The effect of concentration and pH of poly-aluminum chloride on the treatment of industrial textile wastewater

Abstract The European Environment Agency reported that the textile sector is one of the most polluting industries, contributing 20% of clean water pollution from dyeing and finishing processes. This highlights the urgent need for improved wastewater treatment. Coagulation is a widely used primary treatment for industrial wastewater, especially in the textile industry. In this study, poly-aluminum chloride (PACl) was used as a coagulant, and the effects of varying coagulant concentrations (25, 50, 75, 100, and 125 ppm) and pH levels (6, 7, and 8) were evaluated using the Jar test. Water quality parameters such as pH, COD, color, hardness, conductivity, and turbidity were measured before and after treatment. The concentration of 25 ppm PACl at pH 7 showed optimal removal efficiency, achieving 76% COD, 55% color, 55% hardness, and 88% turbidity reduction. The results demonstrated that the treated wastewater complies with Standards A and B under the Malaysian Environmental Quality Regulations 2009, indicating the potential for PACl to be an effective coagulant for treating industrial textile wastewater.