深圳农业面源污染与近岸水体富营养化关系研究 III.水产养殖排污分析

Relationship between agricultural NPS and eutrophication in coastal water of Shenzhen III.The analysis of the discharging pollutants from aquaculture

对1991年至2000年间深圳内陆和近岸水产养殖业的排污量进行估算,分析其演变趋势,并对同时期深圳市的点源污染和农业面源污染进行了比较,结果表明:(1)深圳市水产养殖业排污也是深圳近海水体富营养化主要成因之一,自1994年之后其对近海水体污染有加重趋势;(2)在农业面源中,畜禽养殖业排污量最大,其次是水产养殖,再次是农田化肥流失排污;(3)在点源污染中,城市生活污水已成为主要污染源,工业废水排污在点源污染中的比重有较大程度的降低;4)点源污染与面源污染相比,在排放COD量的比例上,前者是后者的两倍多,在排放TN量所占比例上,二者相近,在排放TP所占比例上,前者小于后者。

The amount of pollutants from aquaculture was estimated in Shenzhen during 1991 - 2000, and the evolutionary tendency was analysed . The point source pollution and Non-point source pollution of the same period were compared finally. The conclusions were as follows： firstly, the pollutants from the aquaculture in Shenzhen were the main reasons for the eutrophication in the coastal water, and caused more serious pollution after 1994; secondly, in agriculture NPS, livestock and poultry breeding discharged the largest amount of the pollutants, aquaculture second and the loss of chemical fertilizer third; Thirdly, in the point pollution source, domestic sewage became a main pollution source, and the percentage of the pollutants from the industrial wastewater have a obvious decrease; fourthly, the comparisons between the point pollution source and the agricultural NPS showed that the former is twice to the latter in the percentage of discharging amount of COD, and close to the latter in that of TN and smaller than the latter in that of TP.