集中连片池塘的尾水处理系统中氮磷的时空变化规律

Spatial and temporal variation of nitrogen and phosphorus in wastewater treatment system of centralized continuous aquaculture ponds

为探明集中连片池塘排放尾水中氮磷经尾水处理系统各净化功能区的削减状况,分析尾水处理系统氮磷的削减机制,比较论证养殖尾水在各净化功能区的季节、月份变化规律,建立了一个具有养殖尾水处理系统的集中连片池塘养殖小区,对总氮(TN)和总磷(TP)在养殖试验周期内开展持续的时空监测。结果显示:生态沟渠和湿地+净化池塘组合构成的养殖尾水处理系统,6~10月间,对养殖尾水TN显著削减43.02%,TP显著削减30.39%。养殖小区排放水TN(1.318±0.408 mg/L)、TP(0.325±0.160 mg/L)符合SC/T 9101—2007《淡水池塘养殖水排放要求》一级排放标准。夏秋季与沿程交互作用对TN有显著影响(P<0.05),夏秋季与沿程对TP不存在交互效应,夏秋季对TP的主效应差异不显著(P>0.05)。研究表明:湿地+净化池塘组合对TN的净化效果优于生态沟渠,生态沟渠是TP的主要净化功能单元,养殖尾水处理系统秋季对TN的削减优于夏季。

In order to investigate the reduction status of nitrogen and phosphorus through each purification function zone,analyze the cutting mechanism of nitrogen and phosphorus in aquaculture wastewater treatment system,and compare and demonstrate the seasonal and monthly variations of aquaculture wastewater in each functional area of the system,an aquafarm composed of aquaculture pond,ecological ditch,wetland and purification pond was constructed.Continuous spatiotemporal monitoring of total nitrogen(TN)and total phosphorus(TP)was carried out during the aquaculture test period.Results showed that the aquaculture wastewater treatment system composed of ecological ditch,wetland and purification pond significantly reduced TN by 43.02%and TP by 30.39%from June to October.TN(1.318±0.408 mg/L)and TP(0.325±0.160 mg/L)fully met the first-level discharge standard of fresh water pond aquaculture discharge requirements(SC/T 9101-2007).The spatiotemporal interaction between summer and autumn had a significant effect on TN(P<0.05).There was no interaction effect on TP between summer and autumn and space-time along the route.The main effect of summer and autumn on TP was not statistically significant(P>0.05).The research demonstrated that ecological ditch was the main purification unit in terms of TP.The purification effect of wetland+purification pond combination on TN was better than that of ecological ditch.The TN reduction effect in autumn was better than that in summer in the aquaculture wastewater treatment system.