以亚硝酸盐为电子受体的反硝化除磷性能研究
Study of the Characteristics of Denitrification Phosphorus Removal Using Nitrite as Electron Acceptor
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摘要: 以实际生活污水为研究对象,在SBR系统中采用厌氧/缺氧运行方式,考察不同亚硝酸盐(NO2--N)质量浓度下以亚硝酸盐为电子受体的反硝化除磷性能.实验根据进水ρ(COD)及亚硝酸钠投加量的不同,分为3个阶段.研究发现,维持缺氧段初始ρ(NO2--N)为20mg/L左右(第Ⅲ阶段),经过长期驯化,运行稳定后,缺氧段吸磷率达74.42%,最大吸磷速率可达11.70 mg/(gMLSS·h);磷去除率达57.8%.此后,又进行了初始ρ(NO2--N)为50 mg/L的亚硝酸盐冲击负荷试验,缺氧段最大吸磷速率为5.63 mg/(gMLSS·h),与第Ⅲ阶段相比,最大吸磷速率下降53%.随后在未经驯化的情况下,通过短期实验分别考察该系统以NO3--N和O2作为电子受体时的除磷性能,其缺氧段最大吸磷速率分别为11.09和29.268 mg/(gMLSS·h),分别是第Ⅲ阶段最大吸磷速率的94.7%和2.5倍.Abstract: A SBR process was adopted to investigate the characteristics of denitrification phosphorus removal by using nitrite as electron acceptor and treating real domestic wastewater.An anaerobic/anoxic method was introduced in the process,and nitrite was dosed at the end of anaerobic phase.According to the different level of influent COD and the dosed nitrite,the experiment can be separated into three phases.At the third phase,keeping nitrite at 20 mg/L,after a long tern domestication,the max phosphorus uptake rate raised to 11.70 mg/(gMLSS·h) in the anoxic phase,and 74.7% of released phosphorus was up-taken,while the 57.8% of phosphorus was removed from the system.Taking a shock load experiment by raising the initial concentration of nitrite to 50 mg/L,the max phosphorus uptake rate was only 5.63 mg/(gMLSS·h),decreased 53% compared with the third phase.By investigating the impact of different electron acceptor(NO3--N、O2) to the system,the max phosphorus uptake rate was 11.09 and 29.268 mg/(gMLSS·h) respectively,which was 94.7% and 2.5 times of the third phase.