On The Design And Treating Effect Of AAO-Bio-Contact Oxidation Integrated Treatment Plant For Rural Domestic Sewage

Chinese rural domestic sewage has the characteristics of large and scattered sewage,and it is difficult to achieve centralized treatment.At this stage,most of the rural domestic sewage is directly discharged or treated in simple constructed wetlands and septic tanks.The degree of domestic sewage treatment is low,which is very important for nearby river basins.Water quality and soil quality have a greater impact.However,due to the limited funds for rural construction,the scattered population and the difficulty of pipe network construction,the traditional centralized sewage treatment technology is not suitable for promotion and use.Therefore,researching and designing rural domestic sewage treatment technologies and devices with high treatment efficiency,strong practicability,and easy operation,maintenance and management can provide theoretical and technical support for the promotion and industrialization of rural domestic sewage treatment technologies,and has certain practical significance.This research combines the advantages of AAO treatment technology and contact oxidation treatment technology to form an integrated domestic sewage treatment device with AAO-biological contact oxidation process as the core treatment technology.From the design and start-up of the integrated treatment device,the best The experimental research was carried out from the perspectives of determining operating parameters,operating treatment effects under low temperature conditions,and treatment effects of different fillers,and obtained the following research results.(1)By comparing the requirements and applicability of different integrated domestic sewage treatment technologies,the main process design of the integrated rural domestic sewage treatment device was completed.In the start-up phase of the test device,the natural inoculation method was adopted,and the biological rope filler was inoculated for 15 days.The growth of the biofilm on the surface of the filler was good,and the effluent quality was stable.The microscopic examination showed that the filling biofilm microorganisms gradually formed a complete biological chain from bacteria,protozoa to metazoa in time sequence.The indicator microorganisms were used to judge the processing capacity of the biofilm and the sludge condition,and the test device was started.(2)Determine the best parameters of hydraulic retention time(HRT),aeration volume,aeration method and phosphorus removal agent addition,and carry out long-term monitoring of the influence of water temperature parameters on the operation effect of the integrated domestic sewage treatment device.Comprehensive analysis of the test results and economic indicators,etc.,determine the best operating parameters of the rural domestic sewage AAO-contact oxidation integrated treatment device: HRT is about 9 h,intermittent aeration method is adopted,and the aeration rate is 15L/min.Phosphorus agent PAC dosage is about50-60 ppm.The test device runs under this optimal control parameter,the removal efficiency of sewage pollutants is high,the effluent water quality is relatively stable,and the operation treatment effect is better.(3)Comparative analysis of the treatment efficiency of different materials and properties of membrane biological fillers.And reflect the growth of biofilms of different fillers through stable operation.The traditional nylon rope packing has a long time to hang the film,the speed is slow,the material is easy to corrode,and the installation density of the biological rope is small,the membrane biomass is insufficient,and the impact resistance is poor.MBBR filler has a fast film forming speed and shows excellent processing capacity,but it is difficult to operate in an integrated device,the device structure is complicated,and it is difficult to maintain.It is more suitable for use in small sewage treatment stations or sewage treatment plants.The polyester rope filler has a large specific surface area,strong water retention capacity,fast film forming speed,and excellent treatment effect.It is more suitable for use in an integrated sewage treatment device.