Evaluating the photocatalytic degradation efficacy of 2,4,6-trichlorophenol: performance evaluation and influencing factors

Abstract

Chlorophenols are organic compounds that have garnered considerable attention in recent years because of their prevalent occurrence in the environment and associated harmful effects on ecosystems and human health. The current work investigated the photocatalytic oxidation of 2,4,6-trichlorophenol as a potential treatment option. The effects of different process-conditioning parameters were studied. Analytical-grade commercially available TiO2 reported 80% degradation, whereas nano-grade TiO2 resulted in complete removal in the same time duration. Furthermore, the study assessed the use of Degussa P-25 nano-TiO2 at varying doses for the optimization of treatment. Under the optimal dose of 250 mg/L of nano-TiO2, the complete removal of 2,4,6-trichlorophenol was observed within 210 min of the reaction period. The addition of H2O2 to further increase the rates of treatment did not yield any benefit. Under solar irradiation, almost 95% degradation of 2,4,6-trichlorophenol was observed in 315 min at an optimized photocatalyst dose. Moreover, the comparison of the operational cost of UV-photocatalysis (UV/nano-TiO2), photocatalysis with H2O2 (UV/nano-TiO2/H2O2) and solar-photocatalysis revealed costs of US$0.27 per litre, US$0.30 per litre and US$0.16 per litre, respectively, during the experimentation, thus making solar-photocatalysis the best option.