化学物质对硝化细菌的选择性抑制

针对硝化反应中2类细菌对环境的敏感程度不同,可由此使硝化反应第2步受到抑制,产生亚硝酸盐的积聚,即短程硝化反应;将引起亚硝酸盐积聚的原因分为2种,相应地将化学物质对生物硝化反应的抑制作用分为2类,将这些可产生选择性抑制作用的化学物质进一步分为无机氮化合物、毒性物质和杀菌类物质.综合分析已有的研究结果,着重讨论了消毒剂作为选择性抑制剂的可行性.从安全性、投加剂量及投加频次等角度分析,认为消毒剂作为选择性抑制剂有很好的应用前景.

固定化活性污泥实现短程硝化反硝化处理畜禽废水

以畜禽废水为处理对象,通过分别控制水力停留时间(HRT)、溶解氧(DO)、pH值、温度和碳氮比(C/N)等影响亚硝化的主要单因子,以使固定化活性污泥颗粒实现短程硝化反硝化反应,在连续流运行模式下进行废水脱氮实验,实验结果表明,单因子HRT为10 h,溶解氧为4 mg/L,pH值为8.5,温度为30℃,碳氮比为10时,对TN和COD的去除率分别为81.98%、93.79%;87.32%、98.35%;83.82%、93.93%;85%、97%;85.37%、97.28%,达到了理想的去除效果。

Advanced removal of organic and nitrogen from ammonium-rich landfil leachate using an anaerobic-aerobic system

A novel system coupling an up-flow anaerobic sludge blanket(UASB) and sequencing batch reactor(SBR) was introduced to achieve advanced removal of organic and nitrogen from ammonium-rich landfill leachate. UASB could remove 88.1% of the influent COD at a volumetric loading rate of 6.8 kg COD·m-3·d-1. Nitritation–denitritation was responsible for removing 99.8% of NH+4-N and 25% of total nitrogen in the SBR under alternating aerobic/anoxic modes. Simultaneous denitritation and methanogenesis in the UASB enhanced COD and TN removal, and replenished alkalinity consumed in nitritation. For the activated sludge of SBR, ammonia oxidizing bacteria were preponderant in nitrifying population, indicated by fluorescence in situ hybridization(FISH) analysis. The Monod equation is appropriate to describe the kinetic behavior of heterotrophic denitrifying bacteria,with its kinetic parameters determined from batch experiments.