Microbial fuel cell: An energy harvesting technique for environmental remediation

Abstract

Pollution of soil and water environments is mainly due to different anthropogenic factors, and the presence of organic contaminants, in particular persistent, bioaccumulative and toxic ones, arouses concern for their possible effects on environment and human health. One nature-based technology that can be used in biodegradation of contaminated soil and water is microbial fuel cells (MFCs). They are also capable of producing energy and of being used as environmental sensors. In this context, this article aims at presenting the capacity of MFCs to reduce environmental pollution by exploiting the process of bioelectrochemical utilization of organic matter via microbial metabolism, to generate usable byproducts, fuels and bioelectricity. The main characteristic of an MFC, when used for energy harvesting, is the absence of emissions of pollutant gases such as CO, CO 2 , SOx or NOx. This characteristic, together with the intrinsic capacity of bioreactors to decontaminate soils and water, is stimulating the research into engineering solutions exploiting the MFC potential. Among the different types of MFCs, as bioelectrochemical systems (BESs), the terrestrial microbial fuel cells and the wastewater microbial fuel cells convert energy using a biocatalyst (microorganism) and a biofuel (organic substrate) in basic environments such as soil and water. Consequently, MFCs can be used as energy sources for powering sensors with low-power and low-voltage characteristics or complete single nodes of a distributed wireless sensor network, if coupled with smart although more complex electronic circuit. Moreover, MFCs can be environmental sensors, suited to monitoring some environmental parameters influencing MFC functional behaviours such as pH and temperature. This article introduces the polluted environment scenarios where these technologies could be suitably applied together with the description of two main types of MFC structures and their functioning. Furthermore, some case studies in which MFCs are used in decontamination of polluted environments are described.

Trends and Prospects of Sediment Microbial Fuel Cells as Sustainable Aquatic Ecosystem Remediation Technology

“…245) 이러한 내부 저항을 줄이기 위해서는 전극간의 거리를 줄여 내부 저항의 대부분을 차지하 는 옴 저항(ohm resistance)을 줄이거나, 전극에 추가적인 처리 를 통해 전하 이동 저항(charge transfer resistance)을 줄여야 한다. 246,247) 하지만 전극간의 거리가 너무 가까우면 오히려 성능 이 감소할 수 있다. 26,198,244,248,249) 그리하여 SMFC의 성능을 향 상시키기 위해서 전극간의 최적의 거리에 관한 추가적인 연구 가 필요한 실정이다.…”

Bio-Electrochemical System Depollution Capabilities and Monitoring Applications: Models, Applicability, Advanced Bio-Based Concept for Predicting Pollutant Degradation and Microbial Growth Kinetics via Gene Regulation Modelling

“…In 2020, a case study of MFCs using soil contaminated with DDE (2,2-bis (dichlorodiphenyl-dichloroethylene or p-chlorophenyl)-1,1-dichloroetylene), a persistent metabolite of the DDT (dichlorodiphenyl-trichloroethane) pesticide, was conducted to analyse the cell characteristics and the effectiveness in removing soil contamination by a persistent organic pollutant [30,31]. MFCs have been tested for triggering and promoting DDE degradation by stimulating exo-electrogen microorganisms that catalyse oxidation and reduction reactions in two electrodes.…”

Environmental Remediation and Possible Use of Terrestrial Microbial Fuel Cells

“…Biodegradation can occur in soil, because natural microbial communities (and in particular Bacteria) have a great physiological versatility and catabolic potential, leading to breakdown of an enormous number of organic molecules, including persistent organic pollutants [1]- [3]. Bioremediation includes bioaugmentation (addition of previously selected microorganisms for removing specific contaminants) and biostimulation (addition of nutrients, oxygen, electron donors or acceptors).…”

“…The oxidation of organic contaminants by electroactive bacteria is performed in anaerobic conditions, thanks to a high soil moisture. A soil moisture close to the maximum water holding capacity of soil and a constant environmental temperature favour microbial activity and promote TMFC performance (in terms of electricity production and organic contaminant degradation) [1], [3]. Even if in the case of TMFCs used for organic contaminant biodegradation the electricity outputs can be relatively low, this technology can be effective for bioremediation purposes.…”