常熟农村不同水体氮磷污染状况

Nitrogen and Phosphorus Pollution in Various Waterbodies in Rural Area of Changshu

于2007年11月至2008年10月,对常熟市辛庄镇不同水体氮磷污染状况进行定点观测,初步探讨了河道和鱼塘水体氮磷浓度的变化特征及其污染来源。结果表明:辛庄镇河道水样无机氮、总氮、正磷酸盐和总磷的平均质量浓度分别为2.07、2.31、0.30和0.53 mg.L-1,表明辛庄镇河水氮磷污染已十分严重。河道和鱼塘水体氮形态都以无机氮为主,分别占总氮的89.6%、72.7%;磷形态以可溶态为主,分别占总磷的73.6%、71.1%。河水硝态氮、铵态氮、总氮、无机氮、正磷酸盐、可溶性磷和总磷平均质量浓度分别比鱼塘水高0.30、0.17、0.11、0.47、0.12、0.15和0.12 mg.L-1。河道和鱼塘水体硝态氮、无机氮和总氮浓度随时间的变化趋势较一致,正磷酸盐、可溶性磷和总磷浓度随时间的变化趋势则显著不同。河水氮磷污染源主要来自生活污水及养猪场废水,鱼塘水体的氮磷污染则与饵料和肥料的投入有很大关系,大气氮沉降也是导致水体氮浓度升高的重要原因。

From November of 2007 to October of 2008, stationary observation was performed of nitrogen （N） and phosphorus （P） pollution of rivers and fish ponds in Xinzhuang Town, Changshu,to explore variation of N and P concentrations in the waterbndies and sources of the pollutants. Results show that in the river water,the mean concentration of inorganic N, total N, soluble P and total P was 2.07,2.31,0. 30 and O. 53 mg . L^-1 , respectively, indicating that the river was severely polluted. In the rivers and fish ponds,inorganic N dominated the pollutant N accounting for 89. 6% and 72. 7% ,respectivelh and soluble phnsphorus did the pollutant P, accounting for 73.6% and 71.1% , respectively. Generally, the mean couaentrations of nitrate N,inorganic N and total N in the rivers and fish ponds showed a similar variation trend,while the mean concentrations of phosphate,soluble P and total P differed in variation between the rivers and fish ponds. Nitrogen and phosphorus pollution in the rivers came mainly from domestic sewage and pig farms waste water, while nitrogen and phosphorus pollution in the fish ponds from application of baits and fertilizers, and atmospheric nitrogen deposition was also an important contributor to nitrogen pollution of the waterbodies.