Bioremediation

Bioremediation is a waste management technique that involves the use of organisms to remove or neutralize pollutants from a contaminated site. The naturally occurring organisms are able to break down hazardous substances into less toxic or non toxic substances. Bioremediation can be ex situ or in situ.  In situ bioremediation involves treating the contaminated material at the site, while ex situ involves the removal of the contaminated material to be treated elsewhere. The various techniques related to bioremediation are as follows:

Phytoremediation

• Phytoremediation is treatment using the plants that mitigate the environmental problem. Some plants such as mustard, hemp and pigweed (जंगली पालक in Hindi) have proven to be successful in Phytoremediation.

Bioleaching

• Bioleaching refers to extraction of metals from their ores through the use of living organisms. This is much cleaner than the traditional heap leaching. It is a sub-branch of biohydrometallurgy used to recover copper, zinc, lead, arsenic, antimony, nickel, molybdenum, gold, silver, cobalt etc.

Landfarming

• Landfarming is a bioremediation treatment process that is performed in the upper soil zone or in biotreatment cells. Contaminated soils, sediments, or sludges are incorporated into the soil surface and periodically turned over (tilled) to aerate the mixture. These land farming activities cultivate and enhance microbial degradation of hazardous compounds

Bioreactor

• A bioreactor may refer to any manufactured or engineered device or system that supports a biologically active environment. It is generally a vessel in which a chemical process is carried out which involves organisms or biochemically active substances derived from such organisms. This process can either be aerobic or anaerobic. These bioreactors are commonly cylindrical, ranging in size from litres to cubic metres, and are often made of stainless steel.
• A bioreactor may also refer to a device or system meant to grow cells or tissues in the context of cell culture. These devices are being developed for use in tissue engineering or biochemical engineering.

Bioaugmentation

• Bioaugmentation is the process of addition of bacterial cultures required to speed up the rate of degradation of a contaminant.
• Usually the steps involve studying the indigenous varieties present in the location to determine if biostimulation is possible. If the indigenous variety do not have the metabolic capability to perform the remediation process, exogenous varieties with such sophisticated pathways are introduced.
• Bioaugmentation is commonly used in municipal wastewater treatment to restart activated sludge bioreactors.

Rhizofiltration

• It’s a Phytoremediation technique which uses hydroponically cultivated plant roots to remediate contaminated water through absorption, concentration, and precipitation of pollutants. It also filters through water and dirt.

Bioremediation of Oil

Bioremediation uses the microorganisms or biological agents such as oil eating bacteria. There are three kinds of oil-consuming bacteria viz. Sulfate-reducing bacteria (SRB), Acid-producing bacteria are anaerobic and General aerobic bacteria (GAB).  Out of them, Sulfate-reducing bacteria (SRB) and acid-producing bacteria are anaerobic, while general aerobic bacteria (GAB) are aerobic