Bioremediation Flashcards
Bioremediation
Uses bacteria, fungi, green plants are there enzymes to return the environment all third by contaminants to its original conditions
It is a branch of biotechnology that employees the use of living organisms like microbes and bacteria in the removal of contaminants, pollutants and toxins from soil, water and other environments
Microorganisms maybe indigenous to contaminated area or maybe isolated from elsewhere and brought to the contaminated site
The process of bioremediation can be monitored indirectly by measuring oxidation reduction potential or redox in soil and groundwater, together with pH, temperature, oxygen content, electron acceptor/donor concentrations and concentration of breakdown products like carbon dioxide
Strategies of bioremediation (in-situ and ex-situ techniques)
In-situ techniques:
Involves the treatment of contaminated material at site
Bioventing (supply of air and nutrients through wells to contaminated soil to stimulate growth of indigenous bacteria)
Using simple hydrocarbons where contamination is Deep under surface
Biosparging (injection of air under pressure below water table to increase groundwater oxygen concentrations enhance trate for biological degradation of contaminants by naturally occurring bacteria)
Bio augmentation (microorganisms imported to contaminated site to enhance degradation process)
Ex-situ techniques:
Involves the removal of contaminated material to be treated elsewhere
Land farming (contaminated soil excavated and spread over prepared bed and periodically tilled until pollutants are degraded. The goal is distributed indigenous biodegradative microorganisms facilitate there aerobic degradation of contaminants).
Biopiles (hybrid of land farming and composting, engineered cells constructed as aerated composted piles).
Bio reactors (involves processing of contaminated solid material like soil sediment, sludge or water through engineered containment system).
Composting (TERI has developed a mixture of bacteria called oilzapper, the degrades pollutants of oil contaminated sites, leaving behind no harmful residues.)
Phyto remediation (use of plants to remove contaminants from soil and water)
Types of bioremediation
Phyto extraction/phyto accumulation: a process by which plants accumulate contaminants into their roots and above ground suits and leaves.
Phytotransformation or phytodegradation: the uptake of organic contaminants from soil sediments or water and their transformation to more a stable, less toxic and less mobile form.
Phytostabilization: a technique that plants reduce mobility and migration of contaminated soil.
Phyto degradation or rhizodegradation: it is The breakdown of contaminants through activity existing in rhizosphere due to the presence of proteins and enzymes produced by plants or by soul organisms, like bacteria, yeast, fungi.
Rhizofiltration: a water immediately and technique which involves the uptake of contaminants by plant roots. It is used to reduce contamination in natural wetlands and estuary areas.
Myco remediation: a form of bioremediation in which fungi is used to decontaminate an area
Myco filtration: using fungal mycelia to filter toxic waste and microorganisms from water in soil
Advantages and disadvantages of bioremediation
Advantages:
Useful for complete destruction of wide variety of contaminants
Complete destruction of target pollutants is possible
Less expensive
Environment friendly
Disadvantages:
Limited to compounds that are biodegradable
Not all compounds are susceptible to rapid and complete degradation
Biological processes highly specific
Difficult to extrapolate from bench and pilot scale studies to full scale field operation
Takes longer time then other treatment processes
