池塘工程化循环水养殖对水环境的季节变化影响

Effects of Water Environment of Seasonal Change in Pond Engineering Recirculating Aquaculture

池塘生态工程化循环水养殖模式以其具有"集中养殖、主体净水"的优势而成为当前池塘养殖的主推模式之一。该研究选择工程化养殖系统的水体为对象,通过对养殖水体不同季节进行监测、分析,探讨在该种养殖模式下水体环境的季节变化情况。结果表明:水体的DO、p H秋冬季较高(其变幅在5.5~7.8 mg/L、8.0~8.3)、春夏季较低(变幅在3.1~5.6 mg/L、7.6~7.9)的变化特点;夏季可溶性营养盐PO43--P、NO3--N、NH4+-N、NO2--N在集中养殖区处于较高含量,水体TN、TP含量较高,其均值分别为4.038 mg/L、0.178 mg/L,而在夏季处于全年最高值;较高的氮磷含量导致水体中有机质和藻类大量增加,夏季水体中COD、Chl-a含量分别为25.7 mg/L、52.6 mg/m3。养殖水体中较高的氮磷营养盐含量,不但水体藻华增殖严重,而且水体的水环境质量下降和养殖尾水达标排放的净化压力增大。建议后期养殖中控制外围水域中水产品养殖数量、提高水体自净能力和水环境质量。

The ecological engineering circulating aquaculture pond model has become one of the main models of pond aquaculture because of its advantages of"concentrated aquaculture and main water purification".The water body of the engineering aquaculture system was selected as the object in this study.Seasonal changes of the water environment under this aquaculture model were discussed with monitoring and analyzing the different seasons of aquaculture water body.The results showed that the DO and p H values of water bodies were higher in autumn and winter(with a variation of 5.5~7.8 mg/L and 8.0~8.3)and lower in spring and summer(with a variation of 3.1~5.6 mg/L and 7.6~7.9),respectively.In summer,soluble nutrients PO43--P、NO3--N、NH4+-N、NO2--N are at a high level in concentrated aquaculture areas.TN and TP contents in water are relatively high,with an average value of 4.038 mg/L and 0.178 mg/L,respectively.The higher nitrogen and phosphorus content led to a large increase of organic matter and algae in the water,and the COD and Chl-a contents in the water were25.7 mg/L and 52.6 mg/m3in summer,respectively.Higher nitrogen and phosphorus nutrient content in aquaculture water not only causes serious proliferation of algal blooms in water,but also reduces the water environment quality of water and the purification pressure of the discharge of aquaculture tail water to meet the environmental standards.It is suggested to control the aquaculture quantity of aquatic products in peripheral waters and improve the self-purification capacity and water environment quality.