international journal of informative & futuristic research...

493 www.ijifr.com

Copyright © IJIFR 2014

Original Paper

International Journal of Informative & Futuristic Research ISSN (Online): 2347-1697

Volume 2 Issue 3 November 2014

Dr. Ravindra W. Gaikwad

Department of Chemical Engineering,

Pravara Rural Engineering College,

Loni, Ahmednagar - Maharashtra

Abstract

Acid mine drainage (AMD), has been a major environmental problem

resulting from the microbial oxidation of iron pyrite in presence of water and

air, affording an acidic solution that contains toxic metal ions. The main

objective of this study was to remove metal ions from acid mine drainage

(AMD) by using Moringa oleifera seed powder (MOSP).Moringa oleifera an

agricultural solid waste by-product has been developed into an effective and

efficient biosorbent for the removal of Cu (II) from acid mine drainage

wastewater. The experimental equilibrium adsorption data were analyzed

by two widely used two parameter equations - Langmuir, Freundlich

isotherms. Langmuir model offered a better fit with the experimental data

than others four isotherm models. The kinetic data were fitted the model with

correlation coefficient greater than 0.99.The result of the present

investigation indicates that Moringa Oleifera seed can be effectively used for

removal of Cu(II) from aqueous solutions.

1. Introduction

Acid mine drainage (AMD) is a serious environmental problem resulting from the weathering of

sulfide minerals, such as pyrite (FeS2) and its polymorph marcasite (α-FeS). It is characterized by a

low pH-value and high levels of sulfate and metals [1,2]. AMD usually contains high concentration of

metals such as iron, manganese, zinc and smaller amount of cadmium, lead, copper, and nickel. The

oxidation of sulfide releases dissolved ferrous iron and acidity into water which subsequently releases

Moringa Oleifera Seed as Low Cost and Effective Biosorbent for Cu (II) Removal

From Acid Mine Drainage

Paper ID IJIFR/ V2/ E3/ 006 Page No. 493- 501 Subject Area Chemical Engineering

Key Words Moringa Oleifera Seed, Biosorption, Copper, Kinetics, Isotherms

494

ISSN (Online): 2347-1697 International Journal of Informative & Futuristic Research (IJIFR)

Volume 2, Issue 3, November 2014 15th Edition, Page No: 493-501

Dr. Ravindra W. Gaikwad: Moringa Oleifera Seed as Low Cost and Effective Biosorbent for Cu (II) Removal From Acid Mine Drainage

other metal ions. AMD’s typically contain high concentration of dissolved iron which may exists

either in reduced form (Fe2+) or in the oxidized form (Fe3+). Acidity in AMD is comprised of

hydrogen ion acidity and mineral acidity (iron, aluminum, manganese, and other metal ions depending

on the specific geologic setting and metal sulfide). There are 20,000–50,000 abandoned mines in the

United States. Many of these mines produce acid mine drainage (AMD). These AMD contains a

variety of heavy metals, which adversely affect over 23,000 km of streams in the United States [3].

Pennsylvania alone has over 25% of all abandoned mine sites listed by the office of Surface Mining

that generates mine drainage. More than 3000 miles of rivers in Pennsylvania alone are polluted with

mine drainage in the nation. If left untreated, the acid drainage can contaminate surface and ground

water, damaging the health of plants, wild life, and fish [4]. When acid mine waters mix with surface

waters there is potential for gross pollution. An ochre (ferric oxide) precipitate can blanket the

receiving water source and kill aquatic flora and fauna. The loss of biological activity could in some

instances devastate the food chain and lead ultimately to fish kills and loss of amenity [5].The

industrial sources of manganese are steel alloy, dry cell battery, glass and ceramic, paint, ink, dye and

fertilizers It also occurs in metal mines, mine drainage, especially in coal fields [6].The best available

technology discharge limits for acid mine wastewater (mg/l) is provided elsewhere [7].The current

technologies for the removal of copper include chemical precipitation, ion exchange, or

electrochemical processes. Many of these methods are not economical, especially when used for the

reduction of heavy metal ions to low concentrations. Hence, there is a need to develop cost-effective

technologies for treating the acid mine drainage wastewater that reduce metal ion concentrations to

environmentally acceptable levels.

Biosorption has the potential to contribute to the achievement of this goal. Biosorption is a process

that uses inexpensive biomaterials to sequester metals from aqueous solutions and the biomaterials

used in this process are termed as biosorbents. The by-products from agricultural, food and

pharmaceutical industries provide economically viable sources of biosorbents; this makes biosorption

an inexpensive alternative treatment method. Several workers have reported on the potential use of

agricultural by-products as good substances for the removal of metal ions from aqueous solutions and

wastewaters [8, 9,10,11, 11,12,13,14,15], Moringa oleifera belongs to the family Moringaceae, which

is native to the sub-himalayan tracts of India. Moringa oleifera seed is abundantly available in India

with no commercial use. Since its fruits and leaves are edible and consumed in all the seasons, trees

are widely cultivated species in India. Due to this, massive amount of seed is produced, which is

being disposed off as waste. The plant contains various amino acids, fatty acids, vitamins and

nutrients [16], glucosinolates and phenolics (flavonoids, anthocyanins, proanthocyanides and

cinnamates) which are the functional groups that are capable of anchoring metals. The bark tissue of

M. oleifera contains 4-(α-L-rhamnopyranosyloxy)-benzylglucosinolate [17]. Every glucosinolate

contains a central carbon atom which is bonded to the thioglucose group (making a sulfated ketoxime)

via a sulfur atom and to a sulfate group via a nitrogen atom. These functional groups containing sulfur

and nitrogen are good metal sequesters from the aqueous solution. Because of the composition of

Moringa oleifera seed powder and its availability Moringa oleifera seed was chosen as a biosorbent

for the removal of Cu (II) from acid mine drainage wastewater .

In the present study, an easy and economic preparation of the adsorbent was carried out and

adsorption experiments have been performed to determine the metal biosorption mechanism. The

main objectives of the present study include is to study the sorption potential of MOS for copper

removal from acid mine drainage wastewater under equilibrium conditions and to understand the

495




kinetics of it. The data from the experimentation were matched with different kinetic models to

recognize the adsorption mechanism.

2. Materials & Methods

2.1 Chemicals

All reagents used were of AR grade. Deionized double distilled water was used during the

experimental studies. Stock solution (1000 mg L-1

) was prepared by dissolving CuSO4·6H2O. This

was further diluted to obtain the desired concentration for practical use. BDH reagent grade HCl,

NaOH and buffer solutions were used to adjust the solution pH.

2.2 Preparation of the biosorbent

Moringa oleifera seeds were collected from local market of Loni (Maharashtra, India), it was dried

and ground in a mill to obtain fine powder. The powder was washed twice with deionized water and

dried at 50oC for 24 h, then boiled in double distilled water by changing the water repeatedly until

water becomes colorless, which specify the removal of water soluble color compounds. The washed

and boiled powder was oven dried at 70oC for 24 h and stored in desiccators to prevent moisture

adsorption before its utilization. This treated Moringa oleifera seed powder is called as MOS.

2.3 Characterization of the adsorbent

Characterization of biosorbent surface and structure hold keys to understanding the metal binding

mechanism onto biomass. The proximate and ultimate analysis of MOSP is presented in Table 1. The

proximate analysis of the coal was carried out by using standard methods (ASTM D 5142-90).

Table 1 Characteristics of moringa oliefera seed (MOS)

Bulk density (g/cm3) 0.6

Moisture content (%) 3.2

Ash content (%) 12

Fixed carbon (%) 21

Carbon(%) 45

Hydrogen(%) 6

Nitrogen(%) 0.9

Sulphur(%) 0.8

Oxygen(%) 48

Percent ash content, moisture content, fixed carbon, and bulk density are also given in Table 1.

Elemental analysis results showed that MOS is composed of 45 % carbon, 6 % hydrogen, 0.9 %

nitrogen, 0.8 % sulphur and 48 oxygen.

2.4 Biosorption procedures

Batch biosorption studies were executed by taking 50 mL of Cu (II) solution with known pH in a 250

mL flask and by adding 200 mg of MOS. The sealed flask was placed in a shaking incubator at a

496




speed of 350 rpm and temperature of 25oC. After 3h, biosorbent was separated using filter paper and

the concentration of metal ion in solution was analyzed by AAS.

A Cyberscan -500 pH meter was used for pH measurements. The pH meter was calibrated using

buffer standard solutions of pH 4.0, 6.0 and 9.0. The metal concentrations in the samples were

determined using atomic absorption spectrophotometer (AAS, Chemito 201 India).

The effect of pH on Cu (II) biosorption was determined by equilibrating the suspensions in solutions

of different pH ranging from 2.0 to 9.0. For the adsorption isotherm studies, the initial metal ion

concentration was varied over a range of 20 to 200 mg L-1

. The concentration of MOS was varied

between 25 to 700 mg to determine the ratio required for optimum biosorption. The interference

caused by the presence of other cations that are normally present in water was checked by the addition

of monovalent Na and K, and divalent Mg and Ca metal solution ranging from 0 to 400 µg mL-1

.

The quantity of metal ion adsorbed onto the MOS, Qe, was computed by the following equation:

eo CCm

VQe (1)

Where, C0 and Ce are the initial and equilibrium concentrations of Cu(II) in solution whereas V and

m are solution volume in dm3

and mass of adsorbent in grams(g), respectively.

3 Result and discussion

3.1 Effect of pH

It is distinguished that pH is the most important factor that controls the biosorption process [18]. The

pH level affects the system of negative charge on the surface of the biosorbing cell walls, as well as

physicochemistry and hydrolysis of the metal. Therefore, initial experiments have been performed to

find out the optimum pH for the metal removal. Percentage removal of the metal ion as a function of

pH is shown in Fig. 1. It has been examined that under highly acidic conditions (pH ≈ 2.0) the amount

of Cu (II) removal was very small, while the sorption had been increased with the increase in pH from

3.0 to 6.0 and then decreased in the range 7.0 and 8.0. The lower removal efficiency at low pH is

apparently due to the presence of higher concentration of H+ in the solution which compete Cu (II)

ions for the adsorption sites of the MOS. With increase in pH, the H+ concentration decreases leading

to increased Cu(II) uptake.

Decreased biosorption at higher pH (pH>6) was due to the formation of soluble hydroxylated

complexes of the metal ions and their competition with the active sites, and as a consequence, the

retention had been decreased again. Therefore further experiments were carried out with initial pH

value of 6. Previous studies also reported that the maximum biosorption efficiency for Cu(II) metal

ion on biomass was observed at pH 6 [19,20,21].

3.2. Effect of biosorbent dose

Biosorption of Cu (II) onto MOSP was studied by changing the amount of sorbent from 0.1 to 0.8 g in

the test solution while maintaining the initial concentration 50 mg mL-1

, pH 6 and contact time 2 h

constant. Biosorption of Cu (II) as a function of biomass shown in Fig. 2, indicates the effect of

sorbent dose on the Cu (II) biosorption by MOSP. Obviously, the biosorption efficiency increased as

the sorbent dose increased, but it remained almost constant when the sorbent dose reached 0.4 g.

When sorbent ratio is small, the active sites for binding metal ions on the adsorbent surface is less, so

497




the adsorption efficiency is low; when biosorbent dose increased more metal ions were adsorbed.

Thus it results in the rise of adsorption efficiency until saturation.

Figure 1 Effect of pH on the removal of Cu(II)

Figure 2 Effect of Dose of Moringa Oleifera Seed Powder on the removal of Cu (II)

3.3 Effect of Initial Concentration

For practical applications, the process design and operation control, the sorption kinetics were very

important. Sorption kinetics in wastewater treatment was significant, as it provides valuable insights

into the reaction and the mechanism of the sorption reactions. Biosorption of Cu(II) onto MOSP at

various initial concentrations had been carried and shown in Fig. 3.

pH

% R

em

ov

al

of

Cu

(II)

Dose (mg)

% R

em

ov

al

of

Cu

(II)

498




Figure 3. Effect of Initial Cu(II) ions Concentration on the removal of Cu(II)

The effect of initial Cu(II) ions concentration on the adsorption efficiency by MOSP was

systematically investigated by varying the initial Cu(II) ions concentration from 50 mg/L -250

mg/L It was observed that the activities of the MOS materials falls sharply with an increase in

initial concentration of Cu(II), the % removal decrease from 88 % to 57 % using MOS.

3.4 Biosorption isotherm

The successful representation of the dynamic adsorptive separation of solute from solution onto an

adsorbent depends upon an appropriate description of the equilibrium separation between two phases

[22]. In order to determine the mechanism of Cu(II) biosorption onto MOS and to evaluate the

relationship between biosorption temperatures, the experimental data was applied to the two-

parameter non-linear isotherm models, i.e. Langmuir, Freundlich.

The Langmuir isotherm theory assumes monolayer coverage of adsorbate over a homogeneous

adsorbent surface [23].

qmCeKaqmqe

1111

(2)

In eq. (2) qm is the monolayer biosorption capacity of the biosorbent (mg.g-1

), qe is the equilibrium

metal ion concentration on the biosorbent (mg g-1

), Ce is the equilibrium metal ion concentration in

the solution (mg L-1

), and KL is the Langmuir biosorption constant (L mg-1

) related to the free energy

of biosorption. The constant qm and KL increased with increase in temperature. The essential features

of the Langmuir biosorption isotherm can be expressed in terms of a dimensionless constant

separation factor (RL), which is defined in eq. (3).

Concentration (mg)

% R

em

ov

al

of

Cu

(II)

499




OL

LCK

R

1

1 (3)

where KL is the Langmuir constant (L mg-1

) and C0 is the initial adsorbate concentration (mg L-1

).

The value of RL indicates the type of isotherm [24]. The values of RL are all in the range of 0-1,

which indicate the favorable biosorption of Cu (II) by MOSP.

Figure 4 Langmuir Isotherm

The Freundlich model assumes a heterogeneous sorption surface [25].

log (qc) = log ( Kf ) + 1/n log ( Ce) (4)

In eq. (4) Kf is a constant relating the biosorption capacity and 1/n is an empirical parameter relating

the biosorption intensity, which varies with the heterogeneity of the material. From the graphs, Kf

values were found to be 0.074 and the n values were found as 1.73. The 1/n values were between 0

and 1 indicating that the biosorption of Cu (II) onto the MOS was favorable at studied conditions.

The high value of R2 indicated that Freundlich model was altogether properly describing the

relationship between the amounts of adsorbed metal ions and their equilibrium concentrations in the

solution. Table 2 gives the statistical empirical data estimated from isotherm equation for the removal

of Cu (II) using Moringa oleifera seeds.

Table 2. Isotherm Constants

Isotherms Constants R2

Langmuir a = 3 b = 4.9x10-3

0.870

Freundlich n = 1.73 k= 0.074 0.999

y = 66.84x + 0.3342 R² = 0.8704

1/

qe

1/Ce

500




Figure 5 . Freundlich Isotherm

4 Conclusion

The experimental investigation concluded that MOSP could be used as potential sorbent, for the

removal of Cu (II) from acid mine drainage water. The batch study parameters; pH of solution,

biomass concentration, were found to be effective on the biosorption processes. The isotherm studies

revealed that the biosorption process followed the Freundlich model and it is the best fit model for the

removal of Cu (II). The maximum biosorption capacity of copper was 32 mg g-1 at an optimum pH 6.

Based on all results, the MOSP as a natural and low-cost biomass can be used as alternative

biosorbent for treatment of waste waters containing Cu (II) ions.

References

[1] D. Mohan, S. Chander,(2001), Single component and multi-component adsorption of metal ions by

activated carbons, Colloid. Surf. A 177,183–196.

[2] D. Mohan, S. Chander,(2006),Single, binary and multicomponent sorption of iron and manganese

on lignite, J. Colloid. Interf. Sci. 299,76–87.

[3] J. Skousen, B. Faulkner, (1996), Overview of acid mine drainage treatment with chemicals, Green

Lands 26 , 36–45.

[4] M.P. Filion, L.L. Siroois, K. Ferguson,(1990), Acid mine drainage research in Canada, CIM Bull.

83 ,33–40.

[5] J.D.F. Robinson, G.A. Robb, (1995), Methods for the control and treatment of acid mine drainage,

Coal Int. 152–156.

[6] J.W. Patterson,(1978),Wastewater Treatment Technology, Ann Arbor Science, MI,.

[7] W.W. Hellier, (1999),Treatment of coal mine drainage with constructed wetlands, in: J.M. Azcue

(Ed.), Environmental Impacts of Mining Activities,Springer-Verlag, Berlin,

[8] P. King, K. Anuradha, S.B. Lahari, Y.P. Kumar, V.S.R.K. Prasad,(2008), Biosorption of zinc

from aqueous solution using Azadirachta indica bark: Equilibrium and kinetic studies, J. Hazard.

Mater. 152 ,324-329.

[9] E.M. Saad, R.A. Mansour, A. El-Asmy, M.S. El-Shahawi, (2008),Sorption profile and

chromatographic separation of uranium (VI) ions from aqueous solutions onto date pits solid

sorbent, Talanta 76 , 1041-1046.

y = 0.0042x2 + 0.5676x - 2.073 R² = 0.9998

Ln Ce

Ln

qe

501




[10] I. Ghodbane, O. Hamdaour,(2008), Removal of mercury (II) from aqueous media using

eucalyptus bark: Kinetic and equilibrium studies, J. Hazard. Mater. 160 ,301-309.

[11] S. Schiewer, S.B. Patil, (2008),Pectin-rich fruit wastes as biosorbents for heavy metal removal:

Equilibrium and kinetics, Biores. Technol. 99 ,1896-1903.

[12] E. Pehlivan, B.H. Yank, G. Ahmetli, M. Pehlivan, (2008),Equilibrium isotherm studies for the

uptake of cadmium and lead ions onto sugar beet pulp, Biores. Technol. 99 ,3520-3527.

[13] A. Bhatnagar, A.K. Minocha,(2010), Biosorption optimization of nickel removal from water using

Punica granatum peel waste, Colloids Surf. B: Biointerfaces 76,544-548.

[14] A. Gundogdu, D. Ozdes, C. Duran, V.N. Bulut, M. Soylak, H.B. Senturk, (2009),Biosorption of

Pb(II) ions from aqueous solution by pine bark (Pinus brutia Ten.), Chem. Eng. J. 153 ,62-69.

[15] O.S. Lawl, A.R. Sanni, I.A. Ajayi, O.O. Rabiu, (2010),Equilibrium, thermodynamic and kinetic

studies for the biosorption of aqueous lead(II) ions onto the seed husk of Calophyllum inophyllum,

J. Hazard. Mater. 177 , 829-835.

[16] P.H. Chuang, C.-W. Lee, J.-Y. Chou, M. Murugan, B.-J. Shieh, H.-M. Chen, (2007),Anti-fungal

activity of crude extracts and essential oil of Moringa oleifera Lam, Biores. Technol. 98, 232–236.

[17] R.N. Bennett, F.A. Mellon, N. Foidl, J.H. Pratt, M.S. Dupont, L. Perkins, and P.A. Kroon,

(2003),Profiling Glucosinolates and Phenolics in Vegetative and Reproductive Tissues of the

Multi-Purpose Trees Moringa oleifera L. (Horseradish Tree) and Moringa stenopetala L., J. Agric.

Food Chem. 51 ,3546–3553.

[18] R. A. Anayurt, A. Sari, M. Tuzen,(2009), Equilibrium, thermodynamic and kinetic 1 studies on

biosorption of Pb(II) and Cd(II) from aqueous solution by macrofungus 2 (Lactarius scrobiculatus)

biomass, Chem. Eng. J. 151 ,255-261.

[19] H. Pahlavanzadeh, A.R. Keshtkar, J. Safdari, Z. Abadi,(2010), Biosorption of nickel(II) from

aqueous solution by brown algae: Equilibrium, dynamic and thermodynamic studies, J. Hazard.

Mater. 175 ,304-310.

[20] N. Fiol, I. Villascusa, M. Martinez, N. Mirralles, J. Poch, J. Seralos, (2006),Sorption of Pb(II),

Ni(II), Cu(II) and Cd(II) from aqueous solution by olive stone waste, Sep. Purif. Technol. 50,132-

140.

[21] X. Li, Y. Tang, Z. Xuan Y. Liu, F. Luo,(2007), Study on the preparation of orange peel cellulose

adsorbents and biosorption of Cd2+ from aqueous solution, Sep. Purif.Technol. 55-75.

[22] J. Febrianto, A. N. Kosasih, J. Sunarso, Y. Jua, N. Indraswati, S. Ismadji,(2009), Equilibrium and

kinetic studies in adsorption of heavy metals using biosorbent: A summary of recent studies, J.

Hazard. Mater. 162,616–645.

[23] I. Langmuir, (1918),The adsorption of gases on plane surfaces of glass, mica and platinum, J. Am.

Chem. Soc. 40 ,1361–1403.

[24] E. Malkoc, Y. Nuhoglu, (2007),Potential of tea factory waste for chromium(VI) removal from

aqueous solutions: Thermodynamic and kinetic studies, Sep. Purif. Tehnol. 54,291-298.

[25] H. Freundlich,(1939), Adsorption in solution, W.J. Helle, J. Am. Chem. Soc. 61 ,2-28.

BIOGRAPHY Dr. Ravindra W. Gaikwad is a chemical engineer and a Professor of Chemical Engineering

at Pravara Rural Engineering College, Loni, affiliated to University of Pune. Dr. Gaikwad has

taught academic courses in mechanical operations, chemical engineering mathematics, process

modeling & simulation, environmental engineering. His research has focused on Modeling,

optimization and removal of heavy metals in Acid Mine Drainage wastewater, with emphasis

in Environmental Technology (Wastewater engineering and solid waste management). The

emphasis is both on the fundamental understanding and modeling of the key heavy metal

removal that take place in environmental systems, and on the development of improved

technologies for the treatment and management of liquid and solid wastes. Dr. Gaikwad has

directed or co-directed research and training projects. He has had the opportunity to lead an

extensive research effort involving field data collection and modeling of the chemical

engineering system. Dr. Gaikwad has authored or co-authored 93 refereed journal articles, 34

professional proceedings papers, and 22 other articles and technical reports. In addition, he has

serving as an independent consulting engineer. He has designed and conducted numerous

short courses and special training programs in process modeling & simulation and

Environmental Engineering.

international journal of informative & futuristic research...

Documents