Perchlorate Removal Methods and Effect of Environmental Factors on its Biodegradation

There is a persistent emergence of human health and ecological assessment issues associated with perchlorate (ClO4-) and it is observed that even at extremely low concentration causes serious health implications on human being. It is used in rocket fuels, fireworks, explosives and other applications were an energetic oxidant is required. The existence of ClO4as a contaminant in effluent water, ground water and drinking water is of particular concern and its unique physical and chemical properties makes challenging to treat. Hence there is an urge to develop technologies for perchlorate remediation in contaminated water or contaminated sites. This review deals with ClO4removal methods and various environmental factors which affects on its degradation. This also summarizes the possible methods for the efficient removal of ClO4and their feasibility study. The various bench scale studies on the removal of ClO4in water and the effect of pH, temperature, salinity, dissolved oxygen (DO), acetate, nitrate, nitrite, molybdenum, sulphate, iron and rhenium on microbial degradation of ClO4are also discussed. Improper disposal and usage of inefficient treatment techniques results in the bioaccumulation of ClO4to the environment. Microbial mediated treatment is the most cost effective method in which the initial biomass level, influent perchlorate/acetate ratio, pH, presence of nitrate/nitrite, presence of oxygen scavengers like sulphide, salinity, presence of dissolved oxygen are the significant parameters on its degradation. Nevertheless, there is a need of integrated treatment approach that would create a passive remediation system at the contaminated site itself.