Application Study Of Reuse And Circulatory System For Domestic Sewage

According to the quality characteristics and discharge features of residential sewage,the advantages and disadvantages of several major sewage treatment methods werecompared. A combined microfiltration process was selected finally. A small pilot test wasimplemented and the process parameters were optimized. Every processing unit wasintegrated to build a reuse system of wastewater. The system provides reference formanufacture residential sewage reuse system.The pilot test focused on residential sewage treatment with membranebioreactor-ozone. MBR was inoculated with similar activated sludge. After two cycles ofthe start-up test, the COD of membrane effluent and the removal rate of ammonia nitrogenwere75.3%and54.5%, respectively. During the running, COD and ammonia nitrogenremoval rates were75.3%~92.3%and53.3~98.1%, respectively. The activity of MBRsludge performed better, the protozoa could be observed through microscope. Themembrane flux decreased from51.62L/(h·m2·m) to20.38L/(h·m2·m), Membrane effluentturbidity was0.08~0.43NTU. Ozone can disinfect the pathogenic bacteria in themembrane water and ensure the quality of water meet the requirements of urban recyclingwater quality in urban miscellaneous water (GB/T18920-2002).With the process and product design, a prototype of wastewater reuse system wasfabricated with3m3/d scale. The device is divided into biological treatment units, filmprocessing unit and disinfection unit. Sewage flows into three units in turn to purification.The equipment investment was about39,000RMB, with the construction cost13,000RMB/m3treated water and the running costs is about7.5RMB/m3treated water. Themodule of product units was defined, and then the structure of the product was determinedthrough the shape research. The biological treatment and membrane separation module wasdefined as well, adopting column mode module according to the technical characteristics.It plays a fundamental role in further production, the product seriation and standardization.The combined microfiltration process was utilized to treat residential sewage, thewater quality standards and the requirements of reuse were achieved. Successfuldevelopment and application of the new combination create a new field for wastewatertreatment and reuse, which explores new ideas to the production, sales and applications ofintegrate equipment.