江苏省太湖流域水功能区纳污能力及限制排污总量研究

水功能区纳污能力及限制排污总量研究是制定区域水污染控制规划的基础。依据《江苏省地表水(环境)功能区划》,结合江苏省太湖流域现状水质和污染概况,针对河网区和湖库区分别采用一维、二维非稳态模型,计算江苏省太湖流域水功能区纳污能力,在此基础上,引入最大污染物入河量,核定50%、75%和90%水文保证率下的最大污染物入河量分别为2015年、2020年和2030年限排总量。结果表明:(1)CODMn和氨氮纳污能力分别为284 803 t/a和22 448 t/a;(2)2015年CODMn和氨氮限排总量分别为221 867 t/a和20 520 t/a,2020年和2030年限排总量递减,均小于纳污能力;(3)CODMn和氨氮入河量削减率分别为21.8%和46.3%,与水质超标率相差均在25%以内,基本相符。江苏省太湖流域纳污能力、限排总量、污染物入河量削减率和水质超标率之间关系合理,计算结果合理。研究成果为太湖流域水环境控制规划提供决策依据。

Study on assimilative capacity and limitation of water pollutant gross of water function zones in Taihu Lake area of Jiangsu Province

Study on assimilative capacity and limitation of water pollutant gross of water function zones is the basis for making a regional water pollution control plan.According to water function zonation of Jiangsu,current water quality and pollution in Taihu Lake area of Jiangsu Province,the assimilative capacity was calculated by one-dimensional,two-dimensional non-steady-state model.Based on that,the maximum amount of pollutant into the river was introduced,and it under 50%,75%,90% hydrology guaranteed rates were defined as the limitation of water pollutant gross in 2015,2020,2030,respectively.Results indicate as follows,(1)the assimilative capacity of CODMn and NH3-N are 284 803 tons per year and 22 448 tons per year,respectively;(2) the limitation of water pollutant gross of CODMn and NH3-N are 221 867 tons and 20 520 tons in 2015,respectively,descending in 2020 and 2030,which are less than the assimilative capacities;(3) Reduction rates into the river of CODMn and NH3-N are 21.8% and 46.3%,which are consistent with the excess rates of water quality within 25% difference.The relationship between the assimilative capacity,the limitation of water pollutant gross,the pollutant reduction rates,the excess rates of water quality are reasonable,so the results are reasonable.The research results provide a basis for decisions making in Taihu Lake area water environmental control plan.