Metal ion-catalyzed mineralization and biodetoxification studies of Calconcarboxylic acid in aqueous solution: effect of –COOH group

Abstract

A B S T R A C TMineralization and biodetoxification studies of Calconcarboxylic acid (CCA), an azo dye, were undertaken by metal ion-catalyzed oxidation processes, viz. Fenton and Fenton-like processes and the effect of presence of -COOH group thereon were established. The metal ions used were Fe 2+ and Ag + and the oxidants used were hydrogen peroxide (HP) and ammonium persulfate (APS). For a given oxidant, Fe 2+ is found to be the most suitable catalyst and among the oxidants, APS proves to be most suitable one. As all the systems yield maximum mineralization at pH 1, Fe 2+ /APS at pH 1 is the most suitable system. It is observed that mineralization is favored by Fe 2+ /HP process due to the presence of -COOH group in CCA and by Fe 2+ /APS process in its absence. Removal of -COOH group causes a shift in optimum pH, for Fenton process, to 3 accompanied by a corresponding drop in mineralization from 70.6 to 35.6% and an increase from 73.2 to 91.1% in Fe 2+ /APS system. Bioassay experiment reveals that the treated solutions are ≥50% biotoxic than the untreated dye, which could be reduced to 22.7 and 26.7% in Fe 2+ /APS and Ag + /APS systems, respectively, when the -COOH group is removed.

Simultaneous Removal of Calconcarboxylic Acid, NH4+ and PO43− from Pharmaceutical Effluent Using Iron Oxide-Biochar Nanocomposite Loaded with Pseudomonas putida

“…CCA has acute health effects such as irritation or damage of the human eye, skin inflammation, and lung damage in case of inhalation, while long-term exposure may lead to pneumoconiosis and bladder cancer. In addition, there are negative influences on the biotic environment components by azo dyes, such as the carcinogenic effect on living marine organisms and the inhibition of photosynthesis in plants [2]. Thus, azo dyes in industrial wastewater must be treated properly before it is released to the environment.…”