Study on Treatment Efficiency of Pharmaceutical Wastewater by Combined Iron-Carbon Micro-Electrolysis-Biological Process

A combined process of aeration iron-carbon microelectrolysis(AICM)-hydrolysis acidification-anaerobic-aerobic was studied to treat pharmaceutical wastewater characterized by high nitrogen and refractory organic concentration. Results showed that when the AICM filter was controlled at the conditions of pH 3, iron-carbon ratio 1, gas-water ratio 10 and HRT 2h, the HRT of two-stage hydrolysis acidification, anaerobic and aerobic units were controlled at 2d, 2d, 2d and Id respectively, the biodegradability of wastewater could be greatly improved after treated by AICM filter and hydrolysis acidification units, the ratio of BOD₅/COD could be increased from 0.11 to 0.53. The removal rate of effluent COD, NO₃^--N and chroma from combined process achieved up to 99.18%, 99.13% and 98.41%, respectively, which could meet the discharge standard of water pollutants for pharmaceutical industry chemical synthesis products category (GB21904-2008).