Experiment On Removal Of 2, 4, 6-Trichlorophenol In Micro-polluted Surface Water By MBR Process

2,4,6-trichlorophenol (TCP), which exists universally among surface water, belongs to synthetic organic chemicals. In spite of low concentration, TCP has enormous potential hazard to health of human being. A lab-scale MBR was performed to investigate the removal of trace TCP from micro-polluted surface water, in order to satisfy the upgrading criteria of drinking water.Continuous lab-scale test showed that both the aesthetic quality and NH3-N of treated water from MBR could comply the requirement of the Water Quality Standard for Urban Water Supply (CJ/T206-2005) issued by the Ministry of Construction. MBR technology could also remove significantly the organic matters from micro-polluted raw water.The results of continuous measurement over 100 days proved that acclimated microorganisms had excellent capacity in removal of TCP. The average removal rate of TCP by MBR could achieve 98.18% during steady operation. When the TCP concentration in the raw water fluctuated dramatically and the average concentration was 172.6μg/L, the average TCP concentration in the treated water was below 3μg/L. All of TCP concentration measured under steady operation stage met the drinking water quality requirements.Batch tests showed that biological degradation played a major role in TCP removal by MBR. Based on the experimental data, it was found that biodegradation of TCP follows zero-order kinetics with a rate constant of 1.65μg/(L·min). Besides, the maximum specific substrate utilization rate qmax and the affinity constant Ks were experimentally determined using a steady fed-batch reactor process (FBR). From the FBR result, qmax and Ks values were 0.059 d-1 and 0.236 mg/L respectively.In conclusion, the removal of TCP from micro-polluted lake water by MBR was highly effective, with the mechanisms of secondary substrate utilization and NOM inducing effect. It was found that when MBR was used to treat micro-polluted water, microorganisms with high affinity for substrate could be cultivated in MBR, which was favorable for the biodegradation of trace TCP.