硝酸盐作为生物除磷电子受体的研究

Study of Using Nitrate as Electron Acceptor in Biological Phosphorus Removal

研究了以硝酸盐作为电子受体进行生物除磷的可能性 ,并比较了硝酸盐和氧作为电子受体的差异。结果表明 :聚磷菌能以硝酸盐作为电子受体替代氧进行生物除磷 ,但若存在有机碳源会抑制缺氧段磷的吸收。缺氧条件下磷的摄取速率与硝酸盐的质量浓度有关 ,浓度越高速度越快。硝酸盐的连续稳定加入有利于磷的去除。与以氧为电子受体的系统相比硝酸盐系统利用PHA的效率低 ,缺氧系统中去除磷和消耗PHA的比例为 0 63 ,比好氧系统中的 0 83低 2 4% ;缺氧时每摩尔电子转移所吸收的磷为 0 14mol,比氧为电子受体时的 0 2 3mol低 3 9 1%

The possibility of using nitrate as electron acceptor in biological phosphorus removal was studied in this paper,and the difference between nitrate and oxygen as electron acceptor was compared. The results indicated that polyphosphate accumulating organisms (PAOs) could use nitrate as electron acceptor for biological phosphorus removal instead of oxygen,but it would be inhibited if COD presented.The rate of taking up phosphate in anoxic stage was related to the concentration of nitrate:the higher the concentration of nitrate was,the higher rate of taking up phosphate was obtained.The continuous and steady addition of nitrate is of benefit to phosphate removal.The efficiency of PHA digestion in the system using nitrate as electron acceptor is lower than using oxygen.The ratio of removed phosphorus to consumed PHA under anoxic condition was 0 63,which was 24% lower than 0.83 under aerobic condition;the amount of phosphorus taken up to per mole of electrons transferred under anoxic condition was 0 14 mol,which was 39 1% lower than 0 23 mol with oxygen as the electron acceptor.