The implementation unit of a sewage treatment plant in Guangxi is Bicheng Environmental Protection Technology Co., Ltd., a joint venture established by our company and the city investment company, the inlet water is urban domestic sewage, the total sewage treatment is 30,000t/d, and the effluent quality implements the first-class A standard stipulated in the "Pollutant Discharge Standard for Urban Sewage Treatment Plants" (GB18918-2002). The project adopts the AOA technology of Peng Yongzhen, academician of the Chinese Academy of Engineering, which is the world's first and world-leading technology, and is first applied to this project by our company. The AOA process has higher effluent water quality stability, lower investment and operating costs, and a smaller footprint, which can meet more stringent effluent discharge standards in the future, which can effectively carry out advanced treatment and resource utilization of urban sewage, greatly alleviate the overload operation of the original sewage plant, and contribute to the water pollution control of Yichang River and the economic and social development of Cenxi City.
Process flow:
The treatment process of "AOA process + fiber filter cloth filter + tail water ultraviolet disinfection" is adopted, in which the main treatment projects include sewage lifting and pretreatment system (grid, sediment), sewage secondary treatment, sewage advanced treatment, sludge treatment, etc.
AOA Process Advantages:
(1) Make full use of the carbon source in the raw water - most of the COD in the sewage is stored as an internal carbon source for nitrogen removal in the subsequent anoxic stage, and a small part of the COD enters the aerobic zone, in addition, synchronous nitrification and denitrification can occur in the aerobic zone to further utilize the carbon source.
(2) Deep denitrification and high removal efficiency - the AOA process is post-denitrification, which can theoretically achieve close to 100% nitrogen removal effect when the carbon source is sufficient.
(3) Small sludge yield - because most of the carbon sources in this process are used for storage as internal carbon sources for denitrification, and only a small part of the carbon sources are used by heterotrophic bacteria in the aerobic zone, the sludge output of the system is small and the SRT is longer, which can save sludge treatment costs and greatly reduce the cost of sewage treatment.
(4) Energy saving - this process adopts post-denitrification, which does not require a large amount of nitrification liquid reflux, which can greatly save part of the energy consumption used in the reflux sludge. In addition, since the COD is removed in the anaerobic phase, the aeration consumption of the aerobic zone for COD removal is greatly reduced. Most of the dissolved oxygen in the aerobic zone in this process is used for nitrification, and the volume of the aerobic zone only accounts for 25% of the reaction cell. Therefore, the process greatly saves energy consumption for aeration and reflux pumps.
(5) The process is simple - the HRT of this process is 12-16h, and the reaction time is moderate. Only a second set of sludge reflux is added, i.e. sludge is returned to the anoxic zone, and no additional control is required. The process is simple, the operation is convenient, and it is suitable for practical application.
