SBR短程脱氮系统中亚硝酸盐积累对生物除磷的影响  

Effect of nitrite from short-cut nitrification on biological phosphorus removal in an SBR process treating domestic wastewater

作　　者：曾薇[1] 杨莹莹[1] 李磊[1] 王向东[1] 彭永臻[1] 

机构地区：[1]北京工业大学,环境与能源工程学院,环境工程研究所,北京100124

出　　处：《环境科学学报》2011年第2期236-244,共9页Acta Scientiae Circumstantiae

基　　金：国家自然科学基金资助项目(No.50878005);北京市自然科学基金资助项目(No.8102005);霍英东教育基金会高等院校青年教师基金(No. 121076)~~

摘　　要：采用SBR工艺处理实际生活污水,通过控制好氧段的DO浓度及曝气时间,实现了短程硝化反硝化,并考察了短程硝化引起的亚硝酸盐积累对生物除磷系统的影响.结果表明,在没有补充外碳源的情况下,好氧阶段NO2-N的积累低于10mg·L-1时,聚磷菌的吸磷及放磷能力没有受到影响,好氧出水磷浓度基本维持在1mg·L-1以下;当NO2-N浓度达到20mg·L-1时,好氧出水磷酸盐浓度升至5mg·L-1左右,聚磷菌的释磷量和吸磷量明显下降,系统除磷性能恶化.向系统中投加碳源(初始COD200mg·L-1),20d后除磷性能恢复.经分析,好氧阶段高达25～30mg·L-1的亚硝酸盐积累并没有对聚磷菌好氧吸磷产生抑制作用.除磷性能恶化的主要原因是一定浓度的亚硝酸盐进入厌氧段,反硝化菌与聚磷菌竞争碳源,碳源不足时导致聚磷菌合成聚羟基烷酸(PHA)的量减少,好氧吸磷量随之减少,最终导致系统除磷性能恶化.亚硝酸盐对聚磷菌厌氧代谢影响的静态批次试验表明,作为一种抑制剂,高达30mg·L-1的亚硝态氮没有对聚磷菌的厌氧释磷产生抑制;碳源充足情况下,30mg·L-1的亚硝态氮对聚磷菌合成PHA没有影响,但在碳源不足的情况下,厌氧段反硝化引起的碳源竞争导致聚磷菌PHA合成量和释磷量减少.A lab-scale anaerobic/aerobic sequencing batch reactor （SBR） was operated to investigate its performance in biological nutrient removal from domestic wastewater,particularly regarding the effect of nitrite accumulation resulting from short-cut nitrification on biological phosphorus removal （BPR）. Short-cut nitrification was successfully achieved by controlling low DO concentration （0.5~1.0 mg·L^-1） and aerobic duration. The results showed that less than 10 mg·L^-1 of nitrite had no effect on phosphate uptake and release with PO3-4-P concentrations in the aerobic effluent of below 1 mg·L^-1; whereas a significant decrease of phosphate uptake and release with the effluent PO3-4-P concentration of 5 mg·L^-1 was observed when nitrite accumulation reached 20 mg·L^-1,indicating deterioration of BPR. After adding external carbon sources （initial COD concentration of 200 mg·L^-1）,BPR performance recovered after 20 days. The results suggest that the 25~30 mg·L^-1 of nitrite accumulated during the aeration period did not inhibit aerobic phosphate uptake. The main reason for poor phosphorus removal was that the presence of nitrite in the anaerobic period caused denitrifying bacteria to compete with phosphate accumulating organisms （PAOs） for limited carbon sources. Lowered poly-β-hydroxyalkanoate （PHA） synthesis in PAOs led to decreased phosphate uptake in the aerobic stage. Batch experiments were performed to investigate the effect of nitrite on PAOs under anaerobic conditions,which indicated that nitrite as an inhibitor at a concentration of 30 mg·L^-1 would not inhibit the anaerobic phosphate release. When sufficient carbon source was provided,nitrite of 30 mg·L^-1 had no impact on PHA storage; contrarily,when the carbon source was insufficient,denitrifying bacteria competing for carbon source with PAOs resulted in a decrease of PHA synthesis and phosphate release.

关 键 词：亚硝酸盐 短程硝化 聚磷菌 生物除磷 生活污水 

分 类 号：X703.1[环境科学与工程—环境工程]