Teng Wen-Kai, Liu Guang-Li, Luo Hai-Ping, Zhang Ren-Duo, Fu Shi-Yu
Huan Jing Ke Xue. 2015 Mar;36(3):1021-6.
The chemical oxygen demand (COD) of substrate can affect the microbial activity of both anode and cathode biofilm in the single-chamber methanogenic microbial electrolysis cell (MEC). In order to investigate the effect of COD on the performance of MEC, a single chamber MEC was constructed with biocathode. With the change of initial concentration of COD (700, 1 000 and 1 350 mg x L(-1)), the methane production rate, COD removal and energy efficiency in the MEC were examined under different applied voltages. The results showed that the methane production rate and COD removal increased with the increasing COD. With the applied voltage changing from 0.3 to 0.7 V, the methane production rate increased at the COD of 700 mg x L(-1), while it increased at first and then decreased at the COD of 1000 mg x L(-1) and 1350 mg x L(-1). A similar trend was observed for the COD removal. The cathode potential reached the minimum (- 0.694 ± 0.001) V as the applied voltage was 0.5 V, which therefore facilitated the growth of methanogenic bacteria and improved the methane production rate and energy efficiency of the MEC. The maximum energy income was 0.44 kJ ± 0.09 kJ (1450 kJ x m(-3)) in the MEC, which was obtained at the initial COD of 1000 mg x L(-1) and the applied voltage of 0.5 V. Methanogenic MECs could be used for the treatment of wastewaters containing low organic concentrations to achieve positive energy production, which might provide a new method to recover energy from low-strength domestic wastewater.
底物的化学需氧量（COD）会影响单室产甲烷微生物电解池（MEC）中阳极和阴极生物膜的微生物活性。为了研究COD对MEC性能的影响，构建了一个带有生物阴极的单室MEC。随着初始COD浓度（700、1000和1350 mg·L⁻¹）的变化，在不同外加电压下考察了MEC中的甲烷产率、COD去除率和能量效率。结果表明，甲烷产率和COD去除率随COD的增加而提高。当外加电压从0.3 V变为0.7 V时，在COD为700 mg·L⁻¹时甲烷产率增加，而在COD为1000 mg·L⁻¹和1350 mg·L⁻¹时，甲烷产率先增加后降低。COD去除率也观察到类似趋势。当外加电压为0.5 V时，阴极电位达到最小值（-0.694±0.001）V，因此促进了产甲烷菌的生长，提高了MEC的甲烷产率和能量效率。MEC中的最大能量收益为0.44 kJ±0.09 kJ（1450 kJ·m⁻³），这是在初始COD为1000 mg·L⁻¹和外加电压为0.5 V时获得的。产甲烷MEC可用于处理低有机浓度的废水以实现正能量生产，这可能为从低强度生活废水中回收能量提供一种新方法。
