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

摘要

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/(m3·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%.%A combined continuous-flow process of A/OSHORTCUT-UASBANAMMOX was applied to treat mature leachate which contained high concentration of ammonia and low CODitrogen 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.