温度变化对短程生物脱氮及N2O释放影响

Effect of Temperature Variation on Short-cut Biological Nitrogen Removal and Nitrous Oxide Release

以生活污水为研究对象,利用序批式活性污泥法反应器(SBR),考察了不同温度下短程生物脱氮过程污染物去除和N2O释放特性。结果表明,利用pH在线控制措施,在pH曲线“氨谷”点及时停止硝化过程,能够在低温下维持稳定的短程硝化过程。不同温度下,系统异养菌COD去除效率无明显差别。随温度降低,NH4^+去除率由95%以上降至21.8%±2.1%,N2O产率由6.37%±0.60%降至0.66%±0.16%。N2O主要产生于硝化过程。中温(≥20℃)和低温(<20℃)下,氨氧化菌(AOB)氧化NH;的温度常数θ分别为1.056和1.140。氨氧化速率(AOR)越大,最高氧化亚氮产生速率(N2OR)出现时间越早。温度升高,AOR增加,提高了N2O-积累速率,促进了以N2O作为终产物的AOB好氧反硝化过程.

With a lab-scale sequencing batch activated sludge reactor(SBR),the effect of temperature on short-cut nitrogen removal process and nitrous oxide release was investigated,and the domestic sewage as the research object.The results showed that the short-cut nitrification was stable at low temperature through pH on-line control measure,stopped the nitrification process at the time when'ammonia valley'appeared on the pH curve.The temperature had no significant effect on COD removal by heterotrophic bacteria.With the decrease of temperature,the NH4*removal rate decreased from more than 95%to 21.8%±2.1%,the N20 yield decreased from 6.37%±0.6%to 0.66%±0.16%.N20 was mainly produced during nitrification process.The temperature coefficient(θ)of ammonia oxidation reaction(AOR)in the reactor was ascertained as 1.056 and 1.140 for ordinary temperatures(≥20℃)and low temperature(<20℃)respectively.The larger the AOR,the earlier the highest N2OR occur.The N02 accumulation increased with the increase of temperature and AOR,and could promote the AOB aerobic denitrification process with N20 as the final product.