回流比对短程硝化-厌氧氨氧化组合工艺处理晚期垃圾渗滤液自养脱氮的影响

采用"连续流短程硝化-厌氧氨氧化组合工艺"处理低碳氮比高氨氮浓度的晚期垃圾渗滤液.主要考察了在不同外回流比(100%~600%)的条件下,A/O反应器中氨氮转化率以及亚硝酸盐积累率的变化,游离氨(free ammonia,FA)与游离亚硝酸(free nitrite acid,FNA)的平均质量浓度变化;UASB反应器的厌氧氨氧化活性及其在相同高度(10 cm)处的粒径变化情况.试验结果表明,当回流比维持在300%时,A/O反应器中的亚硝酸盐氧化细菌(nitrite oxidizing bacteria,NOB)被FA和FNA联合抑制,进而达到了较好的短程硝化效果,A/O反应器中氨氮转化率、亚硝酸盐积累率分别达到93.5%、95.6%以上,UASB厌氧氨氧化反应器污泥持留性与活性均达到较高的水平,总氮去除负荷达到1.04 kg/(m~3·d)以上.定量PCR结果表明,厌氧氨氧化菌占全菌的比例达到了试验期间的最大值3.78%.

Effect of Recycling Ratio on the Combined Process of Nitritation-ANAMMOX for the Autotrophic Nitrogen Removal of Mature Landfill Leachate

A combined continuous-flow process of A/OSHORTCUT-UASBANAMMOX was applied to treat mature leachate which contained high concentration of ammonia and low COD/nitrogen rate. The conversion rate of ammonia,nitrite accumulation ratio and the variation of FA and FNA concentrations in A/O reactor, the nitrogen removal activity of ANAMMOX and the variation of granules sizes at the same height ( 10 cm) were investigated at different recycling ratios (100%-600%) . The results indicated that when the recycling ratio came to 300%, with the help of associated inhibition of FA and FNA to NOB, the conversion rate of ammonia and nitrite accumulation ratio in A/O reactor were kept above 93. 5% and 95. 6%,respectively. In addition, the ANAMMOX granules were well retained in the UASB reactor and kept a high level of total nitrogen removal rate. The nitrogen removal rate of UASB reactor kept above 1. 04 kg/(m3·d). Also, the results of quantitative PCR(polymerase chain reaction) indicated that the proportions ofANAMMOXin UASB reactor were 3. 78% which was the maximum value of the whole experiment.