DOI: https://doi.org/10.55373/mjchem.v27i6.41

Keywords: Photolysis, photocatalysis; Advance Oxidation Process (AOPs); linear alkyl benzene sulfonate (LAS) surfactant; wastewater treatment

Abstract

Detergents and surfactants widely used in households and industries have become persistent water pollutants. Their harmful environmental impact highlights the urgent need for effective degradation strategies. This study investigates the photolytic and photocatalytic degradation of linear alkyl benzene sulfonate (LAS) and detergent solutions under various experimental conditions using Advanced Oxidation Processes (AOPs). Titanium dioxide (TiO₂) served as the photocatalyst, while light sources included a solar lamp and ultraviolet radiation (UV-A, UV-B, and UV-C). A comparative study of photolysis and photocatalysis performance was performed using varying light sources, initial pollutant concentrations, and solution pH, while photocatalysis was further assessed by adjusting the catalyst dosage. The optimal catalyst dosage of 0.15 g/L, initial concentrations of 5 ppm for LAS and 50 ppm for the detergent, an acidic pH of 4, and UV-C light, resulted in faster degradation compared to other tested conditions. Under these optimized conditions, LAS and detergent showed photolytic degradation of 65.56 % and 67.52 %, respectively, which increased to 93.33 % and 91.78 % under photocatalytic conditions. Analysis of biochemical oxygen demand (BOD) and chemical oxygen demand (COD) values provided further confirmation of degradation, indicating a substantial decrease in both parameters for the LAS and detergent solutions during the treatment process. A comparative analysis was carried out on LAS, detergent, and actual laundry wastewater to assess variations in their degradation patterns across diverse environmental conditions. The novelty of this study lies in the application of TiO₂ for the degradation of LAS and detergent solutions, which achieved significantly higher removal efficiencies. Further optimization of parameters could achieve maximum pollutant removal, and offer a practical solution for wastewater treatment.