Optimization of isopropyl alcohol degradation by microwave-induced catalytic oxidation process

Isopropyl alcohol (IPA) is a common waste solvent from the semiconductor and optoelectronic manufacturing industries. The current study assesses the feasibility of microwave-induced catalytic oxidation process for synthetic IPA wastewater. The effect of three independent variables, including oxidant (hydrogen peroxide), initial IPA concentration, and dosage of catalyst (granular activated carbon, GAC) on the IPA removal efficiency, were investigated and optimized by response surface methodology based on central composite design. The estimated optimal working conditions were as follows: [H2O2] <0.132 M, GAC dosage = 108–123 g/L, and initial [IPA] = 0.038–0.10 M. The findings indicated that the dosage of GAC and the initial IPA concentration strongly affected the overall IPA removal. The values of R2 = 0.9948 and adjusted R2 = 0.9901 demonstrated that the response variability could be explained by the model expressing a satisfactory quadratic fit. Finally, the H2O2/GAC/MW process showed a faster and higher IPA removal rate than other processes tested.