污水处理厂提标改造关键技术与工程实践

Key technologies and engineering practices for upgrading and renovating sewage treatment plants

河北省某市政污水处理厂一、二期工程规模均为3.0×10^(4)m^(3)·d^(-1),原采用以“水解酸化池-连续进水周期循环曝气活性污泥系统(CASS池)-臭氧接触氧化池”为核心的处理工艺。由于该污水处理厂运行时间较长、周边城镇污水收集量不断上升,以及排放标准有所提高,导致该污水处理厂的处理能力相对不足,出水水质无法达标。经多方工艺论证,并结合用地限制、运行现状和经济指标等因素,针对生化需氧量(BOD5)、化学需氧量(CODcr)、氨氮(NH3-N)、总氮(TN)以及总磷(TP)等指标,对该污水处理厂的生化处理部分采用水解酸化池改造为厌/缺氧池,并在厌/缺氧池内增加弹性填料的提标改造措施,深度处理部分采用臭氧接触氧化池改造为臭氧催化氧化池的提标改造措施,并对工艺调试期间各主要处理单元的进、出水水质进行了分析。结果表明,提标改造后的污水处理系统运行良好,具有污染物去除率高、处理效果稳定、抗冲击性强等优点,CODcr和TP的排放浓度分别降低至20 mg·L^(-1)和0.2 mg·L^(-1)以下,出水水质稳定达到《地表水环境质量标准》(GB 3838-2002)中Ⅲ类水标准,同时达到《大清河流域水污染物排放标准》(DB 13/2795-2018)中核心控制区排放限值。该研究结果可为类似污水处理厂的提标改造提供理论参考。

The Phase I and Phase II projects of a municipal sewage treatment plant in Hebei Province each have a capacity of 3.0×10^(4) m^(3)·d^(-1).The core treatment process consists of a"hydrolysis acidification tank"followed by a"continuous inflow cycle circulation aeration activated sludge system(CASS tank)"and an"ozone contact oxidation tank."Due to the extended operation time of the sewage treatment plant,the continuous increase in sewage collection volume in surrounding towns,and the improvement of discharge standards,the treatment capacity of the plant was relatively insufficient,and the outlet water quality cannot meet the required standard.After multiple process demonstrations,and considering factors such as land restrictions,operational status,and economic indicators,the targeting indicators included biochemical oxygen demand(BOD5),chemical oxygen demand(CODcr),ammonia nitrogen(NH_(3)-N),total nitrogen(TN),and total phosphorus(TP).The biochemical treatment section of the sewage treatment plant was converted from a hydrolysis acidification tank to an anaerobic and anaerobic tank.And an improvement measure was implemented by adding elastic fillers to the anaerobic and aerobic tank.The advanced treatment section was converted from an ozone contact oxidation tank to an ozone catalytic oxidation tank.An analysis was conducted on the inlet and outlet water quality of each primary treatment unit during the process debugging period.The results showed that the upgraded and renovated sewage treatment system operates effectively,demonstrating advantages such as a high pollutant removal rate,stable treatment effect,and strong resistance to impact.The discharge concentrations of CODcr and TP were reduced to below 20 and 0.2 mg·L^(-1),respectively.The effluent water quality stably met the Class III water standard in the Surface Water Environmental Quality Standard(GB 3838-2002).It also met the emission limits of the core control area in the Daqing River Basin Water Pollutant Discharge Standard(DB 13/2795-2018).The research results can provide theoretical references for the upgrading and reconstruction of similar sewage treatment plants.