Integrated approach to textile wastewater treatment: Investigating electrocoagulation, MBBR, and adsorption synergy

The textile industry generates wastewater that high in colour, chemical oxygen demand (COD), and total suspended solids (TSS), and which is difficult to process using conventional biological or chemical techniques. This study presents the performance of a pilot-scale integrated treatment system combining electrocoagulation with clarifier air flotation (EC-CAF), a moving bed biofilm reactor (MBBR), and activated carbon adsorption for the advanced treatment of textile wastewater. Real effluent (50 m³/day) was treated under optimised operating conditions. The EC-CAF unit, operating at a current density of 628.90 ± 88.28 A/m², achieved removal efficiencies of 68.1 % for COD, 97.3 % for TSS, and 98.0 % for colour. The MBBR, designed with a media surface area of 500 m²/m³ and loaded at 1.07 ± 0.72 g COD/m³·day, achieved additional COD removal of 56 ± 19.5 %. The final adsorption stage using granular activated carbon (iodine number 1000 mg/g) removed 46.2 ± 23.3 % COD, 59.2 ± 25.9 % TSS, and 65.1 ± 20.2 % colour. Overall, the integrated system reached 93.74 % COD, 99.57 % TSS, and 99.62 % colour removal. The energy consumption was 5.18 kWh/m³, while the treatment cost was USD 0.435/m³, substantially lower than that for conventional chemical coagulation–adsorption systems, which cost USD 13.21/m³. Challenges such as electrode passivation and fluctuating influent loads were managed through operational controls and buffer tanks. The study provides evidence of a cost-effective, scalable, and energy-efficient approach for reusing textile wastewater, offering scope for improvement through the integration of renewable energy and more widespread industrial uses.