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