The treatment of dye-contaminated wastewater, particularly from reactive dyes, remains a major environmental challenge

due to their high solubility and chemical stability in aquatic systems. This study evaluates the performance of microwave-

assisted advanced oxidation processes (MW-AOPs) for the degradation of selected reactive dyes, namely Remazole

Black-GR (RBGR), Sunfix Red S3B (S3B), Sunzol Blue RS (SBRS) and Sunazol Turquoise Blue G (DTB), under optimized

operational conditions. Experiments were conducted at pH 3.0 ± 0.2, aeration rate of 1.5 L/min, microwave power

of 275 W, treatment time of 60 min and initial dye concentrations of 100 mg/L. Preliminary coagulation–flocculation

tests achieved only 20.18–24.83% removal of RBGR, S3B and SBRS, confirming the limited efficiency of conventional

treatment processes. In contrast, MW-AOPs achieved substantial pollutant reductions, with COD removal efficiencies of

66.85% for SBRS, 58.28% for DTB, 53.47% for S3B and 57.73% for RBGR. Although BOD₅ removal was less pronounced,

the post-treatment BOD₅/COD ratio increased significantly, indicating enhanced biodegradability, particularly for

S3B. Kinetic analysis showed that dye degradation followed a second-order model, with the best fit observed for SBRS.

Principal component analysis (PCA) further revealed strong correlations between COD and BOD₅ removal and distinct

degradation behaviors among the dyes. Notably, complete color removal of RBGR was achieved within 20 min. The findings

highlight MW-AOPs as a promising standalone technology for the effective degradation of reactive dyes, offering

high efficiency and operational simplicity compared with conventional methods.