Characteristics Of Rainwater Pollution And Environmental Risk Control In Shanghai Chemical Industry Park

With the rapid process of urbanization,rainwater runoff pollution has gradually become an important source of water pollution load.The potential high pollution risk of rainwater in chemical areas is beginning to cause concern,but both the monitoring of initial rainwater and the study of actual discharge in the chemical areas need to be perfected.Based on the related project of Shanghai Chemical Industry Park,this paper systematically studies the characteristics of rainwater pollution in chemical area from the initial rainwater to the end of the rainwater discharge,and provides a scientific reference for the prevention and control of the environmental risks of rainwater pollution in the chemical area.Based on the legal standards of rainwater management and pollution control policies of chemical areas at home and abroad,the paper uses questionnaires and other methods to investigate the current situation of rainwater management and risk control of 50 enterprises in Shanghai Chemical Industry Park,and conducts research and evaluation from the three aspects of rainwater management standards,rainwater pollution treatment and pollution risk control in the park.The pollution characteristics are studied from two aspects:the initial rainwater and end discharge of rainwater,which are the key links of the rainwater pollution management and control found in the investigation.Through the monitoring and mathematical statistics of different functional areas,this paper analyzes the variation rules and pollution characteristics of multiple water quality indicators,and discusses the differences in the degree of pollution in different functional areas of the initial rainwater in the park.The high-frequency data of more than 30,000 online monitoring in rain drains were analyzed,the emission and pollution characteristics of pH and TOC were studied,and the pollution characteristics of different rainwater discharge flow segments were discussed.Aiming at the status of management and risk prevention of the park and the characteristics of rainwater pollution,the main problems and countermeasures for the control of rainwater pollution in Shanghai Chemical Industry Park are proposed.The main findings and results of this paper are as follows:（1）At present,the legal standards that can be based on and implemented in rainwater management and pollution prevention in domestic chemical industrial parks are promulgated by different departments or from different industry backgrounds,and there may be problems such as interpretation of standards and other issues.In the Shanghai Chemical Industry Park,it is mainly reflected in the difference of the determination and collection volume of initial rainwater,besides the implementation standards of rain discharge are different.The initial rainwater treatment mode is that each enterprise collects it separately and sends it to the centralized sewage treatment plant.The level of rainwater risk prevention and maintenance of rain drainage system between enterprises varies greatly.The initial rainwater pollution control and the monitoring discharge of rain drains are important links for rainwater pollution risk control.（2）There is a certain pollution risk in the initial rainwater in Shanghai Chemical Park,the concentration of pollutants is the trend of first growth and then decrease,most pollutant concentrations in rainfall 15min to 20min is still growing,so most enterprises take only control of the initial rainfall 15min rain water there is a certain risk.The degree of exceeding the standard is different,and the pollution degree varies in different functional regions.The probability of exceeding the standard of CODcr,SS,NH₃-N and TOC is relatively high.The risk of pollution in tank area,critical waste storage area and part of the production workshop is relatively high.（3）Analysis of high-frequency data from online monitoring of rainwater discharge outlets in the Shanghai Chemical Industry Park shows that the risk of pH pollution varies seasonally,and the risk of pollution in summer and autumn is relatively large.The annual distribution characteristics of TOC are related to the actual situation of each enterprise,the average concentration difference of TOC is small among different enterprises,and the decisive factor affecting the difference of TOC pollution load level is the rain drain flow of enterprises.Through the study of water quality characteristics in different flow segments,it is found that the risk of pH and TOC exceeding the standard will increase when the flow is small,and the risk of TOC exceeding the standard will be increased when the flow is very large.（4）In order to solve the main problems existing in the prevention and control of rainwater management and pollution risk in Shanghai Chemical Industry Park,the following suggestions are put forward from the perspective of the whole process:reduce pollution from the source,standardize the collection and control of initial rainwater,including the collection volume and determination of initial rainwater,etc.;improve the supervision and management of the process,including the selection of scientific rainwater switching methods,ensuring the maintenance of rain drainage system;complete the rainwater monitoring system to strengthen end control,including the installation of online monitoring devices and the improvement of indicators.