Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
Environ Int. 2019 Oct;131:105020. doi: 10.1016/j.envint.2019.105020. Epub 2019 Jul 18.
Nanoscale zero-valent iron (nZVI), although being increasingly used in anaerobic systems for strengthening the removal of various refractory pollutants, is limited by various inherent drawbacks, such as easy precipitation, passivation, poor mass and electron transfer. To address the above issues, biochar stabilized sulfide-modified nZVI (S-nZVI@BC) was added into an up-flow anaerobic sludge blanket (UASB) to investigate the enhancement of anaerobic biodegradation of nitrobenzene (NB) and its impacts on microbial community structure. The results demonstrated that both NB reduction and aniline formation could be substantially facilitated in S-nZVI@BC coupled system compared to other anaerobic ones coupled with nZVI or S-nZVI. The dosage of S-nZVI@BC resulted in the formation of densely packed aggregates, evidently increased the extracellular polymeric substances content, promoted the volatile fatty acids transformation and stimulated the methane yield. Furthermore, species related to fermentation (Bacteroides and Longilinea), methanogenesis (Methanosarcina and Methanomethylovorans), electroactivity (Pelobacter, Thiobacillus and Phaselicystis) as well as reduction (Desulfovibrio) were considerably enriched in S-nZVI@BC coupled system. The activities of electron transport, total adenosine triphosphate, nitroreductase and NAD(P)H, which were closely related to microbial activity and NB transformation, were increased noticeably in S-nZVI@BC coupled anaerobic system. This study demonstrated the promising potential for long-term operation and full-scale application of S-nZVI@BC coupled system for the treatment of NB containing wastewater.
纳米零价铁（nZVI）虽然在厌氧系统中越来越多地被用于增强各种难降解污染物的去除，但受到各种固有缺陷的限制，如易沉淀、钝化、传质和电子传递不良。为了解决上述问题，将生物炭稳定的硫化物修饰纳米零价铁（S-nZVI@BC）添加到上流式厌氧污泥床（UASB）中，以研究其对硝基苯（NB）厌氧生物降解的强化作用及其对微生物群落结构的影响。结果表明，与其他与 nZVI 或 S-nZVI 耦合的厌氧系统相比，S-nZVI@BC 耦合系统中 NB 的还原和苯胺的形成都可以得到显著促进。S-nZVI@BC 的用量导致紧密堆积的聚集体的形成，明显增加了细胞外聚合物的含量，促进了挥发性脂肪酸的转化，并刺激了甲烷的产率。此外，与发酵（拟杆菌和长螺旋体）、产甲烷（甲烷八叠球菌和甲烷甲基单胞菌）、电活性（Pelobacter、Thiobacillus 和 Phaselicystis）以及还原（脱硫弧菌）相关的物种在 S-nZVI@BC 耦合系统中得到了极大的富集。与微生物活性和 NB 转化密切相关的电子传递、总三磷酸腺苷、硝基还原酶和 NAD（P）H 的活性在 S-nZVI@BC 耦合厌氧系统中明显增加。这项研究表明，S-nZVI@BC 耦合系统在处理含 NB 废水方面具有长期运行和大规模应用的巨大潜力。
