BIOREMEDIATION OF SOILS AND
GROUNDWATER CONTAMINATED WITH
PHENOLICS, CHLORINATED PHENOLS,
PCP AND CREOSOTES
BIOREMEDIATION OF SOILS AND GROUNDWATER CONTAMINATED WITH PHENOLICS,
CHLORINATED PHENOLS, PCP AND CREOSOTES
Institute of Technology, Sligo
Department of Environmental Science and Technology
By:
Robin Barry
Waste Management
Lecturer:
Dr. Michael Broaders
What is bioremediation?
•"Remediate" means to solve a problem, and "bio-remediate" means to use biological organisms to solve an environmental problem such as contaminated soil or groundwater.
How Does Bioremediation Work?
Uses naturally occurring microorganisms to break down hazardous substances into less toxic or nontoxic substances.
Types Of Bioremediation
• In situ bioremediation - material to be bioremediated dosesn’t leave the site.
• Ex situ bioremediation - material to be bioremediated is
moved to another site to be treated.
Bioremediation Of Groundwater
• In-situ -Almost invariably undergoes in situ bioremediation.
In situ Bioremediation• Soils• Advantages:
• Don’t require excavation of contaminated soils – less expensive, less chance of contaminating other sites.
• Possible to treat a large volume of soil at once.
• Disadvantages:
• May be slow and difficult to manage.
• Require uncompacted soils.
Factors affecting successful bioremediation?
• Site Characterisation
• Microbiological Characterisation
• Environmental Factors
Techniques of bioremediation.
In Situ Bioremediation of Soil • (1) Bioventing
• (2) Injection of Hydrogen Peroxide
Techniques of bioremediation.
• In Situ Bioremediation of Groundwater
• Activated Sludge Reactors
Techniques of bioremediation.
• Ex situ Bioremediation of Soil
• Slurry Reactors
• Landfarming
What is creosote?
Creosote is a product mainly of coal tar but also of wood tar , and is characterized as a brown –black oily liquid having a significant fraction of mixed phenolics (10%)and heterocyclics (5%), along with the PAHs (85%)(Mueller et al.,1989) It is a distillate produced by high temperature carbonization of the tars.
What is creosote used for?
•Wood treatment
•Restricted-use pesticide
•Animal and bird repellant
•Insecticide
•Fungicide
•Animal dip
.
What are the sources of creosote to the environment?
•Discarded products treated with creosote.
•Creosote spill sites.
Seepage of creosote from intertidal sediments at Eagle Harbor. (Photo courtesy of EPA) Wood piling treated with creosote
Cresote’s fate in the environment?
The factors affecting cresoste’s fate
It’s physical and chemical properties.
The KOW of creosote’s components
Creosote’s toxicity
•carcinogenic
• mutagenic
•teratogenic
What are phenols?
phenol
Phenolics are characterised by the presence of an aromatic ring and one or two hydroxyl groups
Phenol Phenol Phenol
Phenol is a colorless or white solid when it is pure; however, it is usually sold and used as a liquid.
Phenols are a large group of naturally occuring ,chemically diverse compounds .
What are phenolics used for?
•Phenolic disinfectants
•Phenolic resins
What are chlorinated phenols?
There are 19 different chlorophenols depending upon the number and arrangement of chlorine atoms on the parent phenol ring .
e.g pentachlorophenol
Toxicity of chlorinatedphenols
The effects of chlorophenols on organisms are reported under the following headings: cytotoxicity, immunotoxicity, embryotoxicity, fetotoxicity, teratogenicity, mutagenicity, carcinogenicity, and
enzymatic/metabolic effects.
generally, molecules with more chlorines are more toxic, due mainly to higher fat solubility as indicated by higher octanol/water coefficients ( K o/w )
Sources of chlorophenols to the
environment
• Forest industry
• Pulp bleacheries
• Biocides
• Industrial Waste streams
• Chlorine treated water
• Microbial breakdown herbicides
Chlorophenols fate in the environment
• Physical and chemical degradative processes ; photodegradation, oxidation, hydrolysis, evaporation/volatilization and sorption
• biological degradative processes such as uptake, breakdown and utilization
HOW BIOREMEDIATION WORKS
“Bioremediation is defined as the process where organic wastes are degraded biologically under controlled conditions to less toxic contaminants or to levels that do not constitute a threat to the environment”.
BIOREMEDIATION IS CARRIED OUT EITHER BY
AEROBIC OR ANAEROBIC REACTIONS
• AEROBIC : SUBSTITUTION OF ONE OR BOTH OF
THE OXYGEN ATOMS IN THE OXIDATION PROCESS
•ANAEROBIC: UTILISATION OF ALTERNATIVE
ELECTRON ACCEPTORS SUCH AS NITRATE, IRON,
MANGANESE, SULPHATE AND CARBON DIOXIDE
BIOREMEDIATION PATHWAYS OF CHLORINATED PHENOLS, PHENOLICS AND
PENTACHLOROPHENOL AEROBIC BIOREMEDIATION
• REACTION INITIATED BY ACTION OF OXYGENASE ENZYMES
• INSERTION OF HYDROXYL SUBSTITUENTS ONTO THE AROMATIC RING
• CP ARE O-HYDROLATED TO CATECHOL
• PCP ARE HYDROLATED VIA P POSITION TO CORRESPONDING CATECHOL
• FINAL END PRODUCTS OF CO2 AND WATER
• COMETABOLISM
• INSERTION OF METHYL GROUPS
ANAEROBIC BIOREMEDIATION
• ALTERNATIVE ELECTRON ACCEPTORS
• REDUCTIVE DECHLORINATION
• PHENOL AS FINAL END PRODUCT OR CONVERSION TO METHANE AND CO2
ISOLATION OF MICROBIAL DEGRADERS OF CHLOROPHENOLS, PENTACHLORPHENOLS AND
PHENOLICS • WHITE ROT FUNGI
• THREE MAJOR CLASSES OF OXIDATIVE ENZYMES ARE THE LIGNIN PEROXIDASES, MANGANESE-DEPENDENT PEROXIDASES AND LACCASES
• LIGNIN DEGRADING ABILITIES
• Phaenerochaete chrysoporium • Phaenerochaete sordida • Trametes veriscolor • ENZYMES ARE IMMOBILISED ON POROUS GLASS OR
SILICA BEADS
Figure 1.4 White Rot Fungus: Trametes versicolor
BIOREMEDIATION PATHWAY OF
CREOSOTE • PAH DEGRADATION BY BACTERIA AND GREEN ALGAE
• SUBSTITUTION OF BOTH ATOMS OF THE OXYGEN MOLECULE
• CATALYSED BY THE ENZYME DIOXYGENASE
• ATTACK OF MULTIPLE SITES
• NON-LIGNINOLYTIC FUNGI AND PROKARYOTIC ALGAE
• SUBSTITUTION OF ONE ATOM OF THE OXYGEN MOLECULE
• CYTOCHROME P-450 MONO-OXYGENASE
ISOLATION OF MICROBIAL DEGRADERS OF
CREOSOTE
Figure 1.5 White rot Fungus: Bjerkandera adusta
ENVIRONMENTAL FACTORS AFFECTING BIODEGRADATION
The main factors influencing in situ contaminant bioremediation include:
oxygen
nutrients
moisture content
pH
redox potential
temperature
bioavailability
These factors can be manipulated in order to optimize the correct conditions.
Why Bioremediation?
ADVANTAGES AND
DISADVANTAGES
The potential advantages of applying biodegradation
principles to the cleanup of contaminated sites include:
• 1. Can be done on site.
• 2. Keeps site disruption to a minimum (very
important in beaches)
• 3. Using a in situ Bioremediation the risk of being
exposed to the contaminant or pollutant is
eliminated.As there is minimal excavation , therefore
contact is reduced.
•5. Eliminates transportation costs and liabilities
•6. Can be coupled with other treatment techniques into a
treatment train.
•7. The costs should be lower than other systems with more
expensive input requirements.
•8. The process of bioremediation is a natural biological process
therefore there is a minimal environmental impact from the
treatment process.There re harmless end products such as carbon
dioxide, water and fatty acids upon completion of the process.
The main disadvantages of bioremediation are :
It does not suit all situations, it is site specific.
The process of bioremediation is generally a slow process (several months) .
All hazardous wastes cannot be degradated many metals destroy and are highly toxic to microorganisms thus no biological degradation can take place.
•Barriers to commercialization
BARRIERS TO COMMERCIALIZATION
1.RESEARCH BARRIERS
2.TECHNICAL BARRIERS
3.ECONOMIC BARRIERS
4.REGULATORY BARRIERS
RESEARCH BARRIERS
1.The inexistence of environmental laws and regulations to the formation of a waste treatment market.
2.The view, that pollution control costs industry money & makes industry less competitive in world markets.
3.Research efforts are generally minimal in many countries & the diffusion of research results into commercial applications is negligible (compared to the other sector affected by technology)
4.Get the knowledge in several areas of science .(Microbial physiology, biochemistry ,genetics, ecology …….)
2.TECHNICAL BARRIERS
1.The speed of bioremediation.
2. Bioremediation must be
specifically tailored to each
polluted site.It require
individualized attention.
3.There are no official
scientific measures for evaluating
the success or failure of
bioremediation.
3.ECONOMIC BARRIERS
1.The majority of the firms
are small & lack sufficient
capital to finance sophisticated
research & product
development programs.
2.The information is kept by
trade secrets & intellectual
protection.
3.Experienced personnel are
in short supply.
4.University programs are
now being establishing for
bioremediation specialists.
REGULATORY BARRIERS
1.Cleanup standards. How clean is
clean? The achievable endpoint for
biodegradation may be limited for
specific pollutants.
2.Standards are still under
development.
3.Law established after pollution
problem
SUMARY OF LEGISLATION:
1. EUROPEAN LEGISLATION
EUROPEAN LEGISLATION
•Directive 75/442/CEE of the Counsel, of 15 of July of 1975, relative
to the residues. (With the modifications of the Directive one of the
Counsel 91/156/CE).
•Directive 78/319/CEE of the Counsel, of 20 of March of 1978,
relative to the residues toxic and dangerous.
•Directive 80/68/EEC Council Directive of 17 December1979 on the
protection of groundwater against pollution caused by certain
dangerous substances
•Directive 86/278/CEE of the Counsel, of 12 of June of 1986, relative
to the protection of the environment and, in particular, of the soils,
in the utilization of the sludge after purifying of agricultural waste.
•Directive 91/156/CEE of the Counsel, of 18 of March of 1991, by the
one that the Directive one of the Counsel is modified 75/442/CEE
relative to the residues.
• Directive 91/689/CEE of the Counsel, of 12 of December of
1991, relative to residues dangerous (with the
modifications of the Directive one of the Counsel
94/31/CE).
• Directive 94/31/CEE of the Counsel, of 27 of June of 1994,
by the one that the Directive one of the Counsel is modified
91/689/CEE relative to the residues dangerous.
• Directive 96/59/CE, of 16 of September of 1996, relative to
the elimination of the polychlorobisphenols and
polychloroterophenols (PCB' s and PCT' s).
• Directive 96/61/CE relative to the prevention and to the
control integrated of the Management (IPPC).
EUROPEAN LEGISLATION
Real Decree 833/88, of 20 of July, by the one that the Regulation for the execution of the Law is approved 20/86 basic of residues toxic and dangerous (BOE N° 182 of 30/07/88).
Order of 13 of October of 1989 (Public Department of Works and Urbanism), by the one that the methods are determined of characterization of the toxic and dangerous residues. (BOE n° 270 of 10/11/89).
Resolution of 17 of November of 1998, by the one that
the publication of the European catalogue is arranged of
residues (CER), approved by means of the Decision 94/3/CE,
of the Commission, of 20 of December of 1993, (BOE, n° 7,
08/01/99).
•· Real Decree 1.378/1999, of 27 of August of 1999, by
the one that are established measured for the elimination and
management of the polychlorobiphenyls (PCB),
polychlorobiphenyls (PCT) and apparatuses that contain them.
(BOE N° 206 of 28/08/99).
•Resolution of 9 of April of 2001, by the one that the publication
of the Agreement of the Counsel of Ministers is arranged, of 6
of April of 2001, by the one that the National Plan is approved
of Decontamination and Elimination of polychlorobiphenyls
(PCB), Polycloroterophenols (PCT) and apparatuses that
contain them (2001-2010). (BOE N° 93 of 18/04/01).
Law 10/1998 of 21 of April, of residues. http://www.boe.es/boe/dias/1998-04-22/seccion1.html#00000) Normative of reference: Directive 75/442/CEE, Directive 91/156/CEE, Regulation 259/93 of the Counsel. This Law is applicable to all kinds of residues, with exception of the emissions to the atmosphere, the radioactive residues and they poured to the water. It contemplates the residues in the prior phase to its generation, regulating the activities of every person that put in the generators products market of residues. With the purpose to achieve a strict application of the principle of "who contaminates pays", the Law associates the liability at the product, at the moment of its put in the market, the costs of the adequate management of the residues that generates said well and its accessories, such as the bottled or packing. It promotes the contribution among the Administration and the responsible for it put in the market of products that with its use are transformed into residues, by means of the creation of an adequate legal framework, with the subscription in agreement voluntary and of covenants of contribution. For the attainment of the objectives of reduction, reutilization, recycled and thermal energy recover, as well as to promote the technologies less contaminant in the elimination of residues, the Law foresees that the Public Administrations, in the environment of their respective competences, they can establish economic instruments of character and measured of incentive scheme. Likewise, norms upon the statement of soils are dictated contaminated and be to regulated the administrative responsibility derived from the of it non-fulfillment established in this Law, consider the infractiones as the sanctions that proceeds to impose like consequence of it.
<<Like any treatment technology, bioremediation is not without its limitations and disadvantages, however, the most important being the lack of well-documented field demonstrations that show the effectiveness of the technology and what, if any, are the long term effects of this treatment on water ground system. Some chemicals, e.g., highly chlorinated compounds and metals, are not readily amenable to biological degradation. In addition, for some chemicals, microbial degradation may lead to the production of more toxic or mobile substances than the parent thus, if bioremediation is applied without understanding of the microbial processes involved, it could lead to a worse situation than already exists in some cases.>>
THE END