The Application Of Biological Aerated Filter Technology In Ba-baishang Sewage Treatment Plant Of Daqing City

As the national economy and healthy development of national urban construction and social undertakings in the rapid development of urban infrastructure reconstruction, economic development zone, residential area development and construction of large commercial construction projects, so that sewage emissions increase every year. For dealing with sewage treatment facilities continue to build.However, the field of water pollution control in China, built the existing sewage treatment plant (station), especially in urban sewage treatment plants are mostly of traditional activated sludge method and its deformation process, oxidation ditch, AB process, SBR process and so on. Although the processing system can still be even better, but the widespread area of large, high investment in infrastructure, processing load is low, running start slowly, often sludge bulking, not withstand shock load and other shortcomings, while process devices with low processing performance, high energy consumption, low efficiency can not meet the requirements.Biological aerated filteris a late 20th century, 80 developed in Europe and the United States is a new wastewater treatment technology, as it overcomes the activated sludge covers an area of large, easy to distribute and run the non-ozone stability and other shortcomings of concern. BAF main advantages are as follows: small footprint, only conventional secondary biological treatment of 1 / 10 to1 / 5; water quality high, BAF effluent treatment not only meet environmental emissions standards, and can be used for water reuse; BAF No set up the secondary settling tank and sludge return pumping stations, infrastructure costs and low running costs, BAF's infrastructure costs and operating expenses significantly lower than with conventional secondary treatment technology costs; management convenience, BAF implemented computer-controlled, not only including the operation of automatic control equipment, and operational data enables online display. High reliability, BAF shock resistant capability, without bulking problem, not running for some time (a few days or months), micro-organisms will not be lost, can be restored to normal within a few days the level of treatment; BAF odorless and noise generated.Its modular structure is conducive to change the future Construction.Ba-baishang sewage treatment plant using post-denitrification BAF process, through two biological aerated filter and water treatment plant and out of the water quality data study, the following conclusions:(1) an aeration tank to the higher COD removal efficiency, 60% to 79%, the average removal rate of 70%. While the NH4+-N removal rate of low 10% to 28% average of only 18.9%; two aeration tanks of the NH4+-N removal is quite obvious, the average removal rate of up to 72.1%, and the effluent NH4+-N values full compliance with emission standards at the national level B (maximum effluent value 12mg / L), while the COD removal rate of 13% to 40%, the average removal rate was only 22.6%.(2) water temperature on COD removal rate significantly affected, with the effluent water temperature gradually increased, COD removal .Water temperature 20℃to 25℃time, COD removal efficiency, the average removal rate was 78%. Water temperature 3℃to 4℃, the process on the removal rate of only 61%; water temperature above 15℃, temperature has little effect on the removal of ammonia nitrogen removal rate remained at 79% to 84% . But the water temperature below 10℃, the removal rate of 63% to 70%.(3) the year 2009, wastewater influent BOD concentration 180 mg / L and 246 mg / L between, BOD removal rate remained at 90% to 94.4%; COD influent concentration fluctuations, and a minimum of 316mg / L, maximum 505 mg / L, but the COD removal rate remained at 84.8% to 95.7%. And effluent COD, BOD concentrations were lower than the national sewage discharge standard B (60 mg / L, 20 mg / L), can be seen the capacity of the system very strong resistance to impact load. And the system runs very stable, even in winter, even under low temperature to maintain a high removal rate.(4) the year 2009, wastewater influent ammonia nitrogen concentration of 27mg / L to 55 mg / L, removal efficiency remained at 64.7% to 93.5%, the average removal rate was 84.46%, the effluent concentrations were 15 mg / L the following, to the national sewage discharge standard B. Therefore, this process uses denitrification filter + Biological Aerated Filter, has a good handle on the effect of ammonia nitrogen, total water discharge are entirely up to the national level B standards.Biological Aerated Filter technology has been rapid development in China, but the actual operation there are still many problems need to improve the future design of the study:(1) under low temperature environment than carbon, nitrifying bacteria and denitrifying bacteria have a greater impact, affecting water quality. In the design of future environmental temperature is lower when dealing with when considering laying in the pool wall heating tubes or hot air aeration and other methods to improve response to water temperature, increased COD, BOD and ammonia nitrogen treatment effect.(2) single-hole membrane aerator oxygen utilization rate is higher, can reduce the energy consumption of the disadvantage of high cost, large equipment, installation complexity, aeration and air pipe junction easily damaged, if the damage occurred leakage cut-off filter pulls out required maintenance of aeration system will seriously affect the normal operation of the sewage plant, also increased equipment maintenance costs. Thus R & D investment, low failure rate, easy maintenance, the new aerator become part of the research focus.(3) without making the paper adding chemicals combined use of phosphorus and organic matter removal BAF system, SS and nutrient side Surface studies, domestic and international studies conducted in this area are few. China should carry out research in this area, to cost-effectively solve the increasingly serious eutrophication phenomenon.(4) Biological Aerated Filter technology has the advantages of its management simple, but because of the complexity of its operations can not be done manually, with automatic control system must complete a series of complex operations. Home automation control software in the emergency treatment and rapid feedback, etc. to be improved, therefore should enhance the automated control system in a sewage treatment plant and research and development.