嘉兴海域主要污染物环境容量及总量控制研究

Research on the environmental capacity and total control of main pollutants in the Jiaxing waters

嘉兴海域近年来海洋生态环境质量明显退化,实施污染物总量控制作为保证海域环境质量的根本措施之一,有助于嘉兴海域污染物的减排与治理工作,保障嘉兴海域可持续发展能力。基于嘉兴临近海域水动力-水质模型与现场监测结果,依据浙江省近岸海域环境功能区划的水质要求,采用响应系数法与线性规划方法,计算了该海域重要排放口的化学需氧量COD、无机氮与磷酸盐环境容量,并针对削减扩容影响的总量控制措施进行计算与评估。结果表明,研究海域COD总环境容量为2.97×10^(5)t/a,仍有较大富余,而无机氮与活性磷酸盐含量均超四类海水水质标准,超过海域无机氮与磷酸盐环境容量。对现有规划进行合理的量化数值模拟,削减措施尽管减少了一部分扩容引起的COD、无机氮与磷酸盐含量的增加,使其保持平稳,但仍需继续优化污水处理能力,减少氮磷营养盐的排放。研究结果可为沿海城市陆源污染物总量控制研究提供科学依据。

In recent years,the marine ecological environment quality in the Jiaxing waters has significantly deteriorated.Implementing total pollutant control measures as one of the fundamental measures to ensure the quality of the marine environment is conducive to reducing emissions and controlling pollutants in the Jiaxing waters,thereby safeguarding the sustainable development capacity of the area.Based on the hydrodynamic-water quality model of the adjacent waters of Jiaxing and field monitoring results,and in accordance with the water quality requirements of the environmental functional zoning of coastal waters in Zhejiang Province,the response coefficient method and linear programming method were adopted to calculate the environmental capacity of chemical oxygen demand(COD),inorganic nitrogen,and phosphate for the important discharge outlets in the area.Calculations and evaluations were carried out for the total control measures affecting reduction and expansion.The results indicate that the total environmental capacity of COD in the research area is 2.97×10^(5) tons/year,with a considerable surplus.However,the content of inorganic nitrogen and phosphate exceeds the fourth-class seawater quality standards,surpassing the environmental capacity of inorganic nitrogen and phosphate in the area.Rational quantified numerical simulations of existing plans show that although reduction measures have stabilized the increase in COD,inorganic nitrogen,and phosphate caused by expansion to some extent,it is still necessary to continue optimizing sewage treatment capacity and reducing the discharge of nitrogen and phosphorus nutrients.The research results can provide a scientific basis for the study of total pollutant control in coastal cities.