Meta-analysis of bioenergy recovery and anaerobic digestion in integrated systems of anaerobic digestion and microbial electrolysis cell

Abstract

In current study, a meta-analysis approach was used to identify and evaluate the impact of various factors on the performance of integrated systems of anaerobic digestion with microbial electrolysis cell. In this study, related articles on the topic were systematically identified and collected according to the considered criteria, and the effect size that refers to the value of the difference between variables mean (total chemical oxygen demand (TCOD) removal rate and CH4 yield) was estimated. According to the meta-analysis, fed-batch operation mode, the range of 20< temperature <= 30 degrees C, metal cathodes, the range of 500< anode surface area <= 5000 cm(2), HRT (hydraulic retention time) >20 days, 0.6< applied voltage <= 0.8 V, utilization of buffer solution and lack of membrane have high positive impact on the TCOD removal rate. Also, batch operation mode, the range of 30< temperature <= 40 degrees C, metal cathodes with non-Pt catalyst, the range of 100< anode surface area cm(2) <= 500, HRT < 2 days, 0.4< applied voltage <= 0.6 V, utilization of buffer solution and membrane have high positive impact on methane yield. Analysis of the results showed this approach is a scientific and reliable method for identifying and estimating the best range of factors affecting AD-MEC (anaerobic digester combined with MEC) performance.