Regional Environment Conservation Division, National Institute for Environmental Studies (NIES), 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan.
Department of Civil Engineering and Architecture, National Institute for Technology, Tokuyama College, 3538 Gakuendai, Shunan, Yamaguchi 745-8585, Japan.
J Hazard Mater. 2022 Oct 15;440:129764. doi: 10.1016/j.jhazmat.2022.129764. Epub 2022 Aug 12.
Monoethanolamine (MEA), a toxic organic chemical, is widely used in industries and is found in their wastewater. Anaerobic MEA degradation is an appropriate strategy to reduce energy and cost for treatment. Industry wastewaters also contain sulfate, but information on the effects of sulfate on MEA degradation is limited. Here, an up-flow anaerobic sludge blanket (UASB) for MEA-containing wastewater treatment was operated under psychrophilic conditions (18-20 ºC) to investigate the effects of sulfate on the microbial characteristics of the retained sludge. To acclimatize the sludge, the proportion of MEA in the influent (containing sucrose, acetate, and propionate) was increased from 15% to 100% of total COD (1500 mg L); sulfate was then added to the influent. The COD removal efficiency remained above 95% despite the increase in MEA and sulfate. However, granular sludge disintegration was observed when sulfate was increased from 20 to 330 mg L. Batch tests revealed that propionate and acetate were produced as the metabolites of MEA degradation. In response to sulfate acclimation, methane-producing activities for propionate and hydrogen declined, while sulfate-reducing activities for MEA, propionate, and hydrogen increased. Accordingly, acclimation and changes in dominant microbial groups promoted the acetogenic reaction of propionate by sulfate reduction.
单乙醇胺（MEA）是一种有毒的有机化学物质，广泛应用于工业领域，并且存在于其废水中。厌氧 MEA 降解是一种降低处理能耗和成本的合适策略。工业废水还含有硫酸盐，但有关硫酸盐对 MEA 降解影响的信息有限。在这里，采用上流式厌氧污泥床（UASB）在低温（18-20°C）条件下处理含 MEA 的废水，以研究硫酸盐对保留污泥微生物特性的影响。为了使污泥适应，进水（含有蔗糖、乙酸盐和丙酸盐）中 MEA 的比例从 COD（1500mg/L）的 15%增加到 100%；然后向进水中添加硫酸盐。尽管 MEA 和硫酸盐的增加，但 COD 去除效率仍保持在 95%以上。然而，当硫酸盐从 20 增加到 330mg/L 时，观察到颗粒污泥解体。批处理试验表明，丙酸和乙酸盐是 MEA 降解的代谢产物。为了适应硫酸盐，用于丙酸和氢气的产甲烷活性下降，而用于 MEA、丙酸和氢气的硫酸盐还原活性增加。因此，适应和主要微生物群的变化促进了硫酸盐还原的丙酸的产酸反应。
