Zhen Guangyin, Lu Xueqin, Kobayashi Takuro, Su Lianghu, Kumar Gopalakrishnan, Bakonyi Péter, He Yan, Sivagurunathan Periyasamy, Nemestóthy Nándor, Xu Kaiqin, Zhao Youcai
Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration, School of Ecological and Environmental Sciences, East China Normal University, Dongchuan Rd. 500, Shanghai, 200241, PR China; Center for Material Cycles and Waste Management Research, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki, 305-8506, Japan.
Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 980-8579, Japan.
Chemosphere. 2017 Aug;180:229-238. doi: 10.1016/j.chemosphere.2017.04.006. Epub 2017 Apr 5.
The dispersion of granules in upflow anaerobic sludge blanket (UASB) reactor represents a critical technical issue in methanolic wastewater treatment. In this study, the potentials of coupling a microbial electrolysis cell (MEC) into an UASB reactor for improving methanolic wastewater biodegradation, long-term process stability and biomethane recovery were evaluated. The results indicated that coupling a MEC system was capable of improving the overall performance of UASB reactor for methanolic wastewater treatment. The combined system maintained the comparatively higher methane yield and COD removal efficiency over the single UASB process through the entire process, with the methane production at the steady-state conditions approaching 1504.7 ± 92.2 mL-CH L-reactor d, around 10.1% higher than the control UASB (i.e. 1366.4 ± 71.0 mL-CH L-reactor d). The further characterizations verified that the input of external power source could stimulate the metabolic activity of microbes and reinforced the EPS secretion. The produced EPS interacted with Fe liberated during anodic corrosion of iron electrode to create a gel-like three-dimensional [-Fe-EPS-] matrix, which promoted cell-cell cohesion and maintained the structural integrity of granules. Further observations via SEM and FISH analysis demonstrated that the use of bioelectrochemical stimulation promoted the growth and proliferation of microorganisms, which diversified the degradation routes of methanol, convert the wasted CO into methane and accordingly increased the process stability and methane productivity.
颗粒在升流式厌氧污泥床（UASB）反应器中的分散是甲醇废水处理中的一个关键技术问题。在本研究中，评估了将微生物电解池（MEC）与UASB反应器耦合以提高甲醇废水生物降解、长期工艺稳定性和生物甲烷回收的潜力。结果表明，耦合MEC系统能够提高UASB反应器处理甲醇废水的整体性能。在整个过程中，联合系统比单一UASB工艺保持了相对较高的甲烷产量和COD去除效率，稳态条件下的甲烷产量接近1504.7±92.2 mL-CH₄ L-反应器⁻¹ d，比对照UASB（即1366.4±71.0 mL-CH₄ L-反应器⁻¹ d）高约10.1%。进一步的表征证实，外部电源的输入可以刺激微生物的代谢活性并增强EPS的分泌。产生的EPS与铁电极阳极腐蚀过程中释放的铁相互作用，形成凝胶状三维[-Fe-EPS-]基质，促进细胞间凝聚并维持颗粒的结构完整性。通过SEM和FISH分析的进一步观察表明，生物电化学刺激的使用促进了微生物的生长和增殖，使甲醇的降解途径多样化，将浪费的CO转化为甲烷，从而提高了工艺稳定性和甲烷生产率。
