Bioremed.pptx

Bioremedian Process

1. BIOREMEDIATION Bioremediation refers to the process of using microorganisms to remove the environmental pollutants or prevent pollution. The removal of organic wastes by microbes for environmental clean-up is the essence of bioremediation. The other names used for bioremediation are biotreatment, bioreclamation and biorestoration. Xenobiotics broadly refer to the unnatural, foreign and synthetic chemicals such as pesticide, herbicide & other organic compounds. TYPES OF BIOREMEDIATION : 1. Biostimulation 2. Bioaugmentation 3. Intrinsic bioremediation

2. Bioaugmentation is the practice of adding cultured microorganisms into the subsurface for the purpose of biodegrading specific soil and groundwater contaminants. Biostimulation involves the modification of the environment to stimulate existing bacteria capable of bioremediation. This can be done by addition of various forms of rate limiting nutrients and electron acceptors, such as phosphorus, nitrogen, oxygen, or carbon (e.g. in the form of molasses). Bioventing is a process of stimulating the natural in situ biodegradation of contaminants in soil by providing air or oxygen to existing soil microorganisms. Bioventing uses low air flow rates to provide only enough oxygen to sustain microbial activity in the vadose zone.

3. BIOREMEDIATION IS A TRIPLE-CORNERS PROCESS Organisms Pollutants Environments Microorganisms Plants Enzymes Soil Water Air Organic Inorganic Solid Liquid Gas

4. REDOX CLEAN-UP REACTIONS Anaerobic or aerobic metabolism involve oxidation and reduction reactions or Redox reactions for detoxification. Oxygen could be reduced to water and oxidize organic compounds. Anaerobic reaction can use nitrate. In return, biomass is gained for bacterial or fungal growth. In many cases, combined efforts are needed, indigenous microbes found naturally in polluted sites are useful.

5. PSEUDOMONAS Genetically engineered bacteria ( Pseudomonas ) with plasmid producing enzymes to degrade octane and many different organic compounds from crude oil. A selected list of genetically engineered microorganisms GEMs XENOBIOTICS Pseudomonas putida Mono-and dichloro aromatic compounds P.diminuta Parathion P.oleovorans Alkane P.cepacia 2,4,5-Trichlorophenol Acinetobacter species 4-Chlorobenzene Alcaligenes species 2,4-Dichlorophenoxy acetic acid

6. USE OF FUNGI IN BIOREMEDIATION Candida can degrade formaldehyde. Gibberella can degrade cyanide. Slurry-phase bioremediation is useful too but only for small amounts of contaminated soil. Composting can be used to degrade household wastes. White rot fungi can degrade organic pollutants in soil and effluent and decolorize kraft black liquor, e.g. Phanerochaete chrysosporium can produce aromatic mixtures with its lignolytic system. Pentachlorophenol, dichlorodiphenyltrichloroethane (e.g. DDT), even TNT (trinitrotoluene) can be degraded by white rot fungi. WHITE ROT FUNGI

7. ENVIRONMENTAL CLEAN-UP PROCESS The basis of removal and transportation of wastes for treatment, basically there are two methods . 1.Insitu bioremediation 2.Ex situ bioremediation INSITU BIOREMEDIATION : * It involves direct approach for the microbial degradation of xenobiotics at the sites of pollution (soil, ground water). * It has been successfully applied for clean-up oil spillages, beaches etc . * There are 2 types of insitu bioremediation , ‡ Intrinsic bioremediation ‡ Engineered bioremediation

8. EXSITU BIOREMEDIATION * The waste or toxic materials can be collected from the polluted sites and the bioremediation with the requisite microorganisms can be carried out at designed places. METABOLIC EFFECT OF MO’S ON XENOBIOTICS: ¤ Detoxification ¤ Activation ¤ Degradation ¤ Conjugation TYPES OF REACTIONS IN BIOREMEDIATION : » Aerobic bioremediation » Anaerobic bioremediation » Sequential bioremediation

9. BIOREMEDIATION OF HYDROCARBONS Petroleum and its products are hydrocarbons. Oil constitute a variety of hydrocarbons ( xylanes, naphthalenes, octane's, camphor etc,). The pollutants can be degraded by a consortium of microorganisms, e.g Pseudomoas, Corynebacterium, Arthrobacter, Mycobacterium and Nocardia . Genetically engineered bacterial strains are used to enhance bioremediation. In 1979, Anand Mohan Chakrabarty - obtained a strain of Pseudomonas putida that contained the XYL and NAH plasmid as well as a hybrid plasmid derived by recombinating parts of CAM and OCT. In 1990, the USA Govt allowed him to use this superbug for cleaning up of an oil spill in water of State of Texas. It was produced on a large scale in laboratory, mixed with straw and dried.

10. Sewage from cities Industrial effluents Oil slick Pollution from warships Military activities MARINE POLLUTION

11. MARINE POLLUTION

12. Oil spill 11 million gallon oil spill from the supertanker EXXON VALDEZ - ALASKA in March-1989 .

13. Landfarming (Ex-Situ remediation)

14. What is Landfarming ? Landfarming , also known as land treatment or land application, is an above-ground remediation technology for soils containing hydrocarbon contaminant through biodegradation. As with other biological treatments, under proper conditions, landfarming can transform contaminants into non-hazardous substances. Contaminated Soil Treatment

15. Bioremediation Technology It is a natural processes that cleans up harmful chemicals in the environment. Microscopic “bugs” or microbes that live in soil and groundwater like to eat certain harmful chemicals , such as those found in oil spills. When microbes completely digest these chemicals, they change them into water and harmless gases such as carbon dioxide .

16. Application This technology usually involves spreading contaminated soils in a thin layer on the ground surface and stimulating aerobic microbial activity within the soils through aeration and/or the addition of minerals, nutrients, and moisture. Each strip shall be clearly marked on a board, by the Contractor, with the following information: : Date of spreading Treatment applied Each strip is recorded by marking the date of spreading & treatment applied.

17. Operation Principles The effectiveness of landfarming depends on parameters that may be grouped into four categories: soil characteristics constituent characteristics climatic conditions Soil texture which may affects moisture content, and bulk density of the soil. For example , soils which tend to clump together (such as clays) are difficult to aerate and result in low oxygen concentrations . It is also difficult to uniformly distribute nutrients throughout these soils. Periodic soil samples are tested to check on how breakdown of the contaminants is progressing.

18. Soil Condition Soil conditions are often controlled to optimize the rate of contaminant degradation. Conditions normally controlled include: Moisture content (usually by irrigation or spraying). Aeration (b y frequently tilling the soil, the soil is mixed and aerated). pH (buffered near neutral pH by adding crushed limestone or agricultural lime). Other adjustment (e.g., Soil bulking agents, nutrients, etc.). Tilling of strip as part of landfarming Watering of strip as part of landfarming

19. SOIL SHREDDING

20. System Design Landfarm Construction includes: site preparation (grubbing, clearing and grading); Liners (if necessary); Leachate collection and treatment systems; Soil pretreatment methods ( e.g. , shredding, blending and pH control); To support bacterial growth, the soil pH should be within the 6 to 8 range, with a value of about 7 (neutral) being optimal. Soil microorganisms require moisture for proper growth. Excessive soil moisture restricts the movement of air through the subsurface thereby reducing the availability of oxygen. In general, the soil should be moist but not wet or dripping wet.

21. Advantages Simple to design and implement. Short treatment period (usually 6-9 months under optimal conditions). Effective organic constituents with slow biodegradation rates. Treated soil healthy enough to grow plants

22. Disadvantages May not be affective for high constituents concentration of hydrocarbon (greater than 50,000ppm total petroleum hydrocarbon). Requires a large land area for treatment. May require bottom liner if leaching from the landfarm is a concern. Dust and vapour generation during landfarm aeration may pose air quality concerns. Dust generated during tilling

23. Phytoremediation Use of green plants and other autotrophic organisms to clean up and manage hazardous and other wastes Includes bioremediation by heterotrophic bacteria when plants provide carbon, nutrients, or habitat – rhizodegradation Phytoextraction – accumulates metals in above ground tissues for harvest Phytodegradation or transformation Phytocontainment and stabilization Phytovolatilization and other types

24. Phytoremediation is use of plants for accumulation , removal or conversion of pollutants. PHYTOREMEDIATION Phytoremediation Phytostabilization Phytotransformation Phytoextraction Phytovolatilization Phytostimulation

25. TABLES

26. Approximately 400 plant species have been classified as hyperaccumulators of heavy metals, such as grasses, sunflower, corn, hemp, flax, alfalfa, tobacco, willow, Indian mustard, poplar, water hyacinth, etc.

27. The root exudates of these plants play an important role in phytoremediation as it activate the surrounded microorganisms. Genetic engineering are used as in case of BT protein or insect pheromones producing plants to reduce the use of pesticides.

28. PHYTO-REMEDIATION Effective and low cost , environmental friendly. Soil clean up of heavy metals and organic compounds. Pollutants are absorbed in roots, thus plants removed could be disposed or burned. Sunflower plants were used to remove cesium and strontium from ponds at the Chernobyl nuclear power plant. Transgenic plants with exogenous metallothionein (a metal binding protein) used to remove metals .

29. Metals bioremediation mechanisms Solubilization (Bioleaching) Complexation (Bioaccumulation) (Biosorption) Metal immobilization Precipitation - H 2 S producing bacteria - Siderophores. - Metal reduction. - Exopolysaccharide. - Lipoproteins. - Organic acids. - Siderophores. - Root exudates.

30. Industries plastics, textiles, microelectronics, wood preservatives, refineries etc. Agrochemicals Excessive use of fertilizers and pesticides etc. Waste disposal sewage sludge leach ate from landfill, fly ash disposal etc. Mining activities smelting, river dredging, mine spoils and tailings, metal industries etc. Atmospheric deposition urban refuse disposal, hydrometallurgical industries, automobile exhausts, fossil fuel combustion etc . Heavy metals sources in the environmental SOURCES OF HEAVY METALS IN THE ENVIRONMET

31. The biosurfactants are chemical compounds characterized by hydrophobic and hydrophilic (non-polar and polar) regions in one molecule ( amphipathic molecules). Biosurfactants from bacteria, cyanobacteria, fungi and yeast are classified into: 1 . Glycolipids. 2. Lipopeptides. 3. Phospholipids. 4. Glycoproteins. 5. Polymeric biosurfactants. BIOSURFACTANTS PRODUCING GEM A genetically engineered Pseudomonas aeruginosa. This new strain can produce a glycolipid emulsifier. It can reduce the surface tension of an oil water interface. The reduced interfacial tension promotes biodegradation of oils. BIOSURFACTANTS

32. BIOREMEDIATION OF INDUSTRIAL WASTES A variety of pollutants are discharged in the environment from a large no of industries & mills. 1. Bioremediation of Dyes 2. Bioremediation in the paper and pulp industry BIOREMEDIATION OF CONTAMINATED SOILS & WASTE LANDS SLURRY-PHASE BIOREACTOR LANDFARMING-BIOREMEDIATION

33. PREVENTION AND CONTROL OF POLLUTION These activities are supported by a set of legislative and regulatory promotional measures such as Policy Statement on Abatement of Pollution, 1992; and the National Environment Policy, 2006. The major actions on Abatement of Pollution and Environmental Cleanup are as follows: Clean Technology (CT), Control of Pollution (CP), Environment Education (EE), Environmental Impact Assessment (IA), Environmental Information (EI), Environmental Information System (ENVIS), Environment Research (RE), Forest Protection (FPR), Hazardous Substances Management (HSM) , Climate Change(CC) , Clean Development Mechanism (CDM).

34. There is an immediate necessity for initiating an “All India Coordinated project on Bioremediation of the Contaminated Sites” involving premier institutions in this field for conducting large scale demonstration projects. Further, various departmental agencies and related ministries in India may plan a joint action plan to launch bioremediation from Lab-Pilot –Field scale projects at specific sites Possible All India coordinated bioremediation demonstration projects at specifi c sites

35. BIOREMEDIATION FROM LAB-PILOT –FIELD SCALE

36. Bioremediation is a natural process and is therefore perceived by the public. B ioremediation is useful for the complete destruction of a wide variety of contaminants. Instead of transferring contaminants from one environmental medium to another, for example, from land to water or air, the complete destruction of target pollutants is possible. ADVANTAGES AND DISAD VANTAGES ADVANTAGES OF BIOREMEDIATION Bioremediation can often be carried out on site, often without causing a major disruption of normal activities. Bioremediation can prove less expensive than other technologies that are used for cleanup of hazardous waste.

37. DISADVANTAGES OF BIOREMEDIATION Bioremediation is limited to those compounds that are biodegradable. Not all compounds are susceptible to rapid and complete degradation. There are some concerns that the products of biodegradation may be more persistent or toxic than the parent compound. Biological processes are often highly specific. microbial populations, suitable environmental growth conditions, and appropriate levels of nutrients and contaminants. It is difficult to extrapolate (deduce) from bench and pilot-scale studies to fullscale field operations. Bio r e mediation often takes longer than other treat ment options.

38. Inorganic metal contaminants Organic contaminants Radioactive contaminants Brake fern Poplar tree Indian mustard Oil spill Groundwater Soil Polluted groundwater in Polluted leachate Decontaminated water out Landfill Willow tree Phytoextraction Roots of plants can absorb toxic metals such as lead, arsenic, and others and store them in their leaves. Plants can then be recycled or harvested and incinerated. Phytodegradation Plants can absorb toxic organic chemicals and break them down into less harmful compounds which are stored or released into the air. Phytostabilization Plants can absorb chemicals and keep them from reaching groundwater or nearby surface water. Rhizofiltration Roots of plants with dangling roots can absorb pollutants such as radioactive strontium-90 and cesium-137 and various organic chemicals. Sunflower Phytoremediation Groundwater Soil

39. Trade-Offs Phytoremediation Advantages Disadvantages Easy to establish Inexpensive Can reduce material dumped into land fills Produces little air pollution compared to incineration Low energy use Slow (can take several growing seasons) Effective only at depth plant roots can reach Some toxic organic chemicals may evaporate from plant leaves Some plants can become toxic to animals Tradeoffs of Phytoremediation