Abstract:

Currently, industrial enterprises primarily utilize two initial rainwater collection methods based on time (first 15 ~ 30 min) and depth (first 20 ~ 30 mm) according to the relevant specifications and standards. However, online monitoring and control of rainwater discharge water quality in chemical industrial parks is relatively weak and there is limited research on the pollution control effects of different initial rainwater collection methods. This study utilized monitoring data from rainwater outlets in a Shanghai chemical industrial park to investigate the pollution risks associated with different initial rainwater collection methods and align them with the requirements for pollution emission load control and water quality compliance. The cumulative distribution curve of the runoff pollution load was used to examine the response of key water quality indicators to rainfall. This study discusses variations in different initial rainwater collection and management methods in chemical industrial parks from the perspective of pollution reduction. Chemical companies generally adopt time-based initial rainwater collection for operational convenience during continuous heavy rainfall, with its rainwater pollution control effect being relatively limited. Therefore, it is recommended that chemical industrial parks adopt depth-based collection methods tailored to rainfall characteristics to effectively reduce rainwater pollution loads and mitigate pollution risks.

Key words: initial rainwater, rainwater collection, chemical industrial park, runoff pollution, rainwater management