Application of a combined process of moving-bed biofilm reactor (MBBR) and chemical coagulation for dyeing wastewater treatment

A combined process consisted of a Moving-Bed Biofilm Reactor (MBBR) and chemical coagulation was investigated for textile wastewater treatment. The pilot scale MBBR system is composed of three MBBRs (anaerobic, aerobic-1 and aerobic-2 in series), each reactor was filled with 20% (v/v) of polyurethane-activated carbon (PU-AC) carrier for biological treatment followed by chemical coagulation with FeCl₂.In the MBBR process, 85% of COD and 70% of color (influent COD=807.5 mg/L and color=3,400 PtCo unit) were removed using relatively low MLSS concentration and short hydraulic retention time (HRT=44 hr). The biologically treated dyeing wastewater was subjected to chemical coagulation. After coagulation with FeCl₂, 95% of COD and 97% of color were removed overall. The combined process of MBBR and chemical coagulation has promising potential for dyeing wastewater treatment.