氨氮对EGSB反应器处理高浓度有机废水的影响

Effect of ammonia nitrogen on EGSB reactor treatinghigh concentration organic wastewater

在以葡萄糖为基质长期运行的厌氧膨胀颗粒污泥床(EGSB)反应器里,研究了氨氮对EGSB反应器处理高浓度有机废水的影响。结果表明,在进水COD的质量浓度为7000mg/L,有机负荷为48 kg[COD]/(m3.d),水力停留时间为3.5h,回流比为12,水力上升流速为3.38 m/h的条件下,当氨氮的质量浓度小于200mg/L时,对厌氧反应器中的微生物有刺激作用;当氨氮的质量浓度在200～500mg/L时,氨氮浓度的增加对微生物无不利影响,反应器趋于稳定状态,COD去除率为96%左右;当氨氮的质量浓度在500～2000mg/L时,氨氮浓度的变化会对微生物产生短暂的抑制作用,但经过短期的驯化之后即可恢复到原来的状态,此阶段系统运行不稳定;氨氮的质量浓度大于2000mg/L时,则有明显的抑制作用;氨氮的质量浓度达到2736mg/L时,产气量降为47.59L/d,为初始产气量的一半,挥发性有机酸的质量浓度急剧升高至265mg/L,系统出现明显的酸化现象。整个试验过程中,碱度、pH值以及SS随着氨氮浓度的增加稍有增加,但pH值变化不大,基本维持在6.8～7.5。

In an expanded granular sludge bed（EGSB） fed with glucose for long-term operation, the effect of ammonia nitrogen on performance of EGSB reactor treating high concentration organic wastewater was studied. The results showed that, under the condition that the influent COD was 7 000 mg/L, the influent organic loading was 48 kg[ COD ]/（m^3·d）, the hydraulic residence time was 3.5 h, the reflux ratio was 12, and the up flow velocity was 3.38 m/h, when the mass concentration of ammonia nitrogen was less than 200 mg/L, it had a synergistic effect on the microorganism in EGSB reactor. When the mass concentration was 200 - 500 mg/L, the concentration increasing had no disadvantage effect on the microoganism, the reactor operation was stable, the removal rate of COD was about 96%; when the mass concentration was 500 - 2 000 mg/L, the microoganism would be restrained with the concentration variation for a short time, but very soon recover after a short period of domestication, the reactor was not stable at this stage; however, when the mass concentration was above 2 000 mg/L, it had obvious inhibition effect on the microoganism; when the mass concentration reached 2 736 mg/L, the gas production rate reduced to 47.59 L/ d, which was half of the initial gas production rate, the mass concentration of volatile fatty acids（VFA） increased to 265 mg/L rapidly, the system appeared distinct acidification phenomena. Throughout the whole experiment, alkalinity, pH value and SS increased slightly with the increasing of the ammonia nitrogen concentration, but the pH didn＇t change too much, which was maintained at 6.8 - 7.5.