Treatability of diclofenac and triclosan solutions by catalytic and photocatalytic oxidation processes

Abstract

BACKGROUND

In recent years, advanced oxidation processes (AOP) have gained importance as highly effective methods in the treatment of organic substances with toxic and permanent properties. Diclofenac (DCF) and Triclosan (TCS) pollutants, which are from the endocrine disrupting chemicals (EDCs) that were encountered in various aquatic environments such as inlet and outlet waters of treatment plants, surface waters, drinking water, groundwater and sediments were reported in the literature. In this study, mineralisation of DCF and TCS pollutants, which were the EDCs, were investigated by AOPs. The applied processes were O₃, O₃/UV, O₃/ZnO, UV/ZnO, and O₃/UV/ZnO. The studies were carried out at two different initial concentrations (5 and 10 mg/L), at 5 ppm ozone dose, 2 × 8 W UVC light, 0.1 g ZnO, in the original pH, and 30 min reaction time.

RESULTS

The highest COD and TOC removal efficiencies were determined in O₃/UV/ZnO process as 82% COD, 71% TOC at 5 mg/L concentration for DCF pollutant and as 72% COD, 75% TOC at 10 mg/L concentration for TCS pollutant. For these process conditions, the ozone consumptions were determined 0.13 mgO₃/mgCOD_removed, 0.31 mgO₃/mgTOC_removed and 0.69 mgO₃/mgCOD_removed, 0.98 mgO₃/mgTOC_removed, respectively. The electrical energy per order values were found in the range of 12.33–20.88 kWh/m³ for O₃/UV/ZnO processes. Treatment costs of these processes were calculated in the range of 0.002 to 44.823 €/m³.

CONCLUSION

For the treatability of DCF and TCS pollutants, ozone-based advanced oxidation processes, especially O₃/UV/ZnO photocatalytic ozone oxidation process were determined as a feasible process. © 2024 Society of Chemical Industry (SCI).