溶解氧对好氧/延长闲置SBR除磷性能的影响

以合成废水为研究对象,乙酸钠为外加碳源,考察不同溶解氧(DO)浓度下好氧/延长闲置(O/EI)序批式反应器的除磷效果,并通过分析典型周期内磷元素及微生物体内各储能物质的变化,探究DO浓度对O/EI工艺除磷性能的影响机制.结果表明,低DO浓度(1 mg·L-1)条件下,O/EI系统具有良好的除磷效果,除磷率高达96%,单位污泥除磷量为5.02 mg·g-1;而当DO浓度较高(4 mg·L-1)时,反应器内磷的去除率降至50%,单位污泥除磷量仅2.81 mg·g-1.研究表明,在DO浓度为1 mg·L-1时,微生物能合成较多聚羟基脂肪酸酯(PHAs),糖原的合成及利用较少,系统好氧吸磷量远高于其他反应器,并在闲置期释放出更多聚磷酸盐.可见,DO可通过影响微生物体内PHAs和糖原的合成及转化,闲置期释磷,好氧前期释磷及好氧吸磷,进而影响系统的除磷性能.

Effect of dissolved oxygen concentration on biological phosphorus removal in oxic/extend-idle sequencing batch reactor

In this study, the effect of dissolved oxygen (DO) concentration on biological phosphorus removal in oxic/extended-idle sequencing batch reactors was investigated, and the influencing mechanism was explored through analyzing the variations of phosphorus and internal energy sources within microorganisms. As a result, the low DO concentration of 1 mg · L^-1 showed a high phosphorus removal efficiency of 96% and a high phosphorus uptake of 5.02 mg · g^-1, while phosphorus removal efficiency decreased to 50% and the phosphorus uptake reduced to 2.81 mg · g^-1 when the reactor was operated at a high DO level of 4 mg · L^-1. The results suggested that microbes can synthesize more polyhydroxyalkanoates (PHAs) under the DO concentration of 1 mg · L^-1, less glycogen synthesis and utilization., Meanwhile, aerobic phosphorus uptake and poly phosphate release in the idle period under the DO concentration of 1 mg · L^-1 are much higher than that in other reactors. DO concentration can affect the phosphorus removal performance of the O/EI system by influencing the synthesis and utilization of intracellular polyhydroxyalkanoates and glycogen, idle phosphorus release, as well as aerobic phosphorus release and uptake.