膜生物反应器中有机营养物对污泥活性的影响特性

ACCLIMATION BEHAVIOR OF ORGANIC NUTRIENTS TO ACTIVATED SLUDGE IN MEMBRANE BIOREACTORS

试验研究了以葡萄糖为代表的典型非毒性有机营养物对硝化过程的影响,结果表明:在低浓度葡萄糖驯化活性污泥条件下,硝化菌富集效果明显,污泥中硝化菌的活性逐渐上升;而高浓度葡萄糖驯化环境下,硝化菌的活性受到高浓度有机营养物的抑制作用,但异养菌的活性逐步提高。说明:在连续MBR驯化条件下,由于有机营养物可以迅速为异养菌所分解利用,异养菌的快速增殖将对硝化菌的活性形成竞争性的抑制作用;但随着时间的延长,由于膜对溶解性难降解的有机大分子的有效截留和污泥长时间没有更新,污泥中无论硝化菌还是异养菌,其活性都将逐渐地降低。

The influence of glucose, as a typical non-toxic organic nutrient to the microbes in activated sludge, on the nitrifying process is investigated. The results showed that the nitrifying activity increased gradually at low concentration level of glucose,while decreased sharply at high concentration of glucose, along with an enhanced activity of organic-utilizing bacteria (heterotrophic bacteria ). It indicates that when plentiful organic carbon was added to influent water, the heterotrophic bacteria seems to reproduce and grow rapidly, whose growth rate was higher than that of nitrifying bacteria, and its number becomes dominant in the whole microbe of activated sludge to enhance the activity of organic compounds utilization, which probably inhibited the activity of nitrifying bacteria. But a slow declination to the activities both for nitrifying bacteria and heterotrophic bacteria was observed as time lapsed.It explain that the accumulation of dissolved-and-high-molecular organic compounds captured by the membrane and no sludge renewal occurred timely due to the longer sludge retention time than the usual were considerably responsible for the results mentioned above.