基于“三池两坝”组合流程的池塘养殖尾水净化效能

Purification Efficiency of Pond Aquaculture Tail Water Based on the Combined“Three Ponds and Two Dams”Process

为探究"三池两坝"多级组合净化工艺中不同净化面积占比对标准化池塘养殖尾水净化效果的影响,以苏州市吴中区5个标准化池塘养殖区的水源水、养殖水以及净化水为监测对象,在养殖中、后期通过连续6个月的跟踪监测,分析了水质指标的变化及尾水净化后主要污染物的去除率。结果表明,尾水净化面积占比分别为11.4%和34.3%的两个"河蟹+青虾"低密度养殖区的净化效果良好,尾水净化后达到《太湖流域池塘养殖水排放要求》(DB32/T 1705—2018)的一级保护区排放标准,且净化效果与净化面积占比呈正相关。净化面积占比在11.7%~15.9%的"南美白对虾+罗氏沼虾"养殖区,去除率从高到低依次为NH_(4)^(+)-N>TN>TP,COD_(Mn)和TSS的去除率较低,净化后养殖尾水均能达到上述排放要求的二级保护区排放标准。

To explore the influence of different percentages of purification area in the "three ponds and two dams"process on the purification of tail water from pond aquaculture, water samples were collected from outside river( inlet water), culture ponds, and ecological ponds in the five standardized pond aquaculture sites in Wuzhong district of Suzhou city for a period of 6 months in the middle-to-late farming stages. Water quality changes were determined and the removal rates for major pollutants after tail water purification were analyzed. The results showed that in the two Eriocheir sinensis and Macrobrachium nipponense polyculture sites with low stocking density, where the area for tail water purification accounted for 11.4% and 34.3%, respectively, high purification efficiency was observed. The tail water after purification process met the discharge requirements of pond aquaculture water for first-grade preservation zone in Taihu lake basin. And the purification effect was positively correlated with the purification area percentages. In three Litopenaeus vannamei and Macrobrachium rosenbergii polyculture sites with purification area percentages ranging from 11.7% to 15.9%, the descending order of removal rates for major pollutants was as follows: NH_(4)^(+)-N>TN>TP, but the low removal rates for COD_(Mn)and TSS were observed. The tail water after purification could meet the above-mentioned requirements for second-grade protection zone.