Photocatalytic degradation of multi-organo-sulfur industrial wastewater using TiO2 produced from modified sulfate process

Abstract

This study focuses on the photocatalytic degradation of industrial wastewater containing organic pollutants using modified sulfate process derived-titanium dioxide (mspd-TiO2). The mspd-TiO2 is duly characterized and compared with commercially available Degussa P-25 TiO2. The industrial effluent is assayed for pollutants and is found to have high sulfur content (S = 11.37 ± 0.15 %) and the presence of organic compounds. The powder studied, mspd-TiO2, demonstrated a desirable efficiency in treating the industrial wastewater, as the COD value decreased from 7680 mg/l to 320 mg/l after degradation. Sulfur Black and Acid Orange 7, both of which are in the industrial effluent, are degraded using mspd-TiO2. The efficiency of mspd-TiO2 in degrading the pollutants is 80 ± 3 % for Sulfur Black and 72 ± 3 % for Acid Orange7 within 2 h. This is achieved at a loading of 150 g/l TiO2 at pH 5 (k = 0.0125 ± 0.002 min−1). Results indicate that the catalyst remained structurally stable after degradation. The mspd-TiO2 exhibited decreased activity during the reusability test due to loss of activation sites, particle aggregation, and mass loss. Overall, significant degradation of the pollutants is observed. This study demonstrates the potential of mspd-TiO2 for efficient and cost-effective treatment of industrial wastewater containing complex sulfur-containing organic pollutants.