Enhanced wastewater treatment performance by integrating coagulation and granular activated carbon with low-cost ceramic membrane bioreactor

This study investigates the integration of coagulation-flocculation (CF) and granular-activated carbon column (GACC) with a low-cost ceramic membrane bioreactor (LCMBR) to enhance wastewater treatment efficiency. Two integrated treatment processes, LCMBR-GACC and LCMBR-CF-GACC, were evaluated to determine their effectiveness in improving water quality for non-potable applications. In the LCMBR-GACC process, a GACC column was incorporated into the LCMBR system, while the LCMBR-CF-GACC process introduced an additional CF unit after the LCMBR. The LCMBR was operated in a 24-hour intermittent aeration mode (24 h on/24 h off) at a flux rate of 0.4 m/d and a hydraulic retention time (HRT) of 1.5 days. The study conducted CF using a 50 mg/L Fe³ ⁺ dose and operated the GACC column with an empty bed contact time (EBCT) of 30 minutes. Results demonstrated that LCMBR alone achieved 98 % removal of chemical oxygen demand (COD) and 88 % removal of ammonia (NH 3 -N). The GACC and CF-GACC integration significantly enhanced the removal of phosphate (PO 4 -P), COD, and NH 3 -N. The LCMBR-CF-GACC process exhibited superior performance, achieving final effluent concentrations of < 2 mg/L COD, < 0.2 mg/L PO 4 -P, < 0.05 mg/L NH 3 -N, < 3 mg/L NO 3 -N, and < 0.3 mg/L NO 2 -N, meet drinking water standards and make it suitable for non-potable domestic applications. The integrated LCMBR process offers an energy-efficient and cost-effective solution for advanced and sustainable wastewater treatment, particularly suitable for small communities through a decentralized approach.