Haoyan Liu

The main hindrance to implementation of domestic sewage treatment plant-network integration in China is the separated assessment method. The assessment method of plant-network integration links payment for sewage treatment to incoming pollutants, and payment for maintenance of the pipe network to the concentration of pollutants in incoming water. It helps establish an interactive link between the city and district, and motivates operation and management stakeholder groups. The method contains index system formulation, target value determination, assessment payment plan specification and city-district payment proportion clarification. It provides a solution for the current drainage management by promoting plant-network integration.

External water (such as rainwater, mountain water and groundwater) will decrease the inflow contaminant concentration in urban sewage plants, and pose challenges in improving the wastewater treatment quality and efficiency. Therefore, removing the external water is vital for this target. A sewage plant in Zhuhai, China, was considered as an example. By performing online flow monitoring, water quality testing, on-site survey and data analysis, the rainfall-derived inflow and infiltration of the sewage system were quantitatively analysed through the pollutant balance method. By proposing key emphases of severe problems, the presented findings will aid in sewage system maintenance and pipeline network renovation.