Discover insights from thousands of peer-reviewed papers on microbial electrochemical systems
Frontiers in Microbiology · 2015
Acetate is a major product of fermentation processes and an important substrate for sulfate reducing bacteria and methanogenic archaea. Most studies on acetate catabolism by sulfate reducers and methanogens have used pure cultures. Less is known about acetate conversion by mixed pure cultures and the interactions between both groups. We tested interspecies hydrogen transfer and coexistence between marine methanogens and sulfate reducers using mixed pure cultures of two types of microorganisms. First, Desulfovibrio vulgaris subsp. vulgaris (DSM 1744), a hydrogenotrophic sulfate reducer, was cocultured together with the obligate aceticlastic methanogen Methanosaeta concilii using acetate as carbon and energy source. Next, Methanococcus maripaludis S2, an obligate H2- and formate-utilizing methanogen, was used as a partner organism to M. concilii in the presence of acetate. Finally, we performed a coexistence experiment between M. concilii and an acetotrophic sulfate reducer Desulfobacter latus AcSR2. Our results showed that D. vulgaris was able to reduce sulfate and grow from hydrogen leaked by M. concilii. In the other coculture, M. maripaludis was sustained by hydrogen leaked by M. concilii as revealed by qPCR. The growth of the two aceticlastic microbes indicated co-existence rather than competition. Altogether, our results indicate that H2 leaking from M. concilii could be used by efficient H2-scavengers. This metabolic trait, revealed from coculture studies, brings new insight to the metabolic flexibility of methanogens and sulfate reducers residing in marine environments in response to changing environmental conditions and community compositions. Using dedicated physiological studies we were able to unravel the occurrence of less obvious interactions between marine methanogens and sulfate-reducing bacteria.
Chemical Engineering Journal · 2016
Separation and Purification Technology · 2022
Environment International · 2020
Groundwater contamination is an ever-growing environmental issue that has attracted much and undiminished attention for the past half century. Groundwater contamination may originate from both anthropogenic (e.g., hydrocarbons) and natural compounds (e.g., nitrate and arsenic); to tackle the removal of these contaminants, different technologies have been developed and implemented. Recently, bioelectrochemical systems (BES) have emerged as a potential treatment for groundwater contamination, with reported in situ applications that showed promising results. Nitrate and hydrocarbons (toluene, phenanthrene, benzene, BTEX and light PAHs) have been successfully removed, due to the interaction of microbial metabolism with poised electrodes, in addition to physical migration due to the electric field generated in a BES. The selection of proper BESs relies on several factors and problems, such as the complexity of groundwater and subsoil environment, scale-up issues, and energy requirements that need to be accounted for. Modeling efforts could help predict case scenarios and select a proper design and approach, while BES-based biosensing could help monitoring remediation processes. In this review, we critically analyze in situ BES applications for groundwater remediation, focusing in particular on different proposed setups, and we identify and discuss the existing research gaps in the field.
Microorganisms · 2016
Polyhydroxyalkanoate (PHA) biopolymers are widely recognised as outstanding candidates to replace conventional petroleum-derived polymers. Their mechanical properties are good and can be tailored through copolymer composition, they are biodegradable, and unlike many alternatives, they do not rely on oil-based feedstocks. Further, they are the only commodity polymer that can be synthesised intracellularly, ensuring stereoregularity and high molecular weight. However, despite offering enormous potential for many years, they are still not making a significant impact. This is broadly because commercial uptake has been limited by variable performance (inconsistent polymer properties) and high production costs of the raw polymer. Additionally, the main type of PHA produced naturally is poly-3-hydroxybutyrate (PHB), which has limited scope due to its brittle nature and low thermal stability, as well as its tendency to embrittle over time. Production cost is strongly impacted by the type of the feedstock used. In this article we consider: the production of PHAs from methanotrophs using methane as a cost-effective substrate; the use of mixed cultures, as opposed to pure strains; and strategies to generate a poly(3-hydroxybutyrate-co-3-hydroxyvalerate) copolymer (PHBV), which has more desirable qualities such as toughness and elasticity.
Journal of the American Chemical Society · 2017
Factors governing the photoelectrochemical output of photosynthetic microorganisms are poorly understood, and energy loss may occur due to inefficient electron transfer (ET) processes. Here, we systematically compare the photoelectrochemistry of photosystem II (PSII) protein-films to cyanobacteria biofilms to derive: (i) the losses in light-to-charge conversion efficiencies, (ii) gains in photocatalytic longevity, and (iii) insights into the ET mechanism at the biofilm interface. This study was enabled by the use of hierarchically structured electrodes, which could be tailored for high/stable loadings of PSII core complexes and Synechocystis sp. PCC 6803 cells. The mediated photocurrent densities generated by the biofilm were 2 orders of magnitude lower than those of the protein-film. This was partly attributed to a lower photocatalyst loading as the rate of mediated electron extraction from PSII in vitro is only double that of PSII in vivo. On the other hand, the biofilm exhibited much greater longevity (>5 days) than the protein-film (<6 h), with turnover numbers surpassing those of the protein-film after 2 days. The mechanism of biofilm electrogenesis is suggested to involve an intracellular redox mediator, which is released during light irradiation.
Bioresource Technology · 2016
Biotechnology Notes · 2024
The excessive discharge and accumulation of solid organic waste into the environment is of severe concern across the globe. Thus, an efficient waste management system is important to mitigate health risks to humans, minimize harmful impacts on the environment, and ensure a sustainable ecosystem. The organic waste is converted into value-added products either using microorganisms or heat energy; these methods are commonly known as biochemical and thermochemical techniques. The biochemical process has the advantage of higher selectivity of the products and lower processing temperatures. The principal conversion processes of this category are fermentation and anaerobic digestion (AD). This review article focuses on AD, a potential method for treating organic waste and creating a variety of products with added value. Here we present the digestibility of various organic wastes, the role of microorganisms, the decomposition process, co-substrates, digester designs, biogas yields, by-products, environmental impacts, and overall techno-economical effectiveness of the process. Further, this review offers insights into new directions for AD for waste treatment and future research without compromising the overall feasibility and environmental sustainability.
Water Air & Soil Pollution · 2021
Abstract Remediation of contaminated soil and sediment is important for improving the eco-environmental quality. Electro-kinetic remediation (EKR) is an environmentally friendly technology to migrate and remove pollutants from the soil and sediment matrix. This paper analyses the mechanism and performance of EKR of heavy metals, organic pollutants, and compound pollutants. Moreover, the effect of optimizing individual EKR through soil and sediment pre-treatment (adding acid/oxidant/co-solvent/surfactant, stirring, heating, etc.), electrode optimization (exchange electrode, anode approximation, electrode matrix, etc.), and applying multi-technology combination (electro-kinetic permeable reaction barrier/Fenton/ion, exchange membrane/ultrasonic/electrolyte enhancement, etc.) was evaluated. Factors including incomplete separation of pollutants, variation in physico-chemical properties and microstructure of soil/sediment, and difficulties in in situ practice have restrained the field application of EKR. To solve the above technical challenge, an integrated EKR technology based on pollutant in situ separation, followed by separated contaminant treatment, and subsequent valuable elements recovery is proposed.
Bioresource Technology · 2015
Bioresource Technology · 2019
IEEE Access · 2024
The decarbonization of hard-to-abate industries is crucial for keeping global warming to below 2°C. Green or renewable hydrogen, synthesized through water electrolysis, has emerged as a sustainable alternative for fossil fuels in energy-intensive sectors such as aluminum, cement, chemicals, steel, and transportation. However, the scalability of green hydrogen production faces challenges including infrastructure gaps, energy losses, excessive power consumption, and high costs throughout the value chain. Therefore, this study analyzes the challenges within the green hydrogen value chain, focusing on the development of nascent technologies. Presenting a comprehensive synthesis of contemporary knowledge, this study assesses the potential impacts of green hydrogen on hard-to-abate sectors, emphasizing the expansion of clean energy infrastructure. Through an exploration of emerging renewable hydrogen technologies, the study investigates aspects such as economic feasibility, sustainability assessments, and the achievement of carbon neutrality. Additionally, considerations extend to the potential for large-scale renewable electricity storage and the realization of net-zero goals. The findings of this study suggest that emerging technologies have the potential to significantly increase green hydrogen production, offering affordable solutions for decarbonization. The study affirms that global-scale green hydrogen production could satisfy up to 24% of global energy needs by 2050, resulting in the abatement of 60 gigatons of greenhouse gas (GHG) emissions - equivalent to 6% of total cumulative <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">CO</i> <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> emission reductions. To comprehensively evaluate the impact of the hydrogen economy on ecosystem decarbonization, this article analyzes the feasibility of three business models that emphasize choices for green hydrogen production and delivery. Finally, the study proposes potential directions for future research on hydrogen valleys, aiming to foster interconnected hydrogen ecosystems.
Renewable and Sustainable Energy Reviews · 2019
Energy · 2020
Bioresource Technology · 2023
Sustainable Water Resources Management · 2023
Water Research · 2021
Scientific Reports · 2015
The MoS2 and reduced graphite oxide (rGO) composite has attracted intensive attention due to its favorable performance as hydrogen evolution reaction (HER) catalyst, but still lacking is the theoretical understanding from a dynamic perspective regarding to the influence of electron transfer, as well as the connection between conductivity and the promoted HER performance. Based on the first-principles calculations, we here clearly reveal how an excess of negative charge density affects the variation of Gibbs free energy (ΔG) and the corresponding HER behavior. It is demonstrated that the electron plays a crucial role in the HER routine. To verify the theoretical analyses, the MoS2 and reduced graphite oxide (rGO) composite with well defined 3-dimensional configuration was synthesized via a facile one-step approach for the first time. The experimental data show that the HER performance have a direct link to the conductivity. These findings pave the way for a further developing of 2-dimension based composites for HER applications.
Bioelectrochemistry · 2017
Bioresource Technology · 2021
Electrochimica Acta · 2016
Bioresource Technology · 2015
Scientific Reports · 2015
This study investigated the interaction of the macrophyte Acorus calamus and sediment microbial fuel cells (SMFC) during the degradation of high molecular weight-polycyclic aromatic hydrocarbons (HMW-PAHs) in sediments. Over 367-days, the combination of macrophyte and SMFC led to an increase in pyrene and benzo[a]pyrene degradation rates by at least 70% compared to SMFC or macrophyte alone. While either the macrophyte or SMFC increased redox potential in sediments, redox potentials near the anode (approximately 6 cm depth) in the macrophyte-SMFC combination were markedly lower than that in the only macrophyte treatment. Moreover, rhizospheric bacterial communities in macrophyte-SMFC and macrophyte treatments were distinctly different. Aerobic genera (Vogesella, Pseudomonas, Flavobacterium and Rhizobium) and anaerobic genera (Longilinea, Bellilinea, Desulfobacca and Anaeromyxobacter) became dominant in the rhizosphere in macrophyte and macrophyte-SMFC treatments, respectively. In addition, the macrophyte-SMFC combination improved the numbers of not only aerobic but anaerobic PAHs degraders in sediments. So, the SMFC employment facilitated the formation of anoxic zones in sediments with oxygen loss and exudates from the roots. As a result, cooperation of anaerobic/aerobic microbial metabolism for accelerating HMW-PAHs removal occurred within sediments after combining macrophytes with SMFC.
Process Biochemistry · 2018
Membranes · 2020
In the context of preserving and improving human health, electrodialytic processes are very promising perspectives. Indeed, they allow the treatment of water, preservation of food products, production of bioactive compounds, extraction of organic acids, and recovery of energy from natural and wastewaters without major environmental impact. Hence, the aim of the present review is to give a global portrait of the most recent developments in electrodialytic membrane phenomena and their uses in sustainable strategies. It has appeared that new knowledge on pulsed electric fields, electroconvective vortices, overlimiting conditions and reversal modes as well as recent demonstrations of their applications are currently boosting the interest for electrodialytic processes. However, the hurdles are still high when dealing with scale-ups and real-life conditions. Furthermore, looking at the recent research trends, potable water and wastewater treatment as well as the production of value-added bioactive products in a circular economy will probably be the main applications to be developed and improved. All these processes, taking into account their principles and specificities, can be used for specific eco-efficient applications. However, to prove the sustainability of such process strategies, more life cycle assessments will be necessary to convince people of the merits of coupling these technologies.
Environmental Science and Ecotechnology · 2023
-based materials and guiding the development of efficient photocatalysts.
Advanced Composites and Hybrid Materials · 2023
Abstract Additive manufacturing (AM) also known as 3D printing (3DP) has become a popular technology with a wide range of applications, from which vat photopolymerization is a technique for producing nanocomposites with controlled mechanical, thermal, and electrical properties. This technology uses a UV light laser to cure a liquid resin into a solid object, layer by layer, allowing complex three-dimensional (3D) objects with intricate details of manufacturing and excellent finishing. Nanocomposites produced by vat photopolymerization have been used in aerospace, automotive, and medical industries, due to their superior mechanical strength and dimensional accuracy. In this article, we will discuss the advantages and other aspects of nanocomposites made with vat photopolymerization, exploring potential applications, and discuss the research by different areas, such as their AM technologies and materials properties. Graphical abstract This review deals with nanocomposites made by additive manufacturing (3D printing), presenting a systematic on vat photopolymerization technology, including the technologies, materials, and properties.
ACS Catalysis · 2021
Seawater electrolysis is an attractive approach for producing clean hydrogen fuel in scenarios where freshwater is scarce and renewable electricity is abundant. However, chloride ions (Cl–) in seawater can accelerate electrode corrosion and participate in the undesirable chlorine evolution reaction (CER). This problem is especially acute in acidic conditions that naturally arise at the anode as a result of the desired oxygen evolution reaction (OER). Herein, we demonstrate that ultrathin silicon oxide (SiOx) overlayers on model platinum anodes are highly effective at suppressing the CER in the presence of 0.6 M Cl– in both acidic and unbuffered pH-neutral electrolytes by blocking the transport of Cl– to the catalytically active buried interface while allowing the desired oxygen evolution reaction (OER) to occur there. The permeability of Cl– in SiOx overlayers is 3 orders of magnitude less than that of Cl– in a conventional salt-selective membrane used in reverse osmosis desalination. The overlayers also exhibit robust stability over 12 h in chronoamperometry tests at moderate overpotentials. SiOx overlayers demonstrate a promising step toward achieving selective and stable seawater electrolysis without the need to adjust the pH of the electrolyte.
Water Environment Research · 2019
Worldwide waste generation has become a topic of interest since the accumulation of this waste has prompted environmental hazards. Among which, anaerobic digestion provides green and efficient alternate solution for removal of toxic waste and energy production. Therefore, this review emphasizes on the recent data published in 2018 on topics related to anaerobic process, enhancement of biogas production, and fermentation efficiency. Furthermore, more focus was made on the factors influencing anaerobic digestion and the effect of trace elements as ionic salts as well as nanoparticles on overall biogas production, respectively. PRACTITIONER POINTS: Anaerobic digestion provide green and efficient alternate solution to deal with. This review focused on the conditions related to anaerobic process to improve biogas production and fermentation efficiency. The trace elements were focused on how to influence biogas production during anaerobic digestion.
Food Security · 2019
Edible microbial biomass derived from bacteria, yeasts, filamentous fungi or microalgae is a promising alternative to conventional sources of food and feed. Microorganisms are a good source of protein, vitamins and, in some cases, also contain beneficial lipids. The ability of microorganisms to use simple organic substrates for growth permits industrial-scale cultivation of edible microbial biomass in geographical locations that would not compete with agricultural production. Only a handful of microbial products are currently available for human consumption. The use of microbial biomass for animal feed is limited by access to low-cost growth substrates and competition from conventional feed sources such as soy and fishmeal. At a time when the global food production system is threatened by the effects of climate change, the production of edible microorganisms has the potential to circumvent many of the current environmental boundaries of food production as well as reducing its environmental impact. Photosynthetic microorganisms such as cyanobacteria and microalgae can be cultivated for food and feed independently of arable land. In addition, recent technological developments in atmospheric carbon dioxide (CO2) capture, extraction and catalytic conversion into simple organic compounds can be used for cultivation of edible microbial biomass for food and feed in a manner that is wholly independent of photosynthesis. The future possibilities, challenges and risks of scaled-up production of edible microbial biomass in relation to the global food system and the environment are discussed.
ChemBioEng Reviews · 2019
Abstract Renewable methanol production is an emerging technology that bridges the gap in the shift from fossil fuel to renewable energy. Two thirds of the global emission of CO 2 stems from humanity's increasing energy need from fossil fuels. Renewable energy, mainly from solar and wind energy, suffers from supply intermittency, which current grid infrastructures cannot accommodate. Excess renewable energy can be harnessed to power the electrolysis of water to produce hydrogen, which can be used in the catalytic hydrogenation of waste CO 2 to produce renewable methanol. This review considers methanol production in the current context, regionally for Europe, which is dominated by Germany, and globally by China. Appropriate carbon‐based feedstock for renewable methanol production is considered, as well as state‐of‐the‐art renewable hydrogen production technologies. The economics of renewable methanol production necessitates the consideration of regionally relevant methanol derivatives. The thermodynamics, kinetics, catalytic reaction mechanism, operating conditions and reactor design are reviewed in the context of renewable methanol production to reveal the most up to date understanding.
Water Research · 2015
Bioresource Technology · 2019
Water Research · 2023
Bioresource Technology · 2019
Chemosphere · 2021
Frontiers in Microbiology · 2015
Microbial electrosynthesis, an artificial form of photosynthesis, can efficiently convert carbon dioxide into organic commodities; however, this process has only previously been demonstrated in reactors that have features likely to be a barrier to scale-up. Therefore, the possibility of simplifying reactor design by both eliminating potentiostatic control of the cathode and removing the membrane separating the anode and cathode was investigated with biofilms of Sporomusa ovata. S. ovata reduces carbon dioxide to acetate and acts as the microbial catalyst for plain graphite stick cathodes as the electron donor. In traditional 'H-cell' reactors, where the anode and cathode chambers were separated with a proton-selective membrane, the rates and columbic efficiencies of microbial electrosynthesis remained high when electron delivery at the cathode was powered with a direct current power source rather than with a potentiostat-poised cathode utilized in previous studies. A membrane-less reactor with a direct-current power source with the cathode and anode positioned to avoid oxygen exposure at the cathode, retained high rates of acetate production as well as high columbic and energetic efficiencies. The finding that microbial electrosynthesis is feasible without a membrane separating the anode from the cathode, coupled with a direct current power source supplying the energy for electron delivery, is expected to greatly simplify future reactor design and lower construction costs.
Bioresource Technology · 2018
Current Opinion in Environmental Sustainability · 2020
This paper summarizes key findings from a series of systematic reviews and comprehensive efforts to collate evidence and expert opinions on circular solutions for recovery and reuse of nutrients and carbon from different waste streams in the agriculture and wastewater sectors. We identify established and emerging approaches for transformation towards a more circular nutrient economy with relevance to SDGs 6 and 14. The paper cites the example of the Baltic Sea Region which has experienced decades of fertilizer overuse (1950s–1990s) and concomitant urban sources of excessive nutrients. Regulations and incentive policies combining the nitrogen, phosphorus and carbon cycles are necessary if circular nutrient technologies and practices are to be scaled up. Pricing chemical fertilizer at levels to reflect society’s call for circularity is a central challenge.
Heliyon · 2024
Microbial fuel cells (MFCs) are promising for generating renewable energy from organic matter and efficient wastewater treatment. Ensuring their practical viability requires meticulous optimization and precise design. Among the critical components of MFCs, the membrane separator plays a pivotal role in segregating the anode and cathode chambers. Recent investigations have shed light on the potential benefits of membrane-less MFCs in enhancing power generation. However, it is crucial to recognize that such configurations can adversely impact the electrocatalytic activity of anode microorganisms due to increased substrate and oxygen penetration, leading to decreased coulombic efficiency. Therefore, when selecting a membrane for MFCs, it is essential to consider key factors such as internal resistance, substrate loss, biofouling, and oxygen diffusion. Addressing these considerations carefully allows researchers to advance the performance and efficiency of MFCs, facilitating their practical application in sustainable energy production and wastewater treatment. Accelerated substrate penetration could also lead to cathode clogging and bacterial inactivation, reducing the MFC's efficiency. Overall, the design and optimization of MFCs, including the selection and use of membranes, are vital for their practical application in renewable energy generation and wastewater treatment. Further research is necessary to overcome the challenges of MFCs without a membrane and to develop improved membrane materials for MFCs. This review article aims to compile comprehensive information about all constituents of the microbial fuel cell, providing practical insights for researchers examining various variables in microbial fuel cell research.