In order to achieve fuzzy control of nitrification in a Sequencing Batch Reactor (SBR) brewery wastewater was used as the substrate. The effect of alkalinity on pH variation during nitrification was systematically studied, at the same time the variations of DO and ORP were investigated. Alkalinity and pH of the wastewater were adjusted by adding sodium bicarbonate at five levels and sodium hydroxide at two levels. Unadjusted wastewater was also studied. According to the results, variation of pH could be divided into rising type and descending type. When bicarbonate alkalinity was deficient or sufficient, the descending type happened. If alkalinity was deficient, the pH decreasing rate got slower when nitrification nearly stopped; if alkalinity was sufficient, at the end of nitrification pH turned from decrease to increase. This was the most common situation and pH could be used to control the end of nitrification. When alkalinity was excessive, the rising type happened, pH was increasing at nearly a constant rate during and after nitrification and could not be used to control the nitrification time, but if the aeration rate was moderate DO could be used to control the nitrification time. This situation seldom happened. Therefore the variation of pH could not only be used to control the nitrification time but also to judge whether the alkalinity was enough or not. On the basis of this, the fuzzy controller of nitrification in SBR was constructed. When discussing the influence of pH on nitrification rate the composition and concentration of alkalinity must be considered or else the results may be incomprehensive. And to some extent the influence of alkalinity on nitrification rate was more important than pH.

A novel control strategy for biological nitrogen removal with high nitrite built-up through chlorine dosage was studied. In the biological nitrogen removal process operated in a bench-scale sequencing batch reactor, dose of chlorine of 0.2 mg/l in the form of sodium hypochlorite was applied after the COD was depleted. The aerobic phase switched to an anoxic phase shortly after the ammonium was completely biotically oxidized. Nitrite accumulation was stably achieved which was attributed to the chlorination and the lag-time of nitrification. With the time control, stable 100% conversion of nitrite could also be sustained even under the absence of chlorine for at least 20 days. The nitrite oxidizer should have been killed rather than been suppressed in this study. For engineering applications, the advantages of the nitrification/denitrification via nitrite can compensate the cost of chlorine dosage. Combined with the aeration time control, it is feasible to apply chlorination in a biological nitrogen removal process in SBRs.

以生活污水为处理对象，对基于缺氧吸磷理论开发出的连续流厌氧/缺氧-硝化（A2N）双污泥新工艺反硝化除磷脱氮的性能进行了考察。试验结果表明：A2N双泥系统能使硝化菌和反硝化聚磷菌分别在各自最佳的环境中生长，利于系统脱氮除磷的稳定和高效，可控制性也得到了提高。研究发现，当进水ρ（C）/ρ（N）为3.97时，ρ（总氧，TN）/ρ（总磷，TP）和化学耗氧量（COD）去除率分别为80.99%，92.87%和91%；而当提高进水ρ（C）/ρ（N）至6.49时，可进一步提高脱氮除磷效果，ρ（TN），ρ（TP）和COD去除率分别达到92.7%，97.95%和95%。可见，该工艺较适合进水COD/ρ（TN）偏低的城市污水脱氮除磷处理。

In this study, laboratory-scale experiments were conducted applying a Sequencing Batch Reactor (SBR) activated sludge process to a wastewater stream from a pharmaceutical factory. Nitrogen removal can be achieved via partial nitrification and denitrification and the efficiency was above 99% at 23

Dissolved oxygen (DO) concentration profiles were characterized during the aerobic organic substrate removal phase in a sequencing batch reactor (SBR) for the treatment of a chemical industrial wastewater. In the initial stage (0