Water Quality-Based Double-Gates Control Strategy for Combined Sewer Overflows Pollution Control

The combined sewer overflows (CSO) pollution has caused many serious environmental problems, which aroused a worldwide concern. Traditional interception-storage measures, exhibit the disadvantages of larger storage tank volume and low concentration, cannot efficiently control CSO pollution. To solve this problem, water quality-based double-gate strategy based on real-time (PBRTC) rule was proposed, chemical oxygen demand (COD) concentration taken as index. A case study carried out in Fuzhou, China an example, hydraulic quality model were constructed to evaluate two schemes. According results, compared traditional scheme, scheme can not only reduce by 1515 m3, but also increase average COD interception rate 1.84 times, thus ensuring effective stable operation facility. Furthermore, evaluated under design rainfall beyond return period, confirmed high performance controlling