无排泥运行下膜生物反应器的硝化代谢产物及细菌活性

采用膜生物反应器处理人工配制的无机NH₄⁺-N废水,在NH₄⁺-N浓度为500mg/L、无排泥条件下运行200d(HRT从30h逐步降至7h),系统内污泥浓度从最初的4 500mg/L上升至10 500mg/L.但是,单位污泥中以INTF吸光值表达的活性硝化菌数并未增加,从最初的23×10^-3降至1×10^-3;总NH₄⁺-N转化速率也从2.1kg/(L·d)降至1.5kg/(L·d).同时,反应器中胞外分泌产物(ECP)(糖和蛋白之和反应)从300 mg/L升至600mg/L. 利用上清液以及ECP提取液进行的批量试验结果表明,ECP过多抑制了硝化细菌活性.

Activity of Nitrifiers and Metabolized Products in a Membrane Bioreactor MBR Under the Condition of Non-Sludge Discharge

A membrane bioreactor fed with synthetic ammonium bearing inorganic wastewater was operated under the following conditions: HRT, from 30h to 7h; influent NH₄⁺-N, 500mg/L; non-discharge of sludge. Formation of extra-cellular polymers (ECP) and their influence on the activity of nitrifiers in the membrane bioreactor was investigated. Over the whole experimental period of 200 d, the activity of nitrifiers in terms of overall ammonium-oxidizing rate decreased from 2.1kg/(L·d) to 1.5kg/(L·d), and the nitrifier number using INTF absorbency measurement decreased from 0.023×10^-3 to 0.01×10^-3, although the MLSS increased from 4 500mg/L to 10 500mg/L. The ECP content increased from the initial 300 mg/L to 600mg/L. Batch tests using the extracted ECP also indicated that the activity of nitrifiers could be inhibited by the existence of ECP.