电解电压对电化学厌氧消化的影响

Influence of Applied Voltage on Electrochemical Anaerobic Digestion

该文采用批量发酵实验,以厌氧活性污泥为接种物,乙酸为碳源,研究了不同电解电压对电化学厌氧消化(EAD)产甲烷性能的影响。结果表明,在电解电压为1.0 V时,CH_(4)含量可达85.3%,相比对照组提高了14.4%,而CO_(2)含量可低至10%,相比对照组降低了7%。与对照组相比,实验组(0.2~1.6 V)的理论甲烷转化率和比产甲烷速率均有不同程度的提高,且在0.4~1.4 V电压区间的提高程度较大。通过电化学特性和微生物分析发现,当电解电压超过0.4 V时,EAD回路中才会有电流形成,这可能是EAD阳极表面电活性微生物附着生长且与电极进行电子传递的结果。此外,EAD阳极膜生物量越高,其电化学活性也越强,回路中的电流也就越大,相应的产甲烷转化率和比产甲烷速率也越高。

This paper elaborated on a bench-scaled experiment, involving a batch fermentation technology, which was used to study the effect of varied applied voltages on the methane production performance of the electro-chemical anaerobic digestion(EAD) by means of anaerobic activated sludge as the inoculum and acetic acid as the carbon source. The findings of the experiment indicated that when applied voltage was 1.0 V, CH;content could rise up to 85.3%, up 14.4% compared with the control group, while the CO;content dropped down to 10%, a decrease of 7%, compared with the control group. In contrast with the control group, both of EAD theoretical methane conversion rate and specific methane production rate were improved in different degrees, particularly in the voltage range from 0.4 V to 1.4 V. Through the analyses with respect to electro-chemistry and microbiology, it was found that only as applied voltage exceeded 0.4 V, EAD circuit could generate current, probably owing to the attachment and growth of electroactive microorganisms on EAD anode surface, and the electron transfer with the electrode.In addition, the higher the biomass of EAD anode film was, the stronger its electrochemical activity, and the greater the current in the loop was, the higher the corresponding methane conversion rate and the specific methane production rate would be.