【摘要】 以除磷颗粒污泥为研究对象,采用批次试验,以混合丙酸和乙酸(2∶1)为外加碳源,在厌氧起始阶段投加不同浓度的NO3--N(0,20,30,50和75mg.L-1,pH=8.0)和NO2--N(10,20,40和60mg.L-1,pH=7.0,7.5和8.0),研究缺氧环境对颗粒污泥强化除磷系统释磷的影响。结果表明,硝态氮的投加对聚磷菌释磷无明显抑制,系统中VFA的吸收、磷的释放和硝态氮的反硝化同时发生,挥发性脂肪酸(VFA)吸收速率增大但比释磷速率降低,主要原因是反硝化菌与聚磷菌竞争碳源。不同pH和不同浓度的NO2--N批次试验表明,游离亚硝酸(FNA)对磷的释放有明显刺激作用。当FNA增加到0.004mg HNO2-N.L-1,比磷释放速率增加了4倍。另外,FNA对VFA的吸收和PHA的合成均有明显抑制,分别减少了53%和70%。从聚磷菌的产能代谢和对细胞的毒害作用的角度分析,FNA刺激磷释放的机理是在游离亚硝酸存在的情况下,聚磷菌需要释放更多的能量来保持足够的质子驱动力。更多还原

【Abstract】 In order to study the effects of anoxic condition on release of phosphorus in an enhanced system for phosphorus removal with granular sludge,batch tests were carried out using acetate and propionate(carbon molar ratio=2∶1)as carbon source and adding different amount of NO-3-N(0,20,30,50 and 75 mg·L-1,pH=8.0)and NO-2-N(10,20,40 and 60 mg·L-1,pH=7.0,7.5 and 8.0)in initial anaerobic stage.The results showed that addition of NO-3-N and NO-2-N had no obvious inhibition on release of phosphorus.Absorption of fatty acids(VFAs),phosphorus release and denitrification took place simultaneously,and absorption rate increased while release rate of phosphorus decreased because of competition between denitrifying bacteria and phosphorus accumulating microbial granule(PAOs)for carbon source.The results of batch tests at various NO-2-N concentration and at different pH showed that FNA,rather nitrite,had a strong stimulation effect on P-release and the rate of P-release increased by 4 times when FNA concentration was higher than 0.004 mg HNO2-N·L-1.Meanwhile,FNA had obvious suppression on absorption of VFA and synthesis of PHA,and the absorption rate and synthesis mass decreased by 53% and 70%,respectively.Based on analysis of energy generation and metabolism of PAOs as well as toxic action of nitrite,the mechanism stimulating P-release of FNA was,in presence of free nitrous acid,that PAOs was required to release more energy to provide adequate proton motive force(pmf).更多还原