A Sustainable Approach for the Production of Green Energy With the Holistic Treatment of Wastewater Through Microbial Electrochemical Technologies: A Review

Abstract

With the plausible depletion of fossil fuels in the near future and its associated environmental impacts, researchers have instigated the search for eco-friendly renewable bioenergy. Moreover, the increase in water pollution by industrial and anthropogenic activities is another alarming global concern. In this regard, the production of renewable and sustainable green bioenergy utilizing wastewater through microbial electrochemical technologies (METs) can alleviate these crucial problems by providing a sustainable solution to meet both the demands of energy and fresh water supply. Moreover, different bio-centered techniques such as nitrification and denitrification for nitrogen removal, and elimination of carcinogenic metals, pathogens, and organic components utilizing microbiota followed by toxicity sensing of different pollutants have been efficaciously exhibited through METs. However, inferior bioenergy production and recovery of low biomass yield in METs with high operational cost are noteworthy bottlenecks that hinder the scalability of this technology. Therefore, this review elaborates different physicochemical factors affecting the performance of METs, microbial interaction for the development of stable biofilm and so forth. Moreover, a broad overview on the production of bioenergy, along with the removal of pollutants from wastewater through different types of METs are also highlighted. Furthermore, the production of biofuels like ethanol, methanol, biodiesel, and gaseous fuel like bio-H2 coupled with power generation using photosynthetic microorganisms via CO2 sequestration through METs are also discussed. Additionally, recent developments with future scope for the field-scale implementation of METs along with their bottlenecks have been discussed, which has not been critically reviewed to date.

Efficient algal lipid extraction via a green bio-electro-Fenton process and its conversion into biofuel and bioelectricity with concurrent wastewater treatment in a photosynthetic microbial fuel cell

“…28 Moreover, the quantity of chemical energy that was converted into electrical energy through the PMFCs from the theoretical maximum electrical energy was estimated via coulombic efficiency (CE). 29 The operating voltage (OV) across 100 Ω of external resistance and open circuit voltage (OCV) under no current flowing conditions for the four PMFCs were periodically recorded using a data acquisition/switch unit (Agilent Technologies, Penang, Malaysia) coupled with a computer system. The data for polarisation graphs were generated by varying the external resistance from 50 kΩ to 10 Ω using a resistance box (GEC05R Decade Resistance Box, Bengaluru, India).…”

Role of bacterial quorum sensing and quenching mechanism in the efficient operation of microbial electrochemical technologies: A state-of-the-art review

“…The QSMs control cell-cell communication and aid in electron exchange in METs via biofilm formation, whereas the QQMs regulate the thickness of biofilms to optimise effluent treatment and value-added product recovery [ 17 ]. Bacterial biofilm formation in the anodic chamber of the MFC increases the rate of degradation of organics and electron exchange, which is advantageous for METs [ 18 ]. However, thick anodic biofilms reduce electron transportation as the bacteria in the inner layers do not have as much access to the substrate compared to the ones on the outer surface, accompanied by the loss of substrate from the outer to inner layers of the biofilm [ 19 ].…”

The Effects of Wheat and Rice Straw as a Substrate on the Treatment of Reverse Osmosis Reject Wastewater in a Single Chamber Microbial Fuel Cell

“…[1] MFCs are capable of treating wastewater along with simultaneous recovery of the bioenergy and other valuables from wastewater. [1,2] Extensive research in recent years has also shown that MFCs could be used to generate bioelectricity from a diverse array of substrates, from simple sugars to complex carbohydrates to complex waste products, such as various types of wastewaters. [2,3] Power densities of up to 1.5 kW/m 3 have been achieved due to advancements in latest electrode materials and reactor layouts.…”

“…The microbial fuel cell (MFC) is a technique used to convert carbon‐rich waste into bioelectricity by utilizing the ability of some microorganisms, known as exoelectrogens, to move electrons outside the cell [1] . MFCs are capable of treating wastewater along with simultaneous recovery of the bioenergy and other valuables from wastewater [1,2] .…”

“…The microbial fuel cell (MFC) is a technique used to convert carbon‐rich waste into bioelectricity by utilizing the ability of some microorganisms, known as exoelectrogens, to move electrons outside the cell [1] . MFCs are capable of treating wastewater along with simultaneous recovery of the bioenergy and other valuables from wastewater [1,2] . Extensive research in recent years has also shown that MFCs could be used to generate bioelectricity from a diverse array of substrates, from simple sugars to complex carbohydrates to complex waste products, such as various types of wastewaters [2,3] .…”