首页|不同氮负荷下生物炭强化厌氧氨氧化体系脱氮效能的影响

不同氮负荷下生物炭强化厌氧氨氧化体系脱氮效能的影响

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为了探明生物炭对厌氧氨氧化脱氮效能的影响,通过批次实验考察了 3种氮负荷条件下(总氮100、300、500 mg·L-1)厌氧氨氧化体系的总氮去除效果,并从反应前后生物炭性能变化、细菌胞外聚合物分泌水平以及微生物群落演替特征等方面解析了潜在作用机制.结果表明总氮100、总氮300、总氮500组生物炭的添加使体系总氮去除率较对照组分别提升了 13.6%、4.5%、1.8%,且最终硝氮浓度明显低于对照组.这是由于生物炭作为电子介导体,通过其具有的电活性以及氧化还原性能与细菌胞外聚合物相互作用,强化了胞外电子传递过程从而促进了硝氮的还原,且总氮100组效果最佳.通过胞外聚合物分析得出,总氮100生物炭组具有最高平均胞外聚合物分泌浓度,而其浓度随着氮负荷的提高而减小,这源于高氮负荷反应体系具有更高的硝氮累积量,因此EPS作为唯一内源电子供体,在参与硝氮还原的过程中消耗量逐渐增大.高通量测序以及KEGG预测分析表明生物炭在低氮负荷条件下对厌氧氨氧化菌Candidatus Kuenenia以及Acinetobacter、Afipia等反硝化菌相对丰度的提升效果更显著,同时在总氮100生物炭组中由EC:1.7.5.1、EC:1.9.6.1构成的硝酸盐还原酶的相关功能基因具有更高的表达水平,揭示了低氮负荷下生物炭强化氮去除效果更显著的原因.
Effects of nitrogen load on nitrogen removal efficiency of biochar-enhanced anammox systems
To investigate the effects of biochar on the nitrogen removal efficiency of Anammox,batch experiments were conducted.The total nitrogen removal efficiency of the anammox system under three different nitrogen loads(100,300,and 500 mg/L total nitrogen)was examined.The underlying mechanisms were analyzed based on changes in biochar performance before and after reaction,bacterial extracellular polymeric substances secretion levels,and microbial community succession characteristics.Results showed that biochar addition increased the total nitrogen removal efficiency in all groups(TN100,TN300,and TN500)by 13.6%,4.5%and 1.8%,respectively compared with the control group.Additionally,the final nitrate concentration was significantly lower in biochar-amended groups than in the control group.This improvement could be attributed to biochar's electron conductivity and redox properties,which interacted with EPS,promoting extracellular electron transfer and enhancing nitrate reduction,with the most significant effect observed under low nitrogen loads.Analysis of extracellular polymeric substances showed that the TN 100 group with biochar had the highest average extracellular polymeric substances secretion concentration and better sludge structure stability.However,extracellular polymeric substances(EPS)concentration decreased with increasing nitrogen load.This was explained by the higher nitrate accumulation in high nitrogen-loaded anammox systems,leading to increased EPS consumption as an endogenous electron donor during nitrate reduction.High-throughput sequencing and KEGG prediction analysis showed that biochar significantly increased the relative abundance of anammox bacteria Candidatus Kuenenia,as well as the denitrifying bacteria Acinetobacter and Afipia under low nitrogen load conditions.Furthermore,the functional genes for nitrate reductase EC:1.7.5.1 and EC:1.9.6.1 exhibited higher expression levels in the TN 100 group with biochar,revealing the reason for the more significant nitrogen removal efficiency enhanced by biochar under low nitrogen loading conditions.

nitrogen concentrationbiocharanammoxpartial denitrificationmicrobial consortia

周鹏宇、付静薇、贺逸飞、李倩、陈荣、李玉友

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西安建筑科技大学环境与市政工程学院,西安 710055

东北大学工程研究生院土木与环境工程系,日本仙台 980-8579

氮负荷 生物炭 厌氧氨氧化 部分反硝化 微生物群落

2024

环境工程学报
中国科学院生态环境研究中心

环境工程学报

CSTPCD北大核心
影响因子:0.804
ISSN:1673-9108
年,卷(期):2024.18(11)