生物—电氧化法去除海水养殖循环水污染物

为提高海水养殖循环水处理效率,降低处理成本,本研究采用曝气生物滤器与电化学阳极氧化组合工艺,考察了不同阳极电势、进水氨氮和亚硝酸盐浓度下系统对氨氮及亚硝酸盐等污染物的去除效果,研究了微生物与工作电极之间的相互作用,并分析了电化学反应能耗。在水力停留时间为45 min、1.4 V阳极电压、进水氨氮和亚硝酸盐浓度分别为4.5和1.3 mg/L条件下,生物—电氧化法对氨氮去除率达88.8%,高出对照组7.6%,出水氨氮和亚硝酸盐浓度分别为0.5和0.9 mg/L,COD去除率为88.2%,高出对照组19.4%,平均能耗0.040 kWh/m~3,电极表面微生物生长对阳极电氧化过程有促进作用,微生物功能预测显示实验组硝化功能占比为0.03%,对照组为0.07%。研究表明,生物—电氧化法对海水养殖循环水的污染物有良好的去除效果,具有一定的发展应用潜力。

Pollutants removal by biological-electrooxidation in marine aquaculture recirculating water

In order to improve the efficiency and reduce the cost of marine aquaculture circulating water treatment, the combined process of biological aerated filter and electrochemical oxidation was developed in this study. The removal efficiencies of ammonia and nitrite at different anode potentials, influent ammonia and nitrite concentration were investigated. The interaction between microorganisms and the anode was studied and the energy consumption of electrochemical reaction was analyzed. When the hydraulic detention time is 45 min, at the anode potential of 1.4V, and the ammonia and nitrite concentration is respectively 4.5 and 1.3 mgN·L-1, the removal rate of ammonia by biological-electrooxidation system reached 88.8%, which was 7.6% higher than that of the control group. The concentration of ammonia and nitrite in effluent is respectively 0.5 and 0.9 mgN·L-1, the removal rate of COD is 88.2%, which was 19.4% higher than the control group. The average energy consumption of electrochemical reaction is 0.040 kWh·m-3. Microbial growth on electrode surface can promote the anodic oxidation process. The results of microbial function prediction show that the proportion of nitrification function is 0.03% in the experimental group and 0.07% in the control group. In conclusion, the biological-electrooxidation method shows good performance of treating pollutants in the marine aquaculture circulating water and great potential for developing high efficient marine aquaculture recirculating water treatment.