Sulfidogenesis process to strengthen re-granulation for biodegradation of methanolic wastewater and microorganisms evolution in an UASB reactor
Sulfidogenesis process to strengthen re-granulation for biodegradation of methanolic wastewater and microorganisms evolution in an UASB reactor
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DOI：
10.1016/j.watres.2016.10.073
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发表时间：
2017-01-01
期刊：
影响因子：
12.8
通讯作者：
Li, Yu-You
中科院分区：
文献类型：
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作者：
Lu, Xueqin;Zhen, Guangyin;Li, Yu-You
实验室规模的甲醇废水进料 (3000 mg COD L-1) UASB 反应器运行了 235 天，以评估硫化过程对代谢途径、分散颗粒的再造粒和长期工艺性能的影响。通过在 12 g COD L-1 d(-1) 的固定有机负荷率 (OLR) 下逐步将进水 COD/SO42- 比率从 20 降低至 0.5，创建了各种硫化物生成情景。结果表明，甲醇转化为甲烷的转化率在>= 2的宽COD/SO42-范围内稳定，实现了3.78 +/- 0.32 L L-1 d(-1)的高沼气生产率，同时有效去除了总COD (96.5 +/- 4.4%)和硫酸盐(56.3 +/- 13.0%)。对于所有测试的 COD/SO42- 比率，沼气中的甲烷含量保持相对稳定在 81.5 +/- 1.6%。随着 COD/SO42- 比率的降低，颗粒的粒径明显增加。随着 COD/SO42- 比率的降低，产甲烷古菌 (MPA) 使用的电子数量略有线性下降（从 98.5 +/- 0.5% 到 80.0 +/- 2.4%），而硫酸盐还原菌 (SRB) 的消耗则增加（从 1.5 +/- 0.5% 到 20.0 +/- 2.4%）。根据活性测试和微生物群落分析的结果，在低COD/SO42-比率下将甲醇转化为甲烷（除Methanomethylovorans sp.外）不仅取决于低水平的乙酸分解菌和氢营养产甲烷菌，还取决于利用H-2-CO2与乙酸盐矿化甲醇的不完全氧化剂SRB物种（例如Desulfovibrio sp.）。这有助于使甲醇的代谢途径多样化。通过扫描电子显微镜 (SEM) 的进一步分析表明，较低的 COD/SO42- 比率有利于硫化过程并使反应器内的微生物群落多样化。有益的硫化过程随后引发了足够的、刚性的[-Fe-EPS-](n)网络（EPS：胞外聚合物）的形成，结合并固定污泥，并导致分散颗粒的再造粒。 (C) 2016 Elsevier Ltd. 保留所有权利。
A lab-scale methanolic wastewater-fed (3000 mg COD L-1) UASB reactor was operated for 235 days to evaluate the influence of the sulfidogenesis process on metabolic routes, the re-granulation of dispersed granules and long-term process performance. Various sulfidogenesis scenarios were created by stepwise decreasing the influent COD/SO42- ratio from 20 to 0.5 at a fixed organic loading rate (OLR) of 12 g COD L-1 d(-1). It was shown that the conversion of methanol to methane was stable at a wide COD/SO42- range of >= 2, attaining high biogas production rate of 3.78 +/- 0.32 L L-1 d(-1) with efficient concurrent removal of the total COD (96.5 +/- 4.4%) and sulfate (56.3 +/- 13.0%). The methane content in biogas remained relatively stable at 81.5 +/- 1.6% for all COD/SO42- ratios tested. The particle size of the granules was shown to clearly increase as the COD/SO42- ratios decreased. A slight linear decline was noted in the number of electrons utilized by methane producing archaea (MPA) (from 98.5 +/- 0.5% to 80.0 +/- 2.4%), whereas consumption by sulfate reducing bacteria (SRB) increased (from 1.5 +/- 0.5% to 20.0 +/- 2.4%) with the decreasing COD/SO42- ratio. According to the results of activity tests and microbial community analysis, the conversion of methanol to methane at a low COD/SO42- ratio, except from Methanomethylovorans sp., depends not only on low levels of acetoclastic and hydrogenotrophic methanogens, but also on incomplete oxidizer SRB species (e.g. Desulfovibrio sp.) that utilize H-2-CO2 with acetate to mineralize the methanol. This serves to diversify the metabolic pathway of methanol. Further analysis through scanning electron microscopy (SEM) revealed that a lower COD/SO42- ratio favored the sulfidogenesis process and diversified the microbial community inside the reactor. The benefical sulfidogenesis process subsequently invoked the formation of a sufficient, rigid [-Fe-EPS-](n) network (EPS: extracellular polymeric substances), binding and immobilizing the sludge, and resulting in the re-granulation of the dispersed granules. (C) 2016 Elsevier Ltd. All rights reserved.