Aslan Sukru, Miller Lindsey, Dahab Mohamed
Cumhuriyet University, Department of Environmental Engineering, 58140 Sivas, Turkey.
Bioresour Technol. 2009 Jan;100(2):659-64. doi: 10.1016/j.biortech.2008.07.033. Epub 2008 Aug 30.
In this study, the effects of sludge retention time (SRT) on NH(4)-N oxidation and NO(x)-N accumulation in the nitritation reactors were studied. The gradually decrease of SRT also caused long reaction time to achieve 99% NH(4)-N removal. Although the target NH(4)-N removal was achieved in a short reaction time at 40 days of SRT, decreasing of SRT from 40 to 30, 25, 20 days, increase the reaction time from 168 to 240 and 265 h, respectively. The inlet NH(4)-N was almost oxidized and the concentration of NO(2)-N accumulated to a high level of 177 mg/l, while NO(2)-N/(NO(3)-N+NO(2)-N) ratio was about 0.9 at SRT of 40 days. However, the concentration of NO(3)-N increased slightly and NO(2)-N/(NO(x)-N) ratio dropped to 0.8 when the SRT was lower than 40 days. During the operation in a cycle, free ammonia concentration in the SBR was decreased from 2.8 to 0.7 mg/l which is below the lowest concentration causing inhibition of nitrite oxidizing bacteria (NOB). It was assumed that combined dissolved oxygen limitation and NH(3)-N inhibition on NOB caused NO(2)-N accumulation under the experimental conditions.
本研究考察了污泥停留时间（SRT）对亚硝化反应器中NH(4)-N氧化及NO(x)-N积累的影响。SRT的逐渐降低也导致实现99%的NH(4)-N去除所需的反应时间延长。尽管在SRT为40天时能在较短反应时间内实现目标NH(4)-N去除，但将SRT从40天降至30天、25天、20天，反应时间分别从168小时增加到240小时和265小时。进水NH(4)-N几乎被完全氧化，NO(2)-N浓度积累至177 mg/l的高水平，而在SRT为40天时，NO(2)-N/(NO(3)-N + NO(2)-N)比值约为0.9。然而，当SRT低于40天时，NO(3)-N浓度略有增加，NO(2)-N/(NO(x)-N)比值降至0.8。在一个周期的运行过程中，SBR中的游离氨浓度从2.8 mg/l降至0.7 mg/l，低于抑制亚硝酸盐氧化菌（NOB）的最低浓度。推测在实验条件下，溶解氧限制和NH(3)-N对NOB的抑制共同作用导致了NO(2)-N的积累。
