UVC based advanced oxidation for decolourization and mineralization of calconcarboxylic acid in aqueous solution: Eco‐toxicological effect of post treated solutions and its remedy

Abstract

The present study reports two important aspects of wastewater treatment by UVC light (λ = 254 nm) in the presence of hydrogen peroxide (HP) and ammonium persulphate (APS) taking Calconcarboxylic acid (CCA) as a model pollutant. The first part deals with the effect of various operational parameters on the decolourization and mineralization of CCA. Most importantly, the eco‐toxicological effect of the treated solutions was examined on the basis of E. coli growth inhibition bioassay and the remedy for the same has been suggested in the second part. Although both oxidants show higher mineralization at pH 1, APS is preferred over HP for having higher mineralization, biodetoxification, and electrical energy efficiency. The presence of –COOH group in CCA has detrimental effect on its mineralization and biodetoxification, as well as on the electrical energy efficiency. Although a rise in mineralization at all pH is observed by the removal of the –COOH group, it is significant in alkaline media. Since treatment at pH 1 is not ideal for real scale applications, it is advisable to remove the –COOH group before treatment, so as to make treatment possible in alkaline media. Removal of –COOH group also leads to higher biodetoxification in a shorter treatment period.