Environmental Dynamics and Engineered Systems for the Degradation of Trichloroethylene: A Critical Review

Trichloroethylene (TCE) is found in all mediums of environment in varying concentrations. Over the past 25 years, many engineered systems have been devised for its complete and sustainable degradation. This study reviews the environmental factors that influence the TCE pollution in environment and its biological mineralization via engineered systems. Although at some polluted sites natural attenuation of TCE has been found to occur but generally the natural process is very slow. The use of nanoparticles and composites provides a comparatively novel approach for the treatment of TCE contaminated waters. Biological engineered systems have been found to degrade TCE on much faster rates and higher concentrations. To identify the appropriate microorganisms in any engineered system that can effectively provide a low-cost treatment option for TCE degradation is the pressing need at the moment. Adding a second distinct organic phase to the aqueous medium for degrading fast and high concentration of TCE is recommended. The organic phase, which do not mix with the aqueous phase and can be easily separated, discharged, and reuse, should be selected based on its insolubility, volatility, non-biodegradability by the selected microorganism and the cost of the overall engineered system. Biodegradation offers the potential of cost effective treatment of TCE, however, that engineered systems should effectively use the biodegradative metabolism that nature has evolved.