不同电子受体影响下的反硝化除磷过程

为进一步了解反硝化除磷菌的代谢行为,以序批式反应器(SBR)在厌氧/好氧条件下培养的活性污泥为对象,进行批次试验,研究了不同电子受体对反硝化缺氧吸磷的影响.结果证实:只要有电子受体存在,不论是硝氮(NO3--N)还是亚硝氮(NO2--N),缺氧吸磷都会发生,但NO2--N的缺氧吸磷量相对较少;反应开始时的电子受体质量浓度对反应过程影响很大,试验中NO3--N质量浓度为30mg/L、NO2--N质量浓度为20mg/L时吸磷量和吸磷速率均达到最高值;低于该值时,吸磷量和吸磷速率随着电子受体质量浓度的提高而增加;高于该值时,吸磷量和吸磷速率随着电子受体质量浓度的提高而减少;NO2--N质量浓度达80mg/L时,没有发现对反应的抑制作用;好氧吸磷效果好于缺氧吸磷.试验还发现反应器在厌氧/缺氧条件下连续运行时,反硝化除磷菌的厌氧释磷和缺氧吸磷能力将很快丧失.

Denitrifying Phosphorus Removal Affected by Different Electron Acceptors

In order to obtain a better insight into the metabolic behavior of denitrifying phosphorus-removing bacteria,the effects of various types of electron acceptors on the denitrifying anoxic phosphorus uptake were investigated.Then,batch experimental tests were carried out using the activated sludge cultivated in a sequencing batch reactor(SRA) in anaerobic/aerobic condition.The results indicate that(1) anoxic phosphorus uptake occurs when there exists an electron acceptor,be it nitrate or nitrite;(2) as compared with nitrate,nitrite results in a relatively small amount of anoxic phosphorus uptake;(3) the initial mass concentration of the electron acceptor has great effect on the reaction;(4) the amount and rate of phosphorus uptake reach their maximum values when the mass concentrations of NO-3-N and NO-2-N are respectively 30 and 20 mg/L;(5) with the increase in the initial mass concentration of electron acceptor below or more than the optimal value,the amount and rate of anoxic phosphorus uptake increase or decrease accordingly;(6) the nitrite with a content of 80 mg/L has no inhibition to the phosphorus remo-val process;and(7) the denitrifying phosphorus-removing bacteria may rapidly lose their ability of phosphorus release and uptake in continuous anaerobic/anoxic condition.