Constructed wetland integrated microbial fuel cell system: looking back, moving forward

Abstract

In the last 10 years, the microbial fuel cell (MFC) has been extensively studied worldwide to extract energy from wastewater via electricity generation. More recently, a merged technique of embedding MFC into a constructed wetland (CW) has been developed and appears to be increasingly investigated. The driving force to integrate these two technologies lies in the fact that CWs naturally possess a redox gradient (depending on flow direction and wetland depth), which is required by MFCs as anaerobic anode and aerobic cathode chambers. No doubt, the integration of MFC with a CW will upgrade the CW to allow it to be used for wastewater treatment and, simultaneously, electricity generation, making CWs more sustainable and environmentally friendly. Currently, published work shows that India, China, Ireland, Spain, Germany and Malaysia are involved in the development of this technology although it is in its infant stage and many technical issues are faced on system configuration, operation and maximisation of electricity production. This paper aims to provide an updated review and analysis of the CW-MFC development. Focuses are placed on the experience gained so far from different researchers in the literature and further research directions and proposals are discussed in great detail.

Recent advances in constructed wetland‐microbial fuel cells for simultaneous bioelectricity production and wastewater treatment: A review

“…The use of membranes in bioelectrochemical systems is essential to have a better control of the electrochemical reactions between the electrocatalytic enzymes and the substrate on anode surface . The proton exchange membranes (PEMs) are used as an electrolyte separator between the anodic and cathodic chamber when the cell is of double chamber, allowing the flow of protons from anode chamber to cathodic chamber.…”

“…The gravel bed is an inert material that can have different particle size and can allow different types of flow through of CW‐MFC. The gravel support is used in horizontal subsurface flow . Xu et al constructed three CW‐MFCs with different types of supporting materials: carbon felt as cathode and granular activated carbon as anode.…”

“…The CW‐MFC systems were originally designed for bioelectricity production from rhizodeposition, but this technology has been used for the wastewater treatment because although the power produced is low, it showed a promising capacity for wastewater treatment . The synergy between the organic matter oxidation and the bioelectricity production shows that a CW‐MFC plays an important role in the improved wastewater treatment, compared with traditional CW . The organic matter concentration greatly affects the CW‐MFC performance.…”

“…Within recent research, Nitisoravut and Regmi presented a review on the photosynthetic factors involved in the bioelectricity production and the types of plants that have been used. Wang et al presented the yields obtained on the removal of contaminants present in wastewater. Regmi et al presented the historical chronology of development of CW‐MFC as well as the biological and physicochemical factors that affect the performance of CW‐MFC.…”

Energy Storage Technologies for Off-grid Houses

“…In literature attempts have been reported to create off-grid, self-sufficient DWWTPs that are powered by renewable energy using technologies such as hydropower [132], wind turbines [133] , biomass [134], microbial fuel cells [135] and solar PV [136]. However, the implementation of these technologies as the only source of electricity for a DWWTP is still a challenge for large scale implementation.…”