Performance Evaluation of Microbial Fuel Cell Operated with Pd or MnO 2 as Cathode Catalyst and Chaetoceros Pretreated Anodic Inoculum

A review of microbial fuel cell and its diversification in the development of green energy technology

The advancement of microbial fuel cell technology is rapidly growing, with extensive research and well-established methodologies for enhancing structural performance. This terminology attracts researchers to compare the MFC devices on a technological basis. The architectural and scientific successes of MFCs are only possible with the knowledge of engineering and technical fields. This involves the structure of MFCs, using substrates and architectural backbones regarding electrode advancement, separators and system parameter measures. Knowing about the MFCs facilitates the systematic knowledge of engineering and scientific principles. The current situation of rapid urbanization and industrial growth is demanding the augmented engineering goods and production which results in unsolicited burden on traditional wastewater treatment plants. Consequently, posing health hazards and disturbing aquatic veracity due to partial and untreated wastewater. Therefore, it's sensible to evaluate the performance of MFCs as an unconventional treatment method over conventional one to treat the wastewater. However, MFCs some benefits like power generation, stumpy carbon emission and wastewater treatment are the main reasons behind the implementation. Nonetheless, few challenges like low power generation, scaling up are still the major areas needs to be focused so as to make MFCs sustainable one. We have focused on few archetypes which majorities have been laboratory scale in operations. To ensure the efficiency MFCs are needed to integrate and compatible with conventional wastewater treatment schemes. This review intended to explore the diversification in architecture of MFCs, exploration of MFCs ingredients and to provide the foreseen platform for the researchers in one source, so as to establish the channel for scaling up the technology. Further, the present review show that the MFC with different polymer membranes and cathode and anode modification presents significant role for potential commercial applications after change the system form prototype to pilot scale.

Nanoremediation strategies to address environmental problems

A rapid rise in population, extensive anthropogenic activities including agricultural practices, up-scaled industrialization, massive deforestation, etc. are the leading causes of environmental degradation. Such uncontrolled and unabated practices have affected the quality of environment (water, soil, and air) synergistically by accumulating huge quantities of organic and inorganic pollutants in it. Environmental contamination is posing a threat to the existing life on the Earth, therefore, demands the development of sustainable environmental remediation approaches. The conventional physiochemical remediation approaches are laborious, expensive, and time-consuming. In this regard, nanoremediation has emerged as an innovative, rapid, economical, sustainable, and reliable approach to remediate various environmental pollutants and minimize or attenuate the risks associated with them. Owing to their unique properties such as high surface area to volume ratio, enhanced reactivity, tunable physical parameters, versatility, etc. nanoscale objects have gained attention in environmental clean-up practices. The current review highlights the role of nanoscale objects in the remediation of environmental contaminants to minimize their impact on human, plant, and animal health; and air, water, and soil quality. The aim of the review is to provide information about the applications of nanoscale objects in dye degradation, wastewater management, heavy metal and crude oil remediation, and mitigation of gaseous pollutants including greenhouse gases.

Water with low ionic strength recovers the passivated birnessite-coated sand reactivity towards lincomycin removal

The ionic strength of infiltration water changes with the seasonal alternation of irrigation sources. In this study, reactivity changes of birnessite-coated sand with the fluctuations of ionic strength of infiltration water (i.e. from groundwater to rainwater) and the involved mechanism were investigated through column experiments. Birnessite-coated sand was less reactive in groundwater than in rainwater because of the higher cation content and higher pH of groundwater. The cations in the groundwater were adsorbed on birnessite-coated sand and then desorbed in presence of a dilute aqueous solution represented by rainwater. The reactivity of the passivated birnessite-coated sand was recovered instantaneously, and approximately one-third of the pristine reactivity was restored. During recovery, Na⁺ desorption and lincomycin (LIN) removal both exhibited a two-stage reaction pattern. The LIN removal correlated with Na⁺ desorption (r = 0.99) so that the reactive sites that were binding 5.602 μmol of Na⁺ became available for 1 μmol of LIN removal. These results suggest that the reactivity of manganese oxides toward organic contaminant is associated with the ionic strength of infiltration water and indicate that the partial reactivity can be naturally restored.

A Review of Recent Advances in Microbial Fuel Cells: Preparation, Operation, and Application

The microbial fuel cell has been considered a promising alternative to traditional fossil energy. It has great potential in energy production, waste management, and biomass valorization. However, it has several technical issues, such as low power generation efficiency and operational stability. These issues limit the scale-up and commercialization of MFC systems. This review presents the latest progress in microbial community selection and genetic engineering techniques for enhancing microbial electricity production. The summary of substrate selection covers defined substrates and some inexpensive complex substrates, such as wastewater and lignocellulosic biomass materials. In addition, it also includes electrode modification, electron transfer mediator selection, and optimization of operating conditions. The applications of MFC systems introduced in this review involve wastewater treatment, production of value-added products, and biosensors. This review focuses on the crucial process of microbial fuel cells from preparation to application and provides an outlook for their future development.

The use of marine microalgae in microbial fuel cells, photosynthetic microbial fuel cells and biophotovoltaic platforms for bioelectricity generation

Algal green energy has emerged as an alternative to conventional energy production using fossil fuels. Microbial fuel cells (MFCs), photosynthetic microbial fuel cells (PMFCs) and biophotovoltaic (BPV) platforms have been developed to utilize microalgae for bioelectricity generation, wastewater treatment and biomass production. There remains a lack of research on marine microalgae in these systems, so to the best of our knowledge, all information on their integration in these systems have been gathered in this review, and are used to compare with the interesting studies on freshwater microalgae. The performance of the systems is extremely reliant on the microalgae species and/or microbial community used, the size of the bio-electrochemical cell, and electrode material and distance used. The mean was calculated for each system, PMFC has the highest average maximum power density of 344 mW/m², followed by MFC (179 mW/m²) and BPV (58.9 mW/m²). In addition, the advantages and disadvantages of each system are highlighted. Although all three systems face the issue of low power outputs, the integration of a suitable energy harvester could potentially increase power efficiency and make them applicable for lower power applications.

Biodegradation of synthetic estrogen using bioelectrochemical system and degradation pathway analysis through Quadrupole-time-of-flight-mass spectrometry

Synthetic estrogenic compounds such as 17α-ethinylestradiol (EE2) are significant environmental contaminants. This research studied the biodegradation of EE2 utilizing the EE2 adapted cells isolated from a dairy farm waste site in suspension flask vis-a-vis Bioelectrochemical System (BES) and compared the power output in the BES with and without EE2 as a co-substrate. 78% removal of EE2 was observed in the BES as against 60% removal in suspension flasks. The maximum power density in the BES increased about 53% when EE2 is used as a co-substrate. The EE2 biodegradation studied using HPLC and Q-TOF methods, also proposes a hypothetical pathway for EE2 degradation by the newly isolated strain Rhodopseudomonas palustris MDOC01 and reports the significant metabolites like nicotinic acid and oxoproline being detected during bioelectrochemical treatment process of EE2. Study also suggests that Plasma peroxide treatment of anode material enhanced the overall performance in terms of biodegradation efficiency and power output.

Algae as potential feedstock for various bioenergy production

Depletion of non-renewable feedstock and severe wastewater pollution due to human activities have created negative impact to living organisms. The potential solution is to implement wastewater treatment and bioelectricity production through algae-based microbial fuel cell. The algae biomass produced from microbial fuel cell could be further processed to generate biofuels through their unique compositions. The consumption of nutrients in wastewater through algae cultivation and biomass produced to be utilized for energy supply have showed the potential of algae to solve the issues faced nowadays. This review introduces the background of algae and mitigation of wastewater using algae as well as the bioenergy status in Malaysia. The mechanisms of nutrient assimilation such as nitrogen, phosphorus, carbon, and heavy metals are included, followed by the application of algae in microbial fuel cell's chambers. Lastly, the status of algae for bioenergy production are covered.

Application of microbial electrochemical technologies for the treatment of petrochemical wastewater with concomitant valuable recovery: A review

Petrochemical industry is one of the major and rapidly growing industry that generates a variety of toxic and recalcitrant organic pollutants as by-products, which are not only harmful to the aquatic animals but also affects human health. The majority of the components of petrochemical wastewater (PW) are carcinogenic, genotoxic and phytotoxic in nature; hence, this complex wastewater generated from different petrochemical processes should be efficiently treated prior to its disposal in natural water bodies. The established technologies like advanced oxidation, membrane bioreactor, electrocoagulation and activated sludge process employed for the treatment of PW are highly energy intensive and incurs high capital and operation cost. Moreover, these technologies are not effective in completely eliminating petroleum hydrocarbons present in PW. Thus, to reduce the energy requirement and also to transform the chemical energy trapped in these organic matters present in this wastewater into bioelectricity and other value-added products, microbial electrochemical technologies (METs) can be efficaciously used, which would also compensate the treatment cost by transforming these pollutants into bioenergy and valuables. In this regard, this review elucidates the feasibility and application of different METs as an appropriate alternative for the treatment of PW. Furthermore, the numerous bottlenecks towards the real-life application and commercialization of pioneering METs have also been articulated.

Proficient Sanitary Wastewater Treatment in Laboratory and Field-Scale Microbial Fuel Cell with Anti-Biofouling Cu0.5Mn0.5Fe2O4 as Cathode Catalyst

For successful field-scale application of microbial fuel cell (MFC), the power recovery from field-scale MFC needs to be improved considerably with simultaneous reduction in its fabrication cost. These problems can be addressed by applying low-cost and efficient cathode catalyst in MFCs. In this regard, Cu0.5Mn0.5Fe2O4 (CuMnFe) was synthesized and applied as cathode catalyst in lab and field-scale MFCs with capacity of 150 ml and 25 l, respectively. Lab-scale MFC having CuMnFe as cathode catalyst demonstrated power density of 176.0 ± 8.2 mW m−2, which was competitive with MFC having Pt as cathode catalyst (183.0 ± 12.6 mW m−2) and it was about seven times higher than control MFC (25.5 ± 4.5 mW m−2) having no catalyst. Application of CuMnFe as cathode catalyst in field-scale MFC produced power density of 7.74 mW m−2, which was three-times higher than the power produced by the field-scale MFC operated without any cathode catalyst (2.58 mW m−2). The cathode catalyst CuMnFe also demonstrated excellent anti-biofouling properties, which in turn improved the power production of field-scale MFC. Therefore, low-cost CuMnFe can be anticipated as an efficacious cathode catalyst for application in MFCs that would produce long term stable higher power, while offering simultaneous treatment to wastewater.

Using easy-to-biodegrade co-substrate to eliminate microcystin toxic on electrochemically active bacteria and enhance bioelectricity generation from cyanobacteria biomass

Cyanobacterial biomass is a promising natural resource for power generation, through the reactions bio-catalyzed by electrochemically active bacteria (EAB). However, the major limitation is the involvement of Microcystin-LR (MC-LR) in inhibiting EAB activation. In this work, toxic M. aeruginosa biomass was employed as analyte of a microbial fuel cell (MFC), and sodium acetate was applied as easy-to-biodegrade co-substrate to alleviate the MC-LR stress on EAB survival. The running stability was continuously enhanced with the increment of co-substrate concentration. The sufficient co-substrate supply (6.0 mM) eliminated the negative effects of MC-LR on the cyanobacteria biomass fed-MFC performance; it contributed 12.7% extension on the electric cyclic terms and caused the productions of the power density which was comparable and even 3.8% higher than its corresponding control (MFC treated with acetate alone). The co-substrate addition also increased coulombic efficiency by 60.1%, microcystin-LR removal efficiency increased by 64.7%, and diversified the microbial community with more species able to biodegrade the MC-LR, bio-transforming the metabolites and EAB. Microcystin-degrading bacteria, such as Sphingopyxis sp., Burkholderia-Paraburkholderia, and Bacillus sp., were remarkably increased, and EAB, including Shewanella sp., Desulfovibrio desulfuricans, Aeromonas hydrophila, were also much more enriched in co-substrate use protocol. Therefore, this study verified a co-substrate strategy for simultaneously eliminating MC-LR toxin and enhancing bioelectricity generation from cyanobacterial biomass via an MFC.