厌氧铁氨氧化处理模拟垃圾渗滤液的影响因素研究

厌氧条件下,微生物将NH~+_4-N氧化和Fe~(3+)还原的反应称为厌氧铁氨氧化(Feammox).试验以处理垃圾渗滤液的厌氧氨氧化污泥(ANAMMOX)为接种污泥驯化Feammox污泥,研究了不同NH~+_4-N及Fe~(3+)浓度对Feammox系统的影响,并采用扫描电镜(SEM)分析了Feammox系统不同运行阶段的污泥形态特征.结果表明:在厌氧序批式反应器中,在常温条件下控制进水NH~+_4-N浓度为50 mg·L~(-1)、pH在7.4～7.6之间,经过88 d厌氧富集培养后NH~+_4-N最大转化率达到52.73%,最大转化量为28.37 mg·L~(-1),出水Fe~(2+)浓度随着运行时间的增加逐渐增加,最高浓度为2.87 mg·L~(-1).高浓度NH~+_4-N(400 mg·L~(-1))和Fe~(3+)(500 mg·L~(-1))条件下,氨氮转化量分别达到了40.69 mg·L~(-1)和29.23 mg·L~(-1),说明高进水基质条件下仍然有Feammox反应发生.低浓度NH~+_4-N(100 mg·L~(-1))和Fe~(3+)(50 mg·L~(-1))条件下,NH~+_4-N转化量与Fe~(2+)生成量的线性关系较强,R~2分别为0.86544和0.86034.通过SEM分析可得,Feammox污泥表面附着有不规则矿物,这些矿物沉积在微生物细胞表面阻碍传质,从而降低微生物代谢效率.

Study on the factors affecting simulated landfill leachate treatment by anaerobic ferric ammonia oxidation

Under anaerobic conditions, the simultaneous NH₄⁺-N oxidation and Fe³⁺ reduction induced by anaerobic microorganisms have been described as anaerobic ferric ammoxidation (Feammox). The anaerobic ammonium oxidation (ANAMMOX) sludge for treating landfill leachate was adopted as seed sludge to cultivate Feammox sludge in this study. Effects of different NH₄⁺-N and Fe³⁺ concentrations on the Feammox system were investigated and the morphological characteristics of the sludge in Feammmox system at different operating stages were analyzed with scanning electron microscopy (SEM). The results showed that when the influent concentration of NH₄⁺-N was 50 mg·L^-1 and pH between 7.4 to 7.6 in the anaerobic sequential batch reactor under normal temperature, the maximum conversion and its ratio of NH₄⁺-N reached 28.37 mg·L^-1 and 52.73% respectively,after 88 days of anaerobic enrichment, while the effluent Fe²⁺ concentration increased with the running time and the highest concentration was 2.87 mg·L^-1. Under the conditions of high concentration of NH₄⁺-N (400 mg·L^-1) and Fe³⁺ (500 mg·L^-1), the ammonia-nitrogen conversion reached 40.69 mg·L^-1 and 29.23 mg·L^-1, respectively, indicating that the Feammmox reaction still occurred under high substrate concentration. Under the conditions of low concentration of NH₄⁺-N (100 mg·L^-1) and Fe³⁺ (50 mg·L^-1), the NH₄⁺-N conversion correlated well with the Fe²⁺ productionwith R² of 0.86544 and 0.86034, respectively. According to SEM analysis, the irregular Fe minerals were attached to the surface of Feammox sludge, which inhibited the mass transfer and reduced the efficiency of microbial metabolism.