Degradation of pesticides in groundwater by advanced oxidation processes

Abstract

Safe and clean drinking water is a right of every human being on this earth. The industrial and agricultural activities have made this precious element unfit for human consumption. Major reasons for water pollution being discharge from different industries and indiscriminate use of pesticide in agricultural fields. Pesticide pollution of surface water and groundwater has been recognized as a major problem in many developing countries because of the persistence of pollutants in aquatic environments. One of the consequences of indiscriminate use of pesticide is the adverse health impact on society in general and vulnerable population like children in particular. Humans are exposed to pesticides found in environmental media (soil, water, air and food) by different routes of exposure such as inhalation, ingestion and dermal contact. Some of the well-known health effects of pesticide exposure include acute poisoning, cancer, neurological effects and reproductive and developmental effects. Conventional treatment technologies like physico-chemical, biological treatment, air stripping and carbon absorption have limitations as they merely change the phase of the pollutant. Biological methods are incapable especially where the organic pollutants are bio-recalcitrant in nature like pesticides. Thus, incapability of conventional and biological treatment methods for removal of pesticides has substantially increased the concern. Lack of knowledge, repeated and overdose of pesticides has irreversibly damaged our land, air and water bodies, thus has invited many researchers for novel treatment options. In recent past, advanced oxidation processes (AOPs) have proved their worth for the remediation of contaminated wastewaters containing non- biodegradable organic pollutants. The main mechanism of AOPs is the generation of highly reactive free radicals like hydroxyl radicals (OH ) which are effective in destroying organic chemicals because of their high reactive electrophilic behaviour.