Direct Sewage Conceration By Hybrid Coagulation-adsorption-based System

The sewage treatment process is now unable to meet the requirements ofsustainability concept, for its high energy consumption, and CO2emissionscharacteristics. As people deepen understanding of environmental issues，Sewagetreatment process to achieve a comprehensive resource will become the future trend.Anaerobic technology as a more mature technology meets the requirements ofcomprehensive resource for its high characteristics of realize the recycling of organicenergy and nutrients. However, the biggest obstacle to the effective use of anaerobictechnology is the low concentrations of sewage. So the key step of achievecomprehensive sewage recycling and resource recovery.Using physical-chemical treatment sewage concentration is the best option forminimize the loss of organic energy by biological processes. This study proposes tworoutes to achieve sewage concentrate，coagulation-adsorption pretreatment combinedsedimentation separation，and coagulation-adsorption pretreatment combined filteredfor sewage concentrated, and designs two kinds of reactors (upflow sludge layer reactorand double-layer-filter dynamic membrane reactor) to validate the possibility of thistechnique route. Firstly, according to the quantity of the influent, select the suitablecoagulant and adsorbent and have a short discuss on the mechanism of thecoagulation-adsorption process. It concluded that the best removal efficiency was getwhen concentration of PAC and powder activated carbon were60mg/L and40mg/lseparately and the diatomite has the ability of coagulation and adsorption. Thecoagulation and adsorption process remove the organic substrate from wastewater tosolid phase and benefit for the separation and concentration.By the experiments of upflow sludge layer reactor, it concluded thatcoagulation-adsorption filtration of sewage wastewater was feasible and the optimumparameters were gained from experiments. The COD removal efficiency was around80%and SCOD removal efficiency was during40%and50%. During the short cycle time(one SRT), about the64.6%percent of COD was concentrated,19.6%in effluent and15.8%for bacteria use.By the experiments of double-layer filter dynamic membrane, it concluded thatcoagulation-adsorption filtration of sewage wastewater was feasible. After70h, theCOD of concentrated sewage increased from615mg/L to4500mg/L. about the70.7%percent of COD was concentrated in the reactor,44%in the concentrated sewage and26% loss perhaps for the degradation of bacteria or adsorption in the reactors. In theoperation, the main pollution of membrane was from cake layer, little from gel layer.And the flux of membrane can resume after physical washing.