higher
concentration of mixed effluent was not advisable for irrigation purpose, however it
could be used for irrigation purpose after proper treatment and dilution (one part
treated effluent and five parts of available irrigation water), as this dilution level was
found growth and yield promontory.
39
A multicentric study was undertaken by Industrial Toxicology Research
Centre, Lucknow (Kisku et al. 2000) for assessing productive utilization of effluent–
contaminated agricultural land, mobilization and statistical analysis of potentially
toxic elements in soil and plants of fields irrigated with mixed industrial effluent.
Total Fe, Mn, Zn, Cu, Pb, Ni and Cr were estimated in soil and plant species of
contaminated and non-contaminated sites. 18 plants species and 18 root adjacent soil
samples from contaminated Kalipur area and 11 plants species and 11 root adjacent
soil samples from uncontaminated Madhabpur area comprising major crops,
vegetables and weeds have been included in the study. It was revealed that Hibiscus
esculentus, Lycopersicon esculentum and Luffa acutangula growing in effluent–
contaminated field show mobilisation ratio <0.5 for most of the PTE (Potentially
Toxic Elements) like Cu, Pb, Ni, Cr and Cd and normal morphology. Surprisingly,
weeds in particular, show high mobilization ratio >0.5 and simultaneously exhibit
healthy gigantic morphology at the early flowering stage. Coriandrum sativum,
Raphhanus sativus, Solanum melongena, Spinace oleracea, Oryza sativum, Brassica
oleracea showed mobilization ratio >0.5 but maintained normal growth. Based on
mobilization ratio and external morphology, the authors suggested the cultivation of
plants H. esculentus, L. acutangula, L. esculentum in land irrigated with industrial
effluent. The highest and second highest enrichment factor (EF) was found for Cd and
Pb, respectively. Pearson's correlation coefficient indicated that the metal level in soil
is not the main factor governing metal uptake. This study will help in selecting plant
species for cultivation in contaminated fields.
Ahmad and Goni (2009) assessed effect of industrial effluent on the vegetable
crops it was seen that accumulation of the heavy metals in vegetables studied was
lower than the recommended maximum tolerable levels proposed by the Joint
FAO/WHO Expert Committee on Food Additives (1999), with the exception of Cd
which exhibited elevated content. Uptake and translocation pattern of metal from soil
to edible parts of vegetables were quite distinguished for almost all the elements
examined.
The study of Uaboi-Egbenni et al. (2009) showed that effluents from
industries affected the time of flowering and fruiting of okra when compared with the
control. The mean number and mean weight of fruits produced were also affected,
although the extent varies from effluent to effluent. The effect was more pronounced
40
in toiletries and plastic effluents where the mean values for fruit numbers was 3 and
mean weight of 17.4 g. However, the mean weight for paint was higher than toiletries.
Cross-sections of the experimental okra plants showed that the effluent affected the
anatomical structures of the plant; the effect being more pronounced on okra grown
on MD. The anatomy of the control grown okra was not affected. The leaves of okra
grown on toiletries effluent had a less mean leaf length than those grown on the rest
effluents. The same trend was recorded for the mean leaf width. The stem length of
okra grown on paint effluent had the least mean value and hence most affected. The
highest value for all parameters studied was recorded for the control. There was a
significant difference between the means of length of leaf, stem and leaf width and
those of the control, signifying the effects which industrial effluents could have on the
growth and productivity of plants.
The influence of industrial effluents on intertidal benthic communities in
Panweol, Kyeonggi Bay (Yellow Sea) on the west coast of Korea was studied by
Young et al. (1995). They found that species number and density have decreased
sharply compared with values available for these communities before this area was
heavily industrialized. At a site near the outfall of a sewage treatment plant almost all
pre-existing macrobenthic fauna have disappeared, and the capitellid polychaete
Heteromastus filiformis predominates. Even at a distance of 4 km, species numbers
have decreased rapidly from 22 in 1984 to 4 in 1992 and a previously dominant
polychaete, Perinereis aibuhitensis, declined from 86 individuals m−2
in 1984 to 14
individuals’ m−2
in 1992. High sediment levels of copper (70–323 μg g−1
dry wt), lead
(33–83 μg g−1
) and cadmium (0.5–3 μg g−1
) indicate that industrial effluents have
caused significant sediment contamination. High levels of copper were detected in the
tissues of H. filiformis (450 μg g−1
) and P. aibuhitensis (240 μg g−1
). Bioaccumulation
of copper in the polychaetes is discussed in relation to the catastrophic collapse of the
benthic communities.
Sik et al. (2009) studied the effects of different concentrations of water on
both incoming and outgoing in central biological and chemical wastewater treatment
plant in Manisa (Turkey) organized industrial zone (MOIZ) on the Allium cepa L. root
meristems, having been rooted in distilled water for 48 h. The union bulbs were kept
in the 100% concentrations of the refined water (RW) and of 10, 25, 50 and 100%
concentrations of unrefined water (UW). Distilled water was used for the control
41
samples. It was determined that wastewater reduced the rate of the mitotic division of
different concentrations and increased the mitotic anomalies. Mitotic index was found
to be 33.8, 31.2, 23.6 and 16.7% in the control group, RW, 10% concentration of the
UW, and 25% concentration of the UW, respectively. On the other hand, the rates of
Mitosis / (Anaphase + Telophase) were 0.23, 0.28, 0.42, 0.71 in the control group,
RW, % concentration of the UW, and 25% concentration of the UW, respectively.
Plant growth was interrupted in the 50 and 100% concentrations of the UW and the
mitotic division was inhibited. No anomalies were encountered in the control group.
In the RW, a low rate of anomaly was observed, while in the different concentrations
of the UW, chromosomal aberrations such as high frequency of lagging chromosome,
irregular distribution, polar slips, horizontal division and sticky chromosome were
observed.
Dhanam and Arulbalachandran (2009) conducted experiments to understand the
effect of different concentrations of TANFAC effluent on seed germination and
seedling growth of five varieties of black gram (Vigna mungo L. Hepper). The
TANFAC effluent is having a higher amount of organic and inorganic element. The
Physico-chemical analysis showed that it was acidic in nature. It was rich in total
suspended and dissolved solids with large amount of Biological Oxygen Demand
(BOD) and Chemical Oxygen Demand (COD). The effluents severally affect crop
plants and soil properties when used for irrigation. The growth parameters such as
germination percentage root length shoot length, number of lateral roots, fresh weight
and dry weight were taken on 10th day. All the parameters were found to increase at
10% effluent concentration and it decrease from 25% effluent concentration onwards.
Among black gram, variety V-2 was tolerant to TANFAC effluent when compared to
other varieties.
Effects of Brewery, Textile and Paint Industry’s effluents on seed germination
of leafy vegetables-Amaranthus hybridus and Celosia argentea was studied by
Ogunwenmo et al. (2010). In order to assess the suitability or otherwise of some
industrial wastewater for irrigation purposes, germination experiment was performed
on seeds of Amaranthus hybridus and Celosia argentea presoaked in 50 and 100%
concentration of brewery, textile and paint effluent for 30 min to 3 h. Longer duration
of seeds in presoaked medium (3 h) increased germination rate (0.92) and percentage
42
(95%) of A. hybridus significantly (p<0.05) to optimum level in 50% diluted brewery
effluent. Though, the effluent generated gradual increase in germination of C.
argentea with increasing presoaking period, the maximum germination (25 and 35%)
was below the control untreated seeds (45%). Fifty percent textile effluent favoured
germination in A. hybridus up to the control level (70%) at 2 h with higher rate (0.63).
Germination decreased (45%) significantly (p<0.05) beyond 2 h. One hundred percent
and 50% textile effluent significantly decreased (p<0.05) germination in A. hybridus
(5-20%) and C. argentea (5-10%), respectively, and totally toxic to C. argentea at
100%. The rate and percentage seed germination of A. hybridus and C. argentea
decreased significantly (p<0.05) as the presoaking period increased in paint effluent
becoming toxic beyond 1 and 1½ h, respectively. Industrial effluent may be
environmentally harmful if not properly treated or diluted.
Industrial effluents from various industries had differential response on growth
and phenology of crop plants and forest tree species. However, it has been widely
suggested in all studies that effluents should be used for irrigation purpose only after
proper treatment.
2.3. Acquired toxicity in selected plant species through different industrial
effluents
Somashekar and Siddaramaiah (1991) conducted a study to evaluate
phytotoxicity tests for screening and bio-monitoring complex effluent samples. Seed
germination tests were conducted using three effluent samples from three industrial
sources. Complete inhibition of germination was, however, not observed in any case.
Zea mays and Dolichos biflorus were found to be most sensitive. There occurred a
significant difference in root/shoot length and dry weight between treated and control
samples. Results of definitive tests indicated a linear concentration-effect relation.
The study indicated that phytotoxicity tests involving higher plants have a high
potential for use in the bio-monitoring of industrial effluents because of simplicity and
sensitivity. They concluded that the test employed by them could be suitably adopted
with slight modifications for tropical conditions.
Ghimire and Bajracharya (1996)
while studying degree of toxicity effect of
three different industrial effluents, viz., carpet dyeing, tannery and steel industry on
43
seed germination and seedling growth of four different vegetables (Brasicca juncea,
B. rapa, B. oleraceae and Raphanus sativus) reported that the degree of toxicity
depended both upon the nature and concentration of chemicals present in the effluents
as well as the type of the vegetable seeds. It was found that the toxicity of the effluent
from carpet dyeing industry was less as compared to the effluents from other two
industries. However, the toxicity of tannery effluent was more pronounced on time of
initiation and percentage seed germination, while the toxicity of steel effluent was
more distinctly associated with the inhibition of root growth. The sensitivity response
of four types of vegetable seeds to be toxicants of three different industrial effluents
was also different. In general, B. juncea and B. rapa were comparatively susceptible,
whereas, R. sativus and B. oleraceae were relatively resistant to the toxicants of
industrial effluent. The investigation showed that growth parameters such as seed
germination and seedling growth can be used to assess the degree of toxicity of
industrial effluents.
In an experimental study, Gomez et al. (1998) studied the effect of nickel (Ni)
on the nutrition of tomato plants (Lycopersicon esculentum cv. Marmande). Dry
matter weights of roots, shoots, and fruit were also studied. Plants, receiving 5, 15,
and 30 mg Ni L-1
, were grown in nutrient solution, and roots, stems plus branches,
leaves, and fruit were analyzed at different developmental stages for essential
nutrients. The presence of Ni in nutrient medium affected plant growth, decreasing
dramatically dry matter yield compared to control plants. This plant reduction was
likely due to the disturbances and imbalances of the different essential mineral
elements. The general effect was a decrease in the absorption and accumulation of
these nutrients. The nitrogen (N) content in the plant increased significantly with
increasing Ni treatments, showing a synergetic effect between Ni and N. A positive
interaction between Ni and potassium (K) was also found. In this way, high levels of
Ni in solution caused an increase in K uptake and, however, a decrease in sodium
(Na) absorption (antagonism Na/K). Since, Ni is taken up as Ni2+
, its absorption in
high concentrations decreased significantly the uptake of other divalent cations, such
as Mg2+
, Fe2+
, Mn2+
, Cu2+
, and Zn2+
, with manganese (Mn) being the nutrient showing
the highest restriction in the whole plant (roots and shoots).
Pathak et al. (1999) studied the effect of soil amendment with distillery
effluent for wheat and rice cultivation. Distillery effluent contains a considerable
44
amount of plant nutrients. In a field study soil amendment with diluted post
methylation distillery effluent increased the yield of wheat and rice grown in
sequence. Organic carbon and available potassium content of post harvest soils were
also increased. Saturated hydraulic conductivity, bulk density and volumetric water
content of the soils improved with effluent application. There was no change in pH
after harvest of wheat and rice. The study showed that the effluent could be used as
soil amendment. However, the EC of soil also increased indicating the possibility of
salinity development in the long run with higher levels of effluent application.
An assessment of industrial water of an electronic component manufacturing
unit with electroplating and its subsequent effects on soil and plants receiving the
effluent was done by Burman et al. (2001). The physico-chemical parameters of the
effluent samples showed higher value than that of ground water. The treated effluent
was within the permissible limit. Microtox test was conducted and determined the
degree of toxicity of untreated, treated effluents as well as the water sample collected
at effluent discharge point of river (confluence point). The physico-chemical
parameters of the soil samples were not changed due to irrigation of the treated
effluent, but the concentration of metals were comparatively higher than the control
soil. Higher accumulation of metals was found in the plant parts in naturally growing
weeds and cultivated crop plant irrigated with treated effluent.
Muthusamy and Jayabalan (2001) studied the effect of sago and sugar factory
effluents on physiological and biochemical contents of Gossypium hirsutum L. Plants
were irrigated with 0, 25, 50, 75 and 100% of effluents of both factories. At lower
concentration (25%) of sugar factory effluents had stimulatory effect on all
biochemical contents. Moreover, all concentration of sago factory effluents was found
to have inhibitory effect on all biochemical contents except proline content which
increased with increasing concentration of both the effluents. Plants growing on
adjacent to sago and sugar factories may accumulate the heavy metals found in both
the effluents, at higher levels in plant products and if consumed may have similar
effect on living organisms.
Singh and Joshi (2001) assessed genotoxic effect of tannery effluent (collected
during the rainy season) in Allium cepa and observed depression in mitotic division to
considerable extent in the root meristem. The capability of treated cells to recover
from the mitotic depression declined gradually. Total number of abnormal cells and
45
cells with non clastogenic abnormalities recovered more than those possessing
clastogenic ones and this difference in recovery behaviour was attributed to the
differential degree of damage caused to the cellular and chromosomal systems by the
two classes of aberrations.
Comparative effects of effluents from six major industries viz. Diesel Power
House, Hetaunda Iron and Steel, Hulas Wire, Himalaya Soap and Chemicals, Leather
Industry, Shah Udyog (textile industry) and sub-metropolitan Sewage of Biratnagar
on germination and seedling growth of rice and black gram were studied by Niroula
(2003). Effluent of Himalaya Soap and Chemicals showed toxic lethal effect on both
the test crops. On germination rice remained more sensitive and susceptible to the
toxic effects of industrial effluents but black gram proved to be more tolerant.
Effluents of Diesel power House and Shah Udyog remained toxic for seedling growth
of black gram as their effects were significant while Leather Industry effluent showed
toxic effect on rice for germination as well as seedling growth.
In the study of Gulfraz et al. (2003) on metal contamination in wheat crops
(Triticum aestivum L.) irrigated with industrial effluents, it was found that the
germination of crops was more effected with the effluents of textile mill followed by
soap and detergent, oil refinery and hydrogenated oil, where as less effects were
observed from effluents of rubber industry. Therefore, it was observed that effluent is
not only unfit for irrigation but also for domestic uses due to presence of heavy and
toxic metals and other harmful pollutants.
Shanker et al. (2005) reviewed the chromium toxicity in plants. The toxic
effects of chromium toxicity on plant growth and development include alternation in
the germination process as well as in the growth of roots, stem and leave, and
suggested that presence of chromium in higher quantity may effect total dry metal
production in different plant species. They further reported presence of heavy metals
in the external environment, which leads to different kind of changes in the growth
and developmental pattern of the plant. The plant growth and development are
essential process of life and propagation of the different plant species and these
processes are continuous in nature and depend on external resources present in the
soil and air.
46
Sinha et al.
(2006) studied the implication of metal contamination of
agricultural soil on vegetables and crops in an area of industrial complex Jajmau,
Kanpur (India). They found that accumulation of toxic metal, chromium; in higher
quantity in leafy and food bearing vegetables then the vegetables where edible part is
develop underground. Sinha et. al. also recommended the cultivation of some
vegetables like bitter guard, egg plant, jack tree, maize, okra, etc. in these industrial
areas.
Pandey (2006) studied the accumulation of heavy metals (Cd, Cr, Cu, Ni and
Zn) in Raphanus sativus L. and Spinacia oleracia. Plants of S. oleracea and R.
sativus were raised in uncontaminated alluvial soil using pot culture method and
irrigated with effluent from electro plating industry showed visual toxic symptoms
like stunted growth, necrosis followed by chlorosis in leaves and finally death of the
plants. Severity of toxicity was less in plants treated with diluted effluent (50%).
Sahu (2008) performed toxicity assessment of tannery effluent in terms of
percent phytotoxicity and shoot/root dry weight ratio. The effluent used in the study
was collected from the outlet of an effluent treatment plant situated in the Jajmau area
of Kanpur, India. Three varieties each of rice, pulses and oil seeds containing different
kinds of reserve food materials, i. e., starch, protein and fat were taken for the toxicity
study. The accumulations of heavy metals, i.e., Cr, Cu, Zn, and Ni, by these different
crop varieties through pot culture irrigated with effluent were estimated at maturity.
The concentration of heavy metals in the effluent was found to be Cr = 0.135, Cu =
0.065, Zn = 0.052, and Ni = 0.036 mg/L. The maximum concentration found in the
plant tissue was seen in the mustard variety RS 30, i. e., Cr = 15.2, Cu = 4.4, Zn = 3.2,
and Ni = 2.6 g/g dry weight (d.w.) and the minimum concentration was found in red
gram ‘Bahar’ (Cr = 8.5, Cu = 2.0, Zn = 1.6 g/g d.w.), whereas, 0.98 g/g d.w. of Ni
was found in the Surya variety of rice. The percent phytotoxicity was found to be in
the range of 10.4 to 25.6% amongst the different test varieties. The average percent
phytotoxicity was found to be highest in rice followed by oilseed and pulses. The
shoot/root dry weight ratio ranged between 10.82 to 14.22, with the highest value seen
for rice (Pant Dhan 10) and the lowest for a pulse (red gram var. Bahar). The results
revealed that cultivation of these crops irrigated with the tannery effluent may pose a
potential risk to humans as well as animals because of their bioaccumulation
properties and ability to transfer metals from one trophic level to the next trophic level
47
through the food chain. Since the percent phytotoxicity and shoot/root dry weight
ratio behaves in a similar manner for the effluent, these parameters can be considered
for the assessment of toxicity of industrial effluents.
In a study conducted by Pandey et al. (2008) to assess the pollution level in
distillery effluent and its phytotoxic effect on seed germination and early growth of
maize and rice, it was found that the emerging leaves of the seedlings developed
visible effects of toxicity, some of which resembled the symptoms of nickel toxicity.
The observations suggested that the effluent, as discharged from the distillery, carry a
heavy load of pollutants. Its discharge into the river poses a potential threat to the
aquatic life, particularly during the summer months when the water flow in the river is
drastically reduced. The distillery effluent is also harmful for irrigating crops grown
along the drain carrying it.
Chandra et al. (2009) studied accumulation and distribution of toxic metals
(Cu, Cd, Cr, Zn, Fe, Ni, Mn, and Pb) and their biochemical effect on wheat and
mustard plants irrigated with mixed distillery and tannery effluents. Analyses of plant
samples cultivated with effluent indicated the maximum accumulation of Fe
(340 mg kg−1
in wheat root and 560 mg kg−1
in mustard leaves) followed by Mn and
Zn in root > shoot > leaves > seeds. Maximum increase in photosynthetic pigment
was observed between 30 and 60 days while protein content was found maximum
between 60 and 90 days of growth period in both plants. An increase in
malondialdehyde, cysteine and ascorbic acid antioxidants content was also observed
in root and leaves of treated plants up to 60 and 90 days of growth. They concluded
that wheat and mustard plants irrigated with effluents without adequate treatment are
health hazards for environment, humans and animals.
In a study by Nagajyoti (2009), a pot culture experiment was conducted to
study the effect of biomass power plant effluent on seed germination, seedling growth
and chlorophyll content of green gram (variety LGG 460) were estimated at different
effluent concentrations and time intervals. It was seen that at higher concentrations of
the effluent, toxic effects were observed from 20th day. They suggested that the
effluent could be used safely for green gram cultivation, only after proper treatment
and dilution.
48
In the study, Kumar et al. (2009) on battery industry effluent Raphanus sativus
and Trigonella foenumgracum, the percent phytotoxicity was found increased with
increase in the concentration of effluent and ranged between 33.27 to 86.36 and 10.64
to 55.06% for Raphanus sativus and Trigonella foenumgracum, respectively.
However, the degree of inhibition was more in case of Raphanus sativus as compared
to Trigonella foenumgracum. The findings indicated that Trigonella foenumgracum
had a higher level of tolerance to the effluent as compared to Raphanus sativus during
early growth phase of the seedlings.
Umebese et al. (2009) studied the impact of combined industrial effluent on
metal accumulation, nitrate reductase activity and yield of two cultivars of Vigna
unguiculata (L.) Walp. Combined industrial effluent from Ikeja Central Treatment
Plant, Lagos, was used to irrigate Vigna unguiculata L. Walp (cowpea), cultivars
IT89KD-349 (white) and IT84E-124 (red). The effluent was alkaline (pH 9.8) and had
a significantly higher concentration of Ca (11.53 mg L-1
), NO3 (83.20 mg L-1
), SO4
(22.73 mg L-1
), Cl (15.45 mg L-1
) and Cd (2.16 mg L-1
) than the experimental soil.
Nitrate reductase activity was enhanced almost throughout the period of growth of
both treated cultivars but for the peak at 35 DAP shown by control white. There was a
corresponding increase in the net assimilation rate and a significant increase (p≤0.05)
in the biomass of leaves and pods of treated red cowpea but only the pods of treated
white cowpea. Heavy metal uptake by seeds of treated plants was negligible and this
may be attributed to the high accumulation of Ca by these plants. Undiluted combined
industrial effluent has good agro potential in the cultivation of red cowpea.
It can be concluded on the basis of review of literature that different types of
toxicity symptoms are produced by various industrial effluents. Whenever, pollution
level was high plants had shown very stunted growth to mortality, therefore it has
been suggested that effluents should be allowed to discharge in water streams and soil
only after proper treatment. Effluent treatment plants should be compulsorily installed
/commissioned in all industries to save plants and environment for future generations.
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