Comparison coal fly ash-based adsorbent and advanced oxidation process for textile wastewater treatment

Abstract Textile wastewater often contains complex, carcinogenic dyes such as Direct Red-81, which pose serious environmental hazards due to their resistance to degradation. This study addresses the challenge of effectively removing such pollutants by comparing two treatment methods: adsorption using chemically activated coal fly ash (CFA) and advanced oxidation processes (AOPs) using the Fenton-like reaction with Mn 2 ⁺/H₂O₂. CFA was activated using KOH and H₂SO₄ solutions, and both methods were applied to treat textile wastewater containing Direct Red-81 dye. The results showed that the AOPs method with Mn 2 ⁺/H₂O₂ (0.5 g:200 mL) achieved superior removal efficiencies for the dye, biochemical oxygen demand (BOD), and chemical oxygen demand (COD), with removal rates reaching approximately 90%. Conversely, the adsorption process using CFA was more effective in removing total suspended solids (TSS), achieving over 90% removal. These findings suggest that while AOPs with Mn 2 ⁺/H₂O₂ are highly effective for degrading organic pollutants like dyes and reducing BOD and COD, CFA-based adsorption is more suitable for TSS removal. A combined treatment approach may therefore be recommended for comprehensive textile wastewater remediation.