Treatment of recalcitrant wastewater and hydrogen production via microbial electrolysis cells

Abstract

A large amount of real complex wastewaters are generated every year, which leads to a great environmental burden. Various treatment technologies were deployed to remove the contaminants in the wastewaters. However, these actual wastewaters have not been sufficiently treated due to their complex properties, high-concentration organics, incomplete utilization of hard-biodegradable substrates, the high energy input required, etc. Recently, microbial electrolysis cells (MECs), a great potential technology, has emerged for various wastewater treatment, because not only do they demonstrate satisfactory performance during wastewater treatment, but they also generate renewable H 2 as a clean energy carrier. Unlike previous reviews, this review introduced the characteristics of every complicated wastewater, and focused on analyzing and summarizing MEC development for wastewater treatment. The performances of MECs were systematically reviewed in terms of organics removal, H 2 production, Columbic efficiency, and energy efficiency. MEC performances for treating actual complex wastewaters and producing H 2 can be optimized through operation parameters, electrode materials, catalyst materials, etc. In addition, the challenges and opportunities including complexity of wastewaters, instability of H 2 production, robust microorganisms, effect of membrane on two-chamber MEC, and integration of MEC with other treatment processes were deeply discussed. Except for the technical feasibility, both environmental feasibility and economic feasibility also need to meet social requirements. This review can indeed provide a basis for high-efficiency treatment and practical commercial applications of recalcitrant wastewaters via MECs in the future.

Bioelectrochemical Processes in Industrial Biotechnology

“…There is a further development of the concept of microbial fuel cells. The aim is to treat wastewater by electrolysis facilitated by microbial process in the anodic space of electrolyzer with simultaneous production of hydrogen on the cathode [67][68][69][70][71].…”

Maximizing Bio-Hydrogen Production from an Innovative Microbial Electrolysis Cell Using Artificial Intelligence

“…Additionally, the hydrogen recovery from MECs is much higher than dark fermentation (20%) [27]. Different wastewater could be used as substrates in applying MECs, such as industrial wastewater, domestic wastewater, and food processing wastewater [28][29][30][31]. A dual tubular chamber MEC was fed with domestic wastewater using 0.9 V (applied voltage), achieving a high coulombic efficiency of 98.5% with a hydrogen production rate of 0.18 ± 0.03 m 3 /m 3 .d and 151.9% energy recovery [32].…”

Effectiveness of the pretreatment methods on mesophilic anaerobic co-digestion of fruit, food and vegetable waste

“…Biological or biochemical waste stabilization techniques such as anaerobic codigestion along with some other got potential research attention in the last decade in many developing countries due to it is advantages such as energy and resources recovery (value-added products, chemicals etc.) along with waste reduction (Ariunbaatar et al 2014a;Rodriguez Correa and Kruse 2018;Akshaya and Jacob 2018;Morales-Polo et al 2019;Shen et al 2019;N et al 2020). Anaerobic co-digestion (AD) converts FFVW materials into biogas/biomethane along with quite stabilized organic fertilizer and concurrently treats the residues with reduction in the waste (Akshaya and Jacob 2018;Bayrakdar 2019;Li et al 2019;Chaurasia et al 2020a).…”