Pilot-Scale Study of an Integrated Membrane-Aerated Biofilm Reactor System on Urban River Remediation

Coupled with the hydrolysis-acidification (HA) process, the two-stage continuous flow membrane-aerated biofilm reactor (MABR) system was designed for urban river treatment, and parameter optimization was investigated in accordance with the average effluent concentrations of chemical oxygen demand (COD), ammonia nitrogen (NH4-N), total nitrogen (TN), and suspended solids (SS). The optimal process parameters included temperature, 19 degrees C; pH, 8.0; the reflux ratio, 200%; and hydraulic retention time (HRT), 15 h, based on which the operational feasibility of the integrated system was further evaluated during the 40 days pilot -study for the urban river treatment. Results indicated that the integrated system exhibited highly effective performance for the urban river remediation with similar to 87% COD removed and >95% NH4+-N removed. Nitrification and denitrification were simultaneously achieved inside the system. The TN removal process was enhanced by the reflux system with the effluent TN concentration remaining at similar to 1.8 mg/L. The systematic applicability for the water quality improvement of the urban river was effectually confirmed on the pilot-scale study, which was conducive to the technical engineering application.