Microbial electrochemical technologies(MET)can remove a variety of organic and inorganic pollutants from contaminated groundwater.However,despite significant laboratory-scale successes over the past decade,field-scale...Microbial electrochemical technologies(MET)can remove a variety of organic and inorganic pollutants from contaminated groundwater.However,despite significant laboratory-scale successes over the past decade,field-scale applications remain limited.We hypothesize that enhancing the electrochemical conductivity of the soil surrounding electrodes could be a groundbreaking and cost-effective alternative to deploying numerous high-surface-area electrodes in short distances.This could be achieved by injecting environmentally safe iron-or carbon-based conductive(nano)particles into the aquifer.Upon transport and deposition onto soil grains,these particles create an electrically conductive zone that can be exploited to control and fine-tune the delivery of electron donors or acceptors over large distances,thereby driving the process more efficiently.Beyond extending the radius of influence of electrodes,these diffuse electro-conductive zones(DECZ)could also promote the development of syntrophic anaerobic communities that degrade contaminants via direct interspecies electron transfer(DIET).In this review,we present the state-of-the-art in applying conductive materials for MET and DIET-based applications.We also provide a comprehensive overview of the physicochemical properties of candidate electrochemically conductive materials and related injection strategies suitable for field-scale implementation.Finally,we illustrate and critically discuss current and prospective electrochemical and geophysical methods for measuring soil electronic conductivitydboth in the laboratory and in the fielddbefore and after injection practices,which are crucial for determining the extent of DECZ.This review article provides critical information for a robust design and in situ implementation of groundwater electro-bioremediation processes.展开更多
Bioremediation of groundwater contaminated by a mixture of aromatic hydrocarbons and chlorinated solvents is typically challenged because these contaminants are degraded via distinctive oxidative and reductive pathway...Bioremediation of groundwater contaminated by a mixture of aromatic hydrocarbons and chlorinated solvents is typically challenged because these contaminants are degraded via distinctive oxidative and reductive pathways,thus requiring different amendments and redox conditions.Here,we provided the proof-of-concept of a single-stage treatment of synthetic groundwater containing toluene and trichloroethene(TCE)in a tubular bioelectrochemical reactor,known as a“bioelectric well”.Toluene was degraded by a microbial bioanode(up to 150 mmol L^(-1) d^(-1))with a polarized graphite anode(t0.2 V vs.SHE)serving as the terminal electron acceptor.The electric current deriving from microbially-driven toluene oxidation resulted in(abiotic)hydrogen production(at a stainless-steel cathode),which sustained the reductive dechlorination of TCE to less-chlorinated intermediates(i.e.,cis-DCE,VC,and ETH),at a maximum rate of 500 meq L^(-1) d^(-1),in the bulk of the reactor.A phylogenetic and functional genebased analysis of the“bioelectric well”confirmed the establishment of a microbiome harboring the metabolic potential for anaerobic toluene oxidation and TCE reductive dechlorination.However,Toluene degradation and current generation were found to be rate-limited by external mass transport phenomena,thus indicating the existing potential for further process optimization.展开更多
Lack of suitable electron donors or acceptors is in many cases the key reason for pollutants to persist in the environment.Externally supplementation of electron donors or acceptors is often difficult to control and/o...Lack of suitable electron donors or acceptors is in many cases the key reason for pollutants to persist in the environment.Externally supplementation of electron donors or acceptors is often difficult to control and/or involves chemical additions with limited lifespan,residue formation or other adverse side effects.Microbial electrochemistry has evolved very fast in the past years–this field relates to the study of electrochemical interactions between microorganisms and solid-state electron donors or acceptors.Current can be supplied in such so-called bioelectrochemical systems(BESs)at low voltage to provide or extract electrons in a very precise manner.A plethora of metabolisms can be linked to electrical current now,from metals reductions to denitrification and dechlorination.In this perspective,we provide an overview of the emerging applications of BES and derived technologies towards the bioremediation field and outline how this approach can be game changing.展开更多
基金support under the National Recovery and Resilience Plan(NRRP)Mission 4,Component 2,Investment 1.1,Call for tender No.104 published on February 2,2022 by the Italian Ministry of University and Research(MUR)+2 种基金funded by the European Union e Next GenerationEUe Project Title SteeRing GroundwatEr Electro-bioremediAtion with ConducTIVe ParticlEs(REACTIVE)e CUP:B53D23018110006-Grant Assignment Decree No.1048 adopted on July 14,2023 by the Italian Ministry of University and Research(MUR).UM acknowledges Villum Foundation(grant n.VIL50414)the Grundfos Foundation(grant n.2017-025)LP and GC acknowledge The Geosciences for Sustainable Development project(Budget Ministero dell'Universita e della Ricerca-Dipartimenti di Eccellenza 2023-2027,C93C23002690001).
文摘Microbial electrochemical technologies(MET)can remove a variety of organic and inorganic pollutants from contaminated groundwater.However,despite significant laboratory-scale successes over the past decade,field-scale applications remain limited.We hypothesize that enhancing the electrochemical conductivity of the soil surrounding electrodes could be a groundbreaking and cost-effective alternative to deploying numerous high-surface-area electrodes in short distances.This could be achieved by injecting environmentally safe iron-or carbon-based conductive(nano)particles into the aquifer.Upon transport and deposition onto soil grains,these particles create an electrically conductive zone that can be exploited to control and fine-tune the delivery of electron donors or acceptors over large distances,thereby driving the process more efficiently.Beyond extending the radius of influence of electrodes,these diffuse electro-conductive zones(DECZ)could also promote the development of syntrophic anaerobic communities that degrade contaminants via direct interspecies electron transfer(DIET).In this review,we present the state-of-the-art in applying conductive materials for MET and DIET-based applications.We also provide a comprehensive overview of the physicochemical properties of candidate electrochemically conductive materials and related injection strategies suitable for field-scale implementation.Finally,we illustrate and critically discuss current and prospective electrochemical and geophysical methods for measuring soil electronic conductivitydboth in the laboratory and in the fielddbefore and after injection practices,which are crucial for determining the extent of DECZ.This review article provides critical information for a robust design and in situ implementation of groundwater electro-bioremediation processes.
基金This study was supported by the European Union’s Horizon 2020 project ELECTRA(www.electra.site)under grant agreement No.826244.
文摘Bioremediation of groundwater contaminated by a mixture of aromatic hydrocarbons and chlorinated solvents is typically challenged because these contaminants are degraded via distinctive oxidative and reductive pathways,thus requiring different amendments and redox conditions.Here,we provided the proof-of-concept of a single-stage treatment of synthetic groundwater containing toluene and trichloroethene(TCE)in a tubular bioelectrochemical reactor,known as a“bioelectric well”.Toluene was degraded by a microbial bioanode(up to 150 mmol L^(-1) d^(-1))with a polarized graphite anode(t0.2 V vs.SHE)serving as the terminal electron acceptor.The electric current deriving from microbially-driven toluene oxidation resulted in(abiotic)hydrogen production(at a stainless-steel cathode),which sustained the reductive dechlorination of TCE to less-chlorinated intermediates(i.e.,cis-DCE,VC,and ETH),at a maximum rate of 500 meq L^(-1) d^(-1),in the bulk of the reactor.A phylogenetic and functional genebased analysis of the“bioelectric well”confirmed the establishment of a microbiome harboring the metabolic potential for anaerobic toluene oxidation and TCE reductive dechlorination.However,Toluene degradation and current generation were found to be rate-limited by external mass transport phenomena,thus indicating the existing potential for further process optimization.
基金funded through the European Union’s Horizon 2020 project ELECTRA under grant agreement No.826244National Natural Science Foundation of China(NSFC)(No.31861133001,31861133002,31861133003)+3 种基金Serra Hunter Fellow(UdG-AG-575)the funding from the ICREA Academia awarthe Catalan Government with code 2017-SGR-1552supported by the Ghent University special research fund under grant No.BOF19/GOA/026.
文摘Lack of suitable electron donors or acceptors is in many cases the key reason for pollutants to persist in the environment.Externally supplementation of electron donors or acceptors is often difficult to control and/or involves chemical additions with limited lifespan,residue formation or other adverse side effects.Microbial electrochemistry has evolved very fast in the past years–this field relates to the study of electrochemical interactions between microorganisms and solid-state electron donors or acceptors.Current can be supplied in such so-called bioelectrochemical systems(BESs)at low voltage to provide or extract electrons in a very precise manner.A plethora of metabolisms can be linked to electrical current now,from metals reductions to denitrification and dechlorination.In this perspective,we provide an overview of the emerging applications of BES and derived technologies towards the bioremediation field and outline how this approach can be game changing.
