Department of Environmental Engineering, Chungbuk National University, Cheongju, 361-763, Republic of Korea.
Chemosphere. 2019 Apr;220:403-411. doi: 10.1016/j.chemosphere.2018.12.169. Epub 2018 Dec 24.
In this study, the effects of indirect voltage supply to an anaerobic digestion (AD) reactor on methane production and the removal of chemical oxygen demand (COD) were studied at different organic loading rates (OLRs) of food waste by the circulation from an auxiliary bio-electrochemical reactor (ABER) with stainless steel (STS304) electrodes. The effects of the indirect voltage on microbial communities in the AD reactor were also investigated. In a bio-electrochemical anaerobic digestion (BEAD) reactor with direct voltage, it was possible to achieve stable COD removal and methane production even at a higher OLR of 10.0 kg/(m·d). However, in the AD reactor, the COD removal efficiency and methane production decreased sharply at an OLR of 6.0 kg/(m·d) due to the accumulation of volatile fatty acids (VFAs) and decreases in the pH and alkalinity. The supply of indirect voltage through the ABER increased the community of exoelectrogenic bacteria and hydrogenotrophic methanogens in the AD + ABER bulk solution. As a result, rapid oxidation of the accumulated VFAs occurred, and methane production increased in the new AD + ABER system. The results confirm that an indirect voltage supply to the new AD + ABER system can have effects similar to those of a direct voltage supply to the BEAD reactor, and the findings are expected to provide useful information for the development and application of BEAD technology for commercialization.
在这项研究中，通过循环从带有不锈钢（STS304）电极的辅助生物电化学反应器（ABER）向厌氧消化（AD）反应器提供间接电压，研究了不同食物废物有机负荷率（OLR）下间接电压对甲烷产生和化学需氧量（COD）去除的影响。还研究了间接电压对 AD 反应器中微生物群落的影响。在带有直流电压的生物电化学厌氧消化（BEAD）反应器中，即使在更高的 OLR 为 10.0 kg/（m·d）下，也可以实现稳定的 COD 去除和甲烷产生。然而，在 AD 反应器中，由于挥发性脂肪酸（VFAs）的积累、pH 值和碱度的降低，在 OLR 为 6.0 kg/（m·d）时，COD 去除效率和甲烷产生急剧下降。通过 ABER 供应间接电压增加了 AD+ABER 主体溶液中放电子细菌和氢营养型产甲烷菌的群落。结果，积累的 VFAs 迅速氧化，新的 AD+ABER 系统中的甲烷产量增加。结果证实，向新的 AD+ABER 系统供应间接电压可以产生类似于向 BEAD 反应器供应直流电压的效果，研究结果有望为 BEAD 技术的开发和应用提供有价值的信息，以实现商业化。
