游离氨对高浓度含氮废水生物亚硝化的影响

高浓度含氮废水可以建立稳定的生物亚硝化系统,从开始启动到达到稳定亚硝化状态需25d时间,进水NH3-N的质量浓度为800～900mg/L时,出水NH3-N、NO2--N、NO3--N的质量浓度分别为380、335、100mg/L,系统NH3-N的降解率为55%～60%、亚硝化率为80%。启动阶段,系统中亚硝酸菌的生长优势与游离氨的抑制作用并存。随着启动阶段结束及稳定亚硝化系统建立,硝酸菌、亚硝酸菌适应了游离氨的毒害和抑制作用,亚硝酸菌赢得了生长上的优势地位,表现为较高的亚硝化率。NH3-N的氧化活性不受系统生物量影响,以游离氨体积浓度直接衡量其所受的抑制性,而NO2--N的氧化活性与系统生物量有关,以游离氨污泥负荷为基础衡量。维持游离氨污泥负荷小于0.1是取得良好亚硝化效果和氨氮降解率的前提。

The influence of free ammonia on biological nitrous nitrifying of high nitrogen-containing wastewater

High nitrogen-containing wastewater can establish stable biological nitrous nitrifying system, and it takes 25 d from the system startup to the stable operation state of the biological nitrous nitrifying. When the mass concentration of influent NH3-N was 800 - 900 mg / L, the mass concentration of NH3-N, NO2--N, NO3--N were 380, 335, 100 mg / L respectively, the degradation rate of NH3-N and the nitrosation rate of the system were 55% - 60% and 80% respectively. The growth advantage of the nitrosobacteria and the inhibition effect of the free ammonia co- exist in the starting stage of the system. Along with the end of the starting stage and the establishment of the stable nitrous nitrifying system, the nitrate bacteria and nitrosobacteria were adapted to the toxicity and inhibition of the free ammonia, and the nitrosobacteria held a dominant position which reflected the high rate of nitrosation. The oxidation activity of NH3-N was not affected by the biomass of microorganisms and its inhibition effect was directly measured by the volume concentration of free ammonia; however, the oxidative activity of NO2--N was related to the biomass of microorganisms and was measured by the sludge load of free ammonia. It was indicated that, maintaining the sludge load less than 0.1 was the precondition of obtaining good nitrosation effect and degradation rate of NH3-N.