厌氧出水回流对柠檬酸废水处理的影响

将处理柠檬酸废水的内循环厌氧反应器的出水以不同比例回流至水解酸化池，研究了厌氧出水回流对水解酸化过程及厌氧处理过程的影响。实验结果表明：厌氧出水参与水解酸化能明显提高水解酸化池的出水pH及废水的预酸化度，厌氧出水添加比（V（厌氧出水）∶V（废水））为1∶4及以上时，可使水解酸化池的出水pH稳定在4.5以上，同时达到10.0%以上的预酸化度，且对NH₃-N的去除能力明显增强；随水解酸化时间的延长，水解酸化池的出水pH先减小后增大，而预酸化度则呈上升趋势；水解酸化3.0 h时，厌氧出水COD降至1 200 mg/L以下。厌氧出水参与水解酸化能增强厌氧反应器中微生物对挥发性脂肪酸的利用率，提高厌氧反应器出水的pH，降低出水COD及其波动幅度，增强厌氧系统的稳定性及自我修复能力。

Effect of Anaerobic Effluent Reflux on Treatment of Citric Acid Wastewater

The effluent from the internal circulation anaerobic reactor for treatment of citric acid wastewater was returned to the hydrolyzation-acidification pool with different reflux ratio. The effects of the anaerobic effluent reflux on the hydrolyzation-acidification process and anaerobic treatment process were studied. The experimental results show that：The pool effluent pH and pre-acidification degree can be greatly increased with the addition of the anaerobic effluent,and when the V(anaerobic effluent)∶V(wastewater) is 1∶4 and above,the pool effluent pH can be kept above 4.5 with above 10.0% of pre-acidification degree,and the removal of NH₃-N can be significantly increased；With the extension of hydrolyzation-acidification time,the pool effluent pH is decreased in the beginning and then increased,while the pre-acidification degree is increased；When the hydrolyzation-acidification time is 3.0 h,the anaerobic reactor effluent COD is decreased below 1 200 mg/L. The anaerobic effluent reflux can improve the utilization of volatile fatty acids by microorganism in the anaerobic reactor,increase the anaerobic reactor effluent pH,decrease the effluent COD and its fluctuation range,and enhance the stability and self-restoration capability of the anaerobic reactor.