| 摘要: |
| 【目的】探究池塘养殖尾水处理系统整体及各级沿程在不同水力负荷条件下，总氮（TN）、总磷（TP）的变化规律，探明系统对TN、TP净化效果的最佳运行水力负荷。【方法】对5 hm2养殖池塘配套的约0.5 hm2养殖尾水处理系统,采用低（0.012 m/d）、中（0.023 m/d）、高（0.035 m/d） 3种水力负荷运行，在系统各级沿程(表面流湿地(SFW)、一级净化池塘(PP1)和二级净化池塘(PP2))采集水样，检测TN、TP质量浓度，运用双因素重复测量方差分析法，分析各水力负荷条件下各级沿程TN、TP质量浓度的差异变化，以及养殖尾水处理系统整体和各级净化功能区对TN、TP的净化处理效果，通过PP2、TN、TP去除率与水力负荷的拟合函数关系计算最佳运行水力负荷。【结果】养殖尾水处理系统中TN、TP质量浓度在各级沿程、不同水力负荷间存在极显著差异（P<0.01），且沿程与水力负荷存在交互作用（P<0.05）。随水力负荷的增加，系统整体对TN和TP去除率均呈线性下降（TN去除率由低水力负荷时的57%下降为高水力负荷时的23%，TP去除率由低水力负荷时的70%下降为高水力负荷时的46%）。随水力负荷的增加，PP2在系统各净化功能区中对养殖尾水TN净化效果的贡献度由低水力负荷时的22%逐渐增大至高水力负荷时的93%。PP2可优化获得最佳水力负荷约0.075 m/d，对应TN、TP最佳去除率均为28%。【结论】多净化功能区组合的养殖尾水处理系统宜建立基于优化水力参数的运行策略，就试验养殖尾水处理系统整体而言，若发挥各净化功能区最佳净化性能，宜采用中水力负荷（0.023 m/d）运行；若以污染物去除总量最优化为目的，需根据养殖池塘排放尾水的水质状况建立运行策略。 |
| 关键词: 水产养殖 养殖尾水处理 水力负荷 净化效果 |
| DOI： |
| 分类号: |
| 基金项目:上海市科技兴农重点攻关项目(2019-02-08-00-07-F01130)；上海长江口主要水生动物人工繁育工程技术研究中心项目(13DZ2251800)；上海市农业领军人才项目(沪委农办2018-60号) |
|
| Effect of different hydraulic load rates on purification effect of aquaculture wastewater treatment system |
|
XU Jiabo,SHI Yonghai,LIU Yongshi,et al
|
| Abstract: |
| 【Objective】This study explored the changes of total nitrogen (TN) and total phosphorus (TP) in whole aquaculture wastewater treatment system under different hydraulic load conditions and ascertained suitable operating hydraulic load for optimal TN and TP purification effect.【Method】The aquaculture wastewater treatment system (about 0.5 hm2) of aquaculture ponds (5 hm2) was operated at three hydraulic load rates （surface flow wetland (SFW)，primary purification pond (PP1) and secondary purification pond (PP2)）of low (0.012 m/d),medium (0.023 m/d) and high (0.035 m/d).Water samples were collected along each stage to determine the concentrations of TN and TP.The two-factor repeated measurement variance analysis method was used to analyze the variations in TN and TP.The TN and TP purification effects of the aquaculture wastewater treatment system and various functional areas were then analyzed.The fitting functions between TN and TP removal rates and hydraulic load rate were used to calculate the optimal operating hydraulic load rate.【Result】The concentrations of TN and TP in the aquaculture wastewater treatment system had extremely significant differences among different hydraulic load rates (P<0.01) and along the system path (P<0.01),and there was interactions among different hydraulic load rates and different paths (P<0.05).With the increase of hydraulic load rate,the overall removal rates of TN and TP decreased linearly.TN removal rate decreased from 57% at low hydraulic load rate to 23% at high hydraulic load rate and TP removal rate decreased from 70% to 46%.With the increase of hydraulic load rate,the contribution of secondary purification pond PP2 to TN purification of the aquaculture wastewater in each purification function area increased gradually from 22% at low hydraulic load rate to 93% at high hydraulic load rate.The optimal hydraulic load rate obtained for the secondary purification pond PP2 was about 0.075 m/d with optimal same TN and TP removal rates of 28%.【Conclusion】The operation strategy of hydraulic parameters should be established for the aquaculture wastewater treatment system with the combination of multiple purification functional areas.In terms of the aquaculture wastewater treatment system in this study,it was advisable to operate under a medium hydraulic load rate of 0.023 m/d to obtain optimal purification performance.If aiming to optimize total removal amount of pollutants,the operation strategy should be established according to the water quality of the wastewater discharged from aquaculture ponds. |
| Key words: aquaculture aquaculture wastewater treatment hydraulic load purification effect |
