Journal of Applied Chemical Science International

Industrial wastewater containing synthetic dyes such as RhB (RhB) has the potential to cause toxic and persistent effects on the environment, thus requiring effective and simple treatment technologies. This study aims to examine the ability of CuO–clay composites to reduce RhB concentrations and analyze the kinetics of its degradation in a batch system with UV irradiation. Degradation tests were conducted on a 25 ppm RhB solution with variations in time of 60, 90, 120, 150, and 180 minutes. The RhB concentration was monitored using a UV–Vis spectrophotometer at λ_max 554 nm, while the concentration reduction data was analyzed using first-order and second-order kinetic models. The results showed that the CuO–clay composite was able to significantly reduce the RhB concentration within 180 minutes of contact time, with a final concentration of 0.0274 ppm. Kinetic analysis indicated that the RhB reduction process followed a pseudo-first-order model with a rate constant k(₁₎= 0.0378 min^(⁻¹⁾ and a coefficient of determination R(²⁾= 0.998. These findings confirm that CuO–clay composites have the potential to be developed as effective and economical functional materials for treating liquid waste containing RhB.