亚硝酸盐对乳酸发酵缺氧-好氧SBR脱氮系统除磷的影响

在以可溶性淀粉为唯一碳源、进水含有硝态氮的缺氧-好氧SBR脱氮除磷系统中,研究了投配亚硝态氮对该乳酸发酵系统除磷的影响.试验结果显示,初始投加亚硝酸盐的浓度分别为2、5、10 mg·L~(-1)时对系统的缺氧吸磷及好氧吸磷都产生了抑制作用,缺氧阶段的释磷量和释磷速率随进水亚硝酸盐浓度的增大而升高.亚硝酸盐对缺氧期液相中乳酸和污泥中糖原的积累都有明显的影响,当亚硝酸盐浓度由0 mg·L~(-1)升至10 mg·L~(-1)时,乳酸浓度由14.06 mg·L~(-1)下降至1.56 mg·L~(-1),相反污泥中糖原的含量从235.69 mg·g~(-1)上升至272.97 mg·g~(-1)(以VSS计,下同),并且在好氧阶段糖原的消耗量增加,污泥的吸磷量也随之增加.研究表明,亚硝酸盐对淀粉直接发酵成乳酸的过程及糖原转化为乳酸的过程均有抑制作用.

The effect of nitrite on the phosphorus removal in anoxic-aerobic SBR system with lactic acid fermentation

In an anoxic-aerobic SBR system, the effect of nitrite on biological phosphorus removal, with soluble starch as the sole carbon source, was investigated. The results show that the nitrite of initial concentration of 2, 5 and 10 mg·L^-1 respectively inhibited anoxic and aerobic phosphorus uptake. The phosphorus release capacity and phosphorus release rate in anoxic stage increased with increasing nitrite concentration. In this study, the accumulation of lactic acid in liquid phase and glycogen in sludge were influenced significantly by nitrite during the anoxic phase. When nitrite concentration increased from 0 mg·L^-1 to 10 mg·L^-1, concentration of the lactic acid decreased from 14.06 mg·L^-1 to 1.56 m·L^-1, but the content of glycogen increased from 235.69 mg·g^-1 to 272.97 mg·g^-1. When the consumption of glycogen increased in aerobic stage, the amount of phosphorus uptake in the sludge increased. It is suggested that nitrite inhibited the conversion of starch and glycogen to lactic acid.