光合细菌与水生植物联合作用对暗纹东方鲀养殖尾水的净化效果

Purification efficiency of Takifugu obscurus aquaculture tail water by combination of photosynthetic bacteria and aquatic plants

为达到高效净化淡水养殖尾水,利用实验室水质测定方法,研究了光合细菌(Photosynthetic bacteria)分别与凤眼莲(Eichhornia crassipes)、蕹菜(Ipomoea aquatica)、狐尾藻(Myriophyllum verticillatum)3种不同生活类型的水生植物联合作用对暗纹东方鲀(Takifugu obscurus)养殖尾水的净化效能,分析了水质指标(TAN、NO2--N、NO3--N、TSS、COD、TN和TP)的变化及其去除率。结果表明:3种水生植物中蕹菜生长最快,其次为凤眼莲,狐尾藻生长最慢。光合细菌+水生植物联合作用对淡水养殖尾水的净化效果显著,栽种水生植物的组合(PA1、PA2、PA3)对尾水中(P)和对照组(P<0.05),对TAN、COD的去除率不显著(P>0.05),但均大于对照组;其中栽种蕹菜的组合(PA2)去除效果最佳,NO2--N、TN、TP和COD值均在6 d内迅速降低,TAN浓度于9 d内降至最低,NO2--N和TSS于15 d时降至最低,并均趋于稳定;最终TAN、NO2--N、NO3--N和TSS的去除率达到了94.34%、99.7%、99.11%、97.23%,TN、TP和COD的去除率达到了87.74%、86.26%和34.07%。各项指标除TSS外均达到了我国农业农村部要求的《淡水养殖尾水排放要求》(SC/T 9101-2018)一级排放标准。根据以上结果,选出的最佳净化组合为光合细菌和蕹菜组合。此结果可为淡水养殖尾水处理系统的设计和构建提供参考。

In order to achieve the high efficient purification of freshwater aquaculture tail water,the purification efficiency of Takifugu obscurus aquaculture tail water by photosynthetic bacteria combined with one of three different life forms of aquatic plants Eichhornia crassipes,Ipomoea aquatica and Myriophyllum verticillatum was studied through laboratory water quality determination methods,the changes and removal effects of various parameters of water quality(TAN,NO2--N,NO3--N,TSS,COD,TN and TP)were analyzed.The results showed that Ipomoea aquatica grew fastest of three aquatic plants,Eichhornia crassipes followed,and Myriophyllum verticillatum grew slowest.The combined systems of photosynthetic bacteria and aquatic plants had a significant purification effect on the freshwater aquaculture tail water,the removal effects of NO2--N,NO3--N,TSS,TN and TP in tail water by the combined systems with aquatic plants(PA1,PA2,PA3)were better than those of photosynthetic bacteria group(P)and control group(P<0.05),but the removal effects of TAN and COD were not significant(P>0.05),but they were higher than those of control group.Among them,the removal effect of the combined system with Ipomoea aquatica(PA2)was the best,and the concentrations of NO2--N,TN,TP and COD decreased rapidly within 6 days,the concentration of TAN decreased to the lowest value within 9 days,and gradually approached to the stable values.The final removal rates of TAN,NO2--N,NO3--N and TSS reached 94.34%,99.7%,99.11%and 97.23%,respectively,and the removal rates of TN,TP and COD reached 87.74%,86.26%and 34.07%,respectively.All the indicators,except for TSS,could meet the first-level discharge standards in the Discharge Requirements for Tail Water of Freshwater Aquaculture(SC/T9101-2018)required by the Ministry of Agriculture and Rural Areas of China.Therefore,the best combination was photosynthetic bacteria and Ipomoea aquatica.The research results can provide a reference for the design and construction of freshwater aquaculture tail water treatment system.