Bioremediation is the biological transformation of organic compounds.It can lead to the complete mineralization of the compounds or to other organic products depending on the physico-chemical conditions of the medium.
Under oxidative condition, micro organisms can mineralize many organic compounds to CO2, water, salts are produced.
Oxidative conditions are guarantied by the presence of oxygen. Under reducing conditions, most organic compounds would be fermented with the production of methane and CO2. Chlorinated products can be dechlorinated, yielding to less chlorinated product and eventually to a completely dechlorinated product.
Applications
There are 2 kinds of Bioremediation: enhanced aerobic and enhanced anaerobic bioremediation.
Enhanced aerobic bioremediation technologies are used to accelerate naturally occurring in-situ bioremediation of:
Petroleum hydrocarbons, as BETX, MTBE, Light fuel oils, Heavy fuel oils, non halogenated volatile solvents, Phenols, PAHs (Rings<3), High explosives, low chlorinated products like dichloromethane, 12-dichloroethane, dichloroethene, vinyl chloride, semi volatile halogenated compounds.
Some fuel oxygenates such as methyl tertiary-butyl ether (MTBE),
Enhanced anaerobic bioremediation technologies are used to accelerate naturally occuring is-situ bioremediation of perchloroethene, trichloroethene, dichloroethene, tetrachloroethane, vinyl chloride.
Enhanced Aerobic Bioremediation
By providing oxygen into the subsoil, the biodegradation activity of aerobic bacteria is enhanced. It results in an enhanced aerobic biodegradation of many organic compounds.
In the presence of sufficient oxygen (aerobic conditions), and other nutrient elements, microorganisms will ultimately convert many organic contaminants to carbon dioxide, water, and microbial cell mass.
Technologies
Enhanced aerobic bioremediation technologies can be used to reduce contaminants in the unsaturated zone, the saturated zone, or both.
Technologies include:Biosparging, Bioventing, Injection of IXPER® : calcium or magnesium, peroxides suspensions, Pure oxygen injection,Hydrogen peroxide infiltration,Ozone injection.
Enhanced Anaerobic Bioremediation
Where reductive conditions are needed for the dechlorination of chlorinated products like trichloroethene, perchloroethene, an easily metabolised carbon source is injected in the soil. It will stimulate the micro organisms activity whereby scavenging any oxygen present. The resulting strongly reduced conditions are favourable to the development of the dechlorinating activity.
Technologies
Technologies include injection into the soil of: Lactose, lactic acid, lactates, molasses and dairy industry by products.
