Process Optimization And Large Scale Experiment On Advanced Wastewater Treatment In Harbin

In the past decades, the Songhua River in Harbin for drinking water havebeen more and more polluted by municipal sewage and industry wastewater, andbeen upset the people along the river. It is not enough to depend only onsecondary treatment ratio, but no consideration about recycle the waste water asreclamation water to hold the health of water cycle together, at the same tine tobe a new important part of city source water. Then we can see a bright future forthe healthy water cycle in garden city at hand.Biofilters in regeneration, decontamination efficiency and effectionmechanism at low temperature have been studied in Harbin, Da Lian, Bao Dingand Shen Zhen. The conclusions as follow: The removal efficiency bybiofiltration is better than the rapid fiters, which the removal of COD,BOD5,turbidity,NH4 -N can increase by 25.7%, 54%, 43%, 62%. The optimumhydraulic load, DO and pH were 6~8m/h, 1.5~2.5mg/L, 7~8 separately, but theoptimun operation cycle depended on the influx water quality and temperature.To test the trials, pilot experiment shows: wastwater completed treatmentflow consisting of primary, secondary, and advanced treatment could reflect thereal operation efficiency and obtain the fitable run parameter. The properbackwashing and controlling autotuaph and heterogeneous bacteria canaccelerate the start-up process. The fitable values of volume load, hydraulic load,DO are 8Kg/m3·d, 7m3/m2·h, 1.5~2.5mg/L for the biofilters in advancedwastewater treatment. The COD removal quantity was about 2.2Kg/m3.d when P Phydraulic load was more than 9m3/m2·h, but it doesn't matter with volume load.In the operation parameters aspect, static beaker test shows: comparing withthe aluminium sulfate, PAC, and PAM, we choose aluminium sulfate ascoagulation medicament. The injection quantity of reagent was about 1.5~1.6time than the beaker test. The optimum water to gas ratio is about 1.07 in airflotation pond. The influx load is 3.0 m3/m2·h when the filter reach its bestoperation condition, the filter cycle time is 48 hours at that time. The optimumoperating parameters of common package through three-phase combinedbackwashing manner are as follow: air backwashing intensity is 14 L/s·m2, water P...