Perchlorate contamination of drinking water sources in Kerala, South India, and its degradation using advanced chemical treatment

Perchlorate is an inorganic chemical reported to be resulting in widespread contamination of water bodies and even drinking water systems. The presence of perchlorate was identified in various drinking water sources (well, tap, borewell and bottled water) using liquid chromatography–mass spectrometry technique. The concentration of perchlorate in these samples is found in the order of bottled water ≫ well water > tap water > bore well water. Since most of the people in the study area depend upon this contaminated water for drinking purpose without any treatment, another important goal of this study was to propose suitable methods to remove or minimize the perchlorate concentration. This has been accomplished by advanced reduction processes (ARPs). Screening experiments including advanced oxidation processes such as UV photolysis, sonolysis, Fenton’s reaction in combination with reducing agents like sulfite, persulfate, ferrous iron at different pH and various concentrations were done. The experiments with ARPs are found to be degrading the perchlorate up to 32% in 5 h in Fenton-type reaction, and further experiments with modifications in the activation methods and reducing agents may give promising results for perchlorate degradation. Therefore, ARP technique offered more prominent results in terms of perchlorate removal, which can be easily extended in large-scale applications.