Energy sources bioremediation

The source of microorganisms and CP-degradation kinetics are key factors in on-site systems. Development of specific microbial cultures for bioremediation of CPs may involve pure and enrichment culture approaches. The approach of isolation and mass cultivation, followed by inoculation of the treatment system, has been applied to systems using, for example, Flavobacteria (O Reilly Crawford, 1989) and Rhodococci (Valo et al., 1989). The Flavobacterium-based processes sometimes involve addition of supplemental carbon and energy sources during CP treatment. 

Joshi, M. M. Lee, S. (1996). Effect of oxygetr amendments and soil pH on bioremediation of irrdustrially corttamirrated soils. Energy Sources, 18, 233 2. 

Reddy, K. R., Chinthamreddy, S., Saichek, R. E., and Cutright, T. J. (2003c). Nutrient amendment for the bioremediation of a chromium-contaminated soil be electrokinetics. Energy Sources 25(9), 931-943. 

Bioremediation in engineered systems can be used for removal of MTBE from groundwater. There are also naturally occurring microorganisms which have been shown to completely mineralise MTBE under aerobic conditions. Several pure strains that have been isolated and studied can mineralise MTBE. They do so by direct metabolism, whereby, MTBE is used as the sole carbon and energy source [15,21-25]. 

Chilingar GV, Loo WW, Khilyuk LF, Katz SA. (1997). Electro-bioremediation of soils contaminated with hydrocarbons and metals Progress report. Energy Sources 19 129-146. 

The primary metabolism of an organic compound uses a substrate as a source of carbon and energy. For the microorganism, this substrate serves as an electron donor, which results in the growth of the microbial cell. The application of co-metabolism for bioremediation of a xenobiotic is necessary because the compound cannot serve as a source of carbon and energy due to the nature of the molecular structure, which does not induce the required catabolic enzymes. Co-metabolism has been defined as the metabolism of a compound that does not serve as a source of carbon and energy or as an essential nutrient, and can be achieved only in the presence of a primary (enzyme-inducing) substrate. 

Bioremediation usually requires a procedure for stimulation of and maintaining the activity of microorganisms. For biodegradation to be successful, it is necessary to provide a continuous supply of a suitable electron acceptor (such as oxygen or nitrate), nutrients (nitrogen, phosphorus), and a carbon source for energy and cell material. The most commonly deficient components in the subsurface are eiectron acceptors and nutrients. 

Traditionally, wastewater has always been regarded as a source of pollution that requires treatment prior to disposal into the environment. Recently, wastewater has been increasingly viewed as a renewable resource of water, with nutrients and energy contained in organic matter as chemical bonds. This energy can potentially be converted directly into electricity in a MFC, be used to drive the production of a wide range of commodity chemicals, or be used for bioremediation purposes, including the removal of (recalcitrant) pollutants or for denitrification. 

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