直湖港陆域水产养殖区污染特征及输出通量研究

针对太湖主要入湖河流直湖港陆域水产养殖污染问题,于2010年4~11月对其水产养殖较为集中区域进行排污量和水质同步监测与分析,并对其污染特征及输出通量进行研究。结果表明:传统养殖模式下,主要污染物为总磷(TN)和CODMn,两者占总输出通量的88.1%;鳖塘、鱼塘与鱼苗塘TN含量随时间变化波动较大,蟹塘TN含量始终维持在较高水平,夏季TN含量明显增高,有机污染严重,各养殖塘变化趋势相似,其余指标常年处于平稳;鱼苗塘和鱼塘向水环境中TN的年排放量分别为135.9kg/hm2和97.5 kg/hm2,总磷、有机污染物及其他污染物均为各类养殖对象中最高;传统养殖模式下,养蟹死亡率较高,生产单位水产品所带来的污染较为严重;利用单位面积土地养殖鱼类和鱼苗的总污染物输出通量高,分别达377.85 kg/hm2和485.7 kg/hm2,是鳖塘的5~6倍,对环境压力较大;养殖塘投饵量与TN和亚硝态氮的输出通量相关性较大、为0.97和0.94,与高锰酸盐指数的相关性较低、为0.79。

Research on characteristics of traditional aquaculture pollution and transport fluxes of Zhihugang river in Taihu lake

In the light of pollution problems of Taihu Lake Harbor Land aquaculture,the paper monitored and analysed the water quality of its aquaculture focused regional between 4～11 in 2010,and studied its pollution characteristics and output fluxes.The results showed that,under the traditional cultivation pattern,the main pollutants were TN and CODMn,both the total output flux of 88.1%.In turtle pond,fish pond and fry pond,TN concentration changed with time.In crab pond,TN concentration had always been maintained at a high level,which increased significantly in the summer.Organic pollution was serious,there was a similar tendency in the breeding pond,the remaining indexes all the year round in a smooth.Emissions of TN from fry pond and fish ponds to water environment were 135.9 kg/hm2 and 97.5 kg/hm2.TP,CODMn,and other contaminants were all highest object in the farming pond.In the traditional cultivation pattern,there was a higher mortality rates raise crab,pollution of unit production of aquatic products were more serious,utilization per unit area of land farmed fish and fry’s total output of pollutants flux was high,were 377.85 kg/hm2 and 485.7 kg/hm2,was higher than turtle pond by 5～6 times,which made a greater pressure on the environment.Output flux of TN and NO3-with greater correlation of 0.97 and 0.94,and lower correlation with CODMn of 0.79.