Research On The Optimization Of Overflow Rain Sewage Treatment Project In Niushan Gulley

Niushan Gulley overflow rain sewage treament project is one of the important projects of Tongsha Reservoir water pollution comprehensive improvement project.Through on-site reconnaissance,the operation and related data are collated.These data are discussed with the water quality of the inlet,outlet and key process nodes.It is shown that there are many problems sush as serious siltation in sedimentation pond,excessive daily water level in storage pond,blocking in subsurface constructed wetland,and poor growth plants in aquatic-plant pond.The runoff water quantity and water quality generated by different rainfall events in the Niushan River catchment area were modeling by SWMM software.The capability of the treatment system to intercept rain sewage pollutants was analysed.It was shown that the capability of settle pond and storage pond is big enough to intercept main pollutants in98.9%rain days.It determined that the scale of the optimized treatment system was in-creased to 10000 m~3/d for well using the treatment capability of the current facility.The de-signed concentration of influent COD,SS,ammonia nitrogen,TN and TP were 80,80,12,21 and 2 mg/L,respectively,in according to the water quality simulating result.Three kinds of alternative processes,including Standard Combination Carbon Carraier filter,Biofilm reactor+Resin system,and Facultative Membrane Bioreactor,were compre-hensively evaluated by Fuzzy Analytic Hierarchy process.It was determined that the STCC process was the recommended technology,according to the evaluating score.The design was Optimized,including adding steel gate bam,desilting the settle pond,building STCC tank,replacing wetland filter and supplementing aquatic plants,to assure that the effluent concentration is stable to match the quasi-class IV in Surface Water Stand-ard(regardless of TN).This optimization research provides a recommended solution for the comprehensive remediation of drinking water sources in Dongguan and technical demon-strations for similar projects.