Biological remediation

The options themselves invoke different controls and philosophies. The main techniques may be categorized according to whether they deal with the nutrients directly, or whether they interfere with the physical growth environment, or whether they invoke some form of biological remediation. 

Wild, JR USDA To develop an effective and complete biological remediation system capable of hydrolyzing organophosphorous neurotoxins from agricultural and chemical warfare munitions, contaminations, and wastes. 

Walton BT, Anderson TA. 1990. Microbial degradation of trichloroethylene in the rhizosphere Potential application to biological remediation of waste sites. Appl Environ Microbiol 56 1012-1016. 

U.S. EPA, Radionuclide Biological Remediation Resource Guide, Technical Report EPA-905-B-04-001, U.S. EPA, Washington, 2004. 

When all necessary nutrient supply systems are in balance and functioning properly, aerobic biological remediation can be relatively rapid. Gasoline components have been observed to have a half-life of days to months under well-controlled field conditions. Chemicals such as tetrachloroethylene that are best degraded under anaerobic conditions require significantly more time. Published half-lives for similar chlorinated solvents under field conditions are on the order of 300-day half-lives. Several computer programs are available that calculate the probable life expectancy of remedial projects. For best results, these programs require input of real field data. 

On the basis of the feasibility studies, an in situ technology was applied for the biological remediation of TNT and its transformation products. Microbiological transformation of TNT in the soil was stimulated by the addition of a carbon source and iron particles. The amount of additive was 51/m molasses and 5kg/m iron particles. Thus for the treatment of the whole 2,000m site, there was a requirement for lOm molasses and lOt iron. The addition of molasses and a subsequent mechanical tillage to a... 

T0395 Idaho Research Foundation, Inc., and White Shield, Inc., Simplot Anaerobic Biological Remediation (SABRE)... 

Hydrocarbon Environmental Recovery Systems bioremediation response advancement technologies (BRAT) are biological remediation products for treatment of organic contaminants in soil or water. According to the vendor this technology has been applied full scale at a number... 

The Simplot Anaerobic Biological Remediation (SABRE ) process is a patented, ex situ technology used to treat soils contaminated with nitroaromatic compounds. Researchers isolated a selection of anaerobic bacteria based on their ability to degrade nitroaromatic compounds with the total destruction of intermediate compounds by the completion of treatment. These bacteria are the basis of the SABRE process. 

This is an ex situ, slurry-phase, biological remediation technology that treats soils contaminated with organics, particularly polycyclic aromatic hydrocarbons (PAHs) with four or greater rings. 

According to the vendor, this commercially available technology can also enhance biological remediation. 

Laboratory studies confirmed that WRF can break down a wide variety of organic contaminants, some of which have historically been difficult for biological remediation using bacteria for degradation. 

It is also necessary to treat noncarbon-based pollutants. We mentioned nitrogen and phosphorus as possible targets for biological remediation. Nitrogen is present in wastewater streams as ammonia. Conventional methods convert the ammonia to nitrate. Under normal circumstances, the conversion is sufficient. However, excessive amounts of nitrates contribute to the eutrophication of lakes and ponds. In these cases, a second class of organism is used to convert the nitrates to nitrogen gas. 

The process produces no air emissions. Because this is an aqueous-based technology, neither NO, nor SO is produced. The delivery system is closed so no volatilization of toxic organic compounds occurs. The electron beam can be used efficiently and effectively as pretreatment for biological remediation. The electron beam can break complex organic compounds, making them suitable for microbiological degradation. 

Armstrong, D.E. and G. Chesters (1968). Adsorption catalyzed chemical hydrolysis of atrazine. Environ. Sci. Technol., 2 683-689. Arnold, S.M., W.J. Hickey, R.F. Harris, and R.E. Talaat (1996). Integrating chemical and biological remediation of atrazine and i-tnazine-containing pesticide wastes. Environ. Toxicol. Chem., 15 1255-1262. 

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