BIOREMEDIATION OF ENVIRONMENTAL POLLUTANTS

presented by, Rituparna Addy, Pranab Roy

Department of Biotechnology

Haldia Institute of Technology

Soil vapor extraction Air sparging Bioremediation Thermal desorption Soil washing Chemical

dehalogenation Soil extraction In situ soil flushing

Technologies used to remove contaminants from environment

Uses microorganisms, fungi, green plants to break down harmful chemicals and pollutants to less harmful compounds.

Biological method to clean up oil spills & pollution from soil, groundwater, surface water and air.

Relies largely on the enzymatic activities of microbes as they have extraordinary metabolic diversity to catalyze the destruction of pollutants.

INTRODUCTION

Microbes

Degradationproducts

CO2 + H2ONutrients

Contaminants

Industrial spills and leaks Surface impoundments Storage tanks and pipes Landfills Burial areas and dumps BTEX- Benzene, Toluene,

Ethyl-benzene, Xylene Herbicides and pesticides Nitroaromatic explosives

and plasticizers Nuclear wastes Agricultural chemical

wastes( Triazine, DDT)

Inorganics (Uranium, sulfur, sulfuric acid)

Explosives (RDX, TNT) Polyaromatic

hydrocarbons (creosote) Chlorinated hydrocarbons

(Trichlorethylene, PCBs, pentachlorophenol)

Petroleum hydrocarbons (Gas, deisel)

Heavy metals (Cd, Cu, Pb)

PCB (Polychlorinated biphenyls)

Sources of Contamination

Natural Pure cultures (Flavobacterium sp.,

Pseudomonas sp.) Mixed cultures (Consortia, Methane-

utilizing bacteria) Genetically engineered

microorganisms Deinococcus radiodurans

(resistant to high levels of radiation)

TYPES OF ORGANISMS

Ambient environmental conditions Promote growth of desirable organisms Composition of the microbial community pH & Temperature Nutrients & molecular oxygen Nature and amount of pollution present Primary, Secondary, Co-metabolic Substrates The possible catabolic pathways of metabolism of

micro-organisms

FACTORS

1990:treatment of organics derived from humanor animal wastes 1950:wastewater treatment to industrial wastes 1960:Bioremediation was devised by George M

Robinson bioremediation of synthetic chemicals in wastewaters 1970:application in hydrocarbon contamination 1990:the development of barrier approaches 2000:in situ bioremediation; source zone reduction;

bio-augmentation

HISTORY

RESEARCH PERIOD(1970-1980)

HONEYMOO

N PERIO

D(1989

-1991)

ESTABLISHMENT PERIOD(1992-

PRESENT)

Prof. Ananda Mohan Chakraborty et al. (1980) developed and patented a “superbug” that degraded petroleum (camphor, octane, xylene, and naphthalene) by plasmid transfers.

transformed Pseudomonas putida with plasmids derived from four different bacteria involved in hydrocarbon degradation.

BIOREMEDIATION

PETROLEUM HYDROCARBONS

PHYTOREMEDIATION

FUNGI

BIOFILMSBIOLEACHIN

G

Bio-augmentation: Introduction of a group of natural microbial strains or a genetically engineered variant to the reaction chamber.

Bio-stimulation: modification of the environment to stimulate existing microorganisms capable of bioremediation.

Land farming: Simple and inexpensive, currently accepted method.

PETROLEUM HYDROCARBONS

Structured community of bacterial, algal, or other types of cells enclosed in a self-produced polymeric matrix.

Waste can accumulate to toxic levels inside biofilm.

Treatment of recalcitrant compounds

Bacterial chemotaxis

Metal recovery purpose Micro-organisms produce

acids from reduced sulfur compounds

Acids then solubilize the desired metals

Leptospirillum, Thiobacillus thiooxidans

Leptospirillum ferrooxidans

BIOFILMS BIOLEACHING

Use of plants to clean up pollutants

Plants work with soil organisms to transform contaminants into harmless compounds

Phytoextraction, Phytotransformation, Phytostabilization, Phytovolatilization, Phytostimulation, Rhizofiltration.

PHYTOREMEDIATION

ADVANTAGESTolerate toxins,Extensive root system,Adapted to different ecosystems

Pteris vittata

Thlaspi caerulescens Alyssum bertolonii and Berkheya coddii

Alyssum serpyllifolium

Brassica juncea

Liriodendron tulipifera

Cannabis sativa Eichhornia crassipes

Thlaspi montanum

PHYTOREMEDIATION PLANTS

Mycoremediation Decomposition by

fungal mycelium Enzymes & acids

degrade various pollutants

Filamentous fungi. Oyster mushrooms,

 Wood-decay fungi, Aspergillus

FUNGI

IN-SITU BIOREMEDIATION On-site bioremediation Cheapest and most efficient Bioventing, Bio-augmentation, Biosparging Site disturbance is minimized Types:Intrinsic bioremediation & accelerated bioremediation

• Uses micro-organisms already present in the environment

• No human intervention

• Substrate or nutrients are added for growth

• Indigenous micro-organisms

Contaminated land are taken out of the area to be cleaned up by the organisms

Expensive process Causes damage to the area Landfarming, Composting, Bioreactors

EX-SITU BIOREMEDIATION

IDENTIFICATION OF BIODEGRADING ORGANISMS

ISOLATION OF BACTERIA

MINIMAL MEDIA CONTAINING POLLUTANTS

SCREENING

CHARACTERIZATION

AMPLIFICATION(16S rRNA)

PCR TECHNIQUE(16 S r DNA)

NCBI DATABASE

PHYLOGENETIC TREE CONSTRUCTION

Simple, highly specific, less expensive process Complete degradation and clean up of a wide variety

of contaminants Uses a natural process & can be carried out on-site Good public acceptance The groundwater and soil can be treated at the same

time by using in-situ bioremediation.

DISADVANTAGES Limited to bio-degradable compounds Products may be more persistent or toxic than the

parent compound Factors must be maintained as it is highly specific Not instantaneous May have inhibitors present.

ADVANTAGES

Recovery of a contaminated medium by using living organisms. Approach to enhance the degrading capability. Application in all types of contaminated fields. Effective process. Genetic engineered micro-organisms. Eco-friendly technology.

CONCLUSION

Chakrabarty, AM; Mylroie, JR; Friello, DA; Vacca, JG (1975). "Transformation of Pseudomonas putida and Escherichia coli with plasmid-linked drug-resistance factor DNA". Proceedings of the National Academy of Sciences of the United States of America 72 (9): 3647–51.

Del‘Arco, JP, de, França FP (2001), ―”Influence of oil contamination levels on hydrocarbon biodegradation in sandy sediment‖, Env. Pollut”. 110: pp. 515-519.

Brar SK, Verma M, Surampalli RY, MisraK, Tyagi RD, Meunier N and Blais JF, “Bioremediation of hazardous wastes: are view‖, Pract Periodical Hazard, Toxic Radioactive Waste Management”. 10:59-72, 2006.

REFERENCES

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