接种污泥类型对厌氧铁氨氧化反应启动影响与微生物解析

Effect of inoculation sludge type on the start-up of Fe(Ⅲ)reduction coupled to anaerobic ammonium oxidation(Feammox)process and the microbial analysis

以厌氧消化污泥、厌氧氨氧化污泥为接种污泥,探讨不同接种污泥对厌氧铁氨氧化反应(Feammox)启动及铁氮比对氨氮去除的影响.结果表明,厌氧消化污泥组的启动更快,在第17 d时显现脱氮效果,第17~39 d的氨氮平均去除率为20.03%,经过86 d的Feammox反应后最高氨氮去除率为60.51%;而厌氧氨氧化污泥组的氨氮去除率最高为52.67%.采用修正的Gompertz模型对两个试验组的氨氮去除进行拟合,结果表明,厌氧消化污泥组的平均迟滞期为17.21 d,脱氮速率为1.66 g·m^(-3)·d^(-1);厌氧氨氧化污泥组的平均迟滞期为33.08 d,脱氮速率为0.94 g·m^(-3)·d^(-1).X射线衍射(XRD)分析表明,水铁矿(以三氧化二铁为主)在厌氧消化污泥组经86 d试验后转化为碳酸亚铁(菱铁矿),在厌氧氨氧化污泥组主要转化为碳酸亚铁(菱铁矿)和四氧化三铁(磁铁矿).微生物群落分析结果表明,厌氧消化污泥组的微生物多样性、丰富度较高,Chloroflexi、Proteobacteria、Bacteroidota和Planctomycetota出现了富集.通过PICRUSt2基因预测,厌氧消化污泥组经86 d试验后,参与铁结合、运输功能的基因和参与氮代谢的基因大量富集有利于Feammox反应发生,而厌氧氨氧化污泥组中相关功能基因富集较低.

This study investigated the startup of the Fe(Ⅲ)reduction coupled to anaerobic ammonium oxidation(Feammox)process Using anaerobic digestion sludge(ADS)and anaerobic ammonia oxidation(Anammox)sludge as inoculum.It also exmined the effect of iron-nitrogen ratio on ammonia nitrogen removal.The results showed that the treatment with ADS had a faster startup and achieved stable denitrification on day 17,the average ammonia removal rate reached 20.03%at day 17~39 and 60.51%after 86 days of Feammox reaction,while the treatment with Anammox sludge had a maximum ammonia removal rate of 52.67%.simulated with the modified Gompertz model for ammonia removal,the results showed that the lag period was singificantly shorter with ADS inoculation(17.21 days)compared to Anammox inoculation(33.08 days).the respective ammonia removal rate was 1.66 g·m^(-3)·d^(-1) in the AD and 0.94 g·m^(-3)·d^(-1) in the anammox inoculation experiment.X-ray diffraction analysis showed that the prepared ferrihydrite(mainly ferric oxide)was converted to ferrous carbonate(rhodochrosite)in AD inoculation experiment after 86 d.In contrast,the anammox inoculation mainly resulted in ferrous carbonate(rhodochrosite)and ferric oxide(magnetite).The microbial community analysis showed that the AD inoculation obtained higher diversity and richness,and the phyla of Chloroflexi,Proteobacteria,Bacteroidota and Planctomycetota were enriched.gene prediction with PICRUSt2 analysis showed that the genes encoding iron transport and binding protein and the genes related to nitrogen metabolism were highly enriched,which promoted the feammox process.But the above genes in anammox inoculation experiment were relatively low.