第一作者:Xiaojing Wen
通讯作者:Yongyou Hu
通讯单位:华南理工大学
文章链接:https://doi.org/10.1016/j.biortech.2023.129073
亮点
提出了一种新型沸石球内循环气升反应器并进行了试验。
SND是主要的生物脱氮机制。
在适宜条件下,ZS-ALR对TN的去除率可达96.12%。
沸石球既可以作为氨氮吸附剂,也可以作为生物膜载体。
吸附和载体作用促进了ZS-ALR的反硝化作用。
摘要
以沸石球为生物膜载体(ZS-ALR)构建了内循环气升反应器,并对其脱氮性能和脱氮机理进行了研究。结果表明,在HRT为6 ~ 8 h、曝气速率为80 ~ 120 mL/min、C/N为4 ~ 6的条件下,ZS-ALR对TN、NH4+-N和TOC的去除率分别达到96.12%、100%和94.54%,最高TN去除率常数为0.01156 min−1(Fig.1-2)。进一步研究氨氮浓度对脱氮和生物膜稳定性的影响,发现分解代谢在脱氮过程中起重要作用(Fig.3),起主要脱氮作用的属包括Sphaerotilus(42.20%)、Flavobacterium(17.47%)和Fusibacter (6.14%)(Fig.5)。氨氮浓度对amoA、napA、narG和nosZ基因丰度有显著影响(Fig.4)。ZS-ALR的脱氮主要通过沸石球吸附氨氮和生物膜同步硝化反硝化进行(Fig.6)。
Fig. 1. The removal performances of nitrogen and TOC in the ZS-ALR under different HRT (a), aeration rates (b), C/N ratios (c) and influent ammonia-N concentrations (d).
Fig. 2. Kinetics of TN removal at different aeration rates (a), C/N ratios (b) and influent ammonia-N concentrations (c).
Fig. 3. Nitrogen balance characteristics in the ZS-ALR at different influent ammonia-N concentrations (a: 25 mg/L; b: 50 mg/L; c: 200 mg/L). The inner ring and the outer ring respectively represent the proportion of various types of nitrogen before and after the reaction.
Fig. 4. EEM fluorescence spectra during ZS-ALR operation at different influent ammonia-N concentrations (a: 25 mg/L; b: 50 mg/L; c: 200 mg/L). The abundance of nitrogen removal genes in the ZS-ALR (d). Different lowercase letters above the bars indicate significant differences in the same gene at different influent ammonia nitrogen concentrations (p <0.05).
Fig. 5. Taxonomic compositions of biofilm at the phylum (a) and class (b) levels; heatmap at genus-level taxa in the ZS-ALR (c).
Fig. 6. Proposed mechanism of nitrogen removal in the ZS-ALR.
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