1 / 50

What is bioremediation?

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

duena
Télécharger la présentation

What is bioremediation?

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BIOREMEDIATION OF SOILS AND GROUNDWATER CONTAMINATED WITH PHENOLICS, CHLORINATED PHENOLS, PCP AND CREOSOTES

  2. 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

  3. 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.

  4. How Does Bioremediation Work? Uses naturally occurring microorganisms to break down hazardous substances into less toxic or nontoxic substances.

  5. 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.

  6. Bioremediation Of Groundwater • In-situ-Almost invariably undergoes in situ bioremediation.

  7. 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.

  8. Factors affecting successful bioremediation? • Site Characterisation • Microbiological Characterisation • Environmental Factors

  9. Techniques of bioremediation. In Situ Bioremediation of Soil • (1) Bioventing • (2) Injection of Hydrogen Peroxide

  10. Techniques of bioremediation. • In Situ Bioremediation of Groundwater • Activated Sludge Reactors

  11. Techniques of bioremediation. • Ex situ Bioremediation of Soil • Slurry Reactors • Landfarming

  12. 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.

  13. What is creosote used for? • Wood treatment • Restricted-use pesticide • Animal and bird repellant • Insecticide • Fungicide • Animal dip .

  14. 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

  15. Cresote’s fate in the environment? The factors affecting cresoste’s fate It’s physical and chemical properties. The KOW of creosote’s components

  16. Creosote’s toxicity • carcinogenic • mutagenic • teratogenic

  17. What are phenols? Phenols are a large group of naturally occuring ,chemically diverse compounds . phenol Phenol Phenol Phenol Phenol is a colorless or white solid when it is pure; however, it is usually sold and used as a liquid. Phenolics are characterised by the presence of an aromatic ring and one or two hydroxyl groups

  18. What are phenolics used for? • Phenolic disinfectants • Phenolic resins

  19. 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

  20. 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 )

  21. Sources of chlorophenols to the environment • Forest industry • Pulp bleacheries • Biocides • Industrial Waste streams • Chlorine treated water • Microbial breakdown herbicides

  22. 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

  23. 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”.

  24. 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

  25. 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

  26. ANAEROBIC BIOREMEDIATION • ALTERNATIVE ELECTRON ACCEPTORS • REDUCTIVE DECHLORINATION • PHENOL AS FINAL END PRODUCT OR CONVERSION TO METHANE AND CO2

  27. 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

  28. Figure 1.4 White Rot Fungus: Trametes versicolor

  29. 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

  30. ISOLATION OF MICROBIAL DEGRADERS OF CREOSOTE Figure 1.5 White rot Fungus: Bjerkandera adusta

  31. ENVIRONMENTAL FACTORS AFFECTING BIODEGRADATION The main factors influencing in situ contaminant bioremediation include: Ø      oxygen Ø      nutrients Ø      moisture content Ø      pH Ø      redox potential Ø      temperature Ø      bioavailability These factors can be manipulated in order to optimize the correct conditions.

  32. Why Bioremediation? ADVANTAGES AND DISADVANTAGES

  33. 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.

  34. 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.

  35. 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

  36. BARRIERS TO COMMERCIALIZATION 1.RESEARCH BARRIERS 2.TECHNICAL BARRIERS 3.ECONOMIC BARRIERS 4.REGULATORY BARRIERS

  37. 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 …….)

  38. 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.

  39. 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.

  40. 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

  41. SUMARY OF LEGISLATION: • EUROPEAN LEGISLATION

  42. 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.

  43. EUROPEAN LEGISLATION • 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).

  44. ·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).

  45. ·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).

  46. ·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.

  47. <<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.>>

  48. THE END

More Related