It has been recently suggested that Alcaligenes use a previously unknown pathway to convert ammonium into dinitrogen gas(Dirammox)via hydroxylamine(NH2OH).This fact alone already implies a significant decrease in the ...It has been recently suggested that Alcaligenes use a previously unknown pathway to convert ammonium into dinitrogen gas(Dirammox)via hydroxylamine(NH2OH).This fact alone already implies a significant decrease in the aeration requirements for the process,but the process would still be dependent on external aeration.This work studied the potential use of a polarised electrode as an electron acceptor for ammonium oxidation using the recently described Alcaligenes strain HO-1 as a model heterotrophic nitrifier.Results indicated that Alcaligenes strain HO-1 requires aeration for metabolism,a requirement that cannot be replaced for a polarised electrode alone.However,concomitant elimination of succinate and ammonium was observed when operating a previously grown Alcaligenes strain HO-1 culture in the presence of a polarised electrode and without aeration.The usage of a polarised electrode together with aeration did not increase the succinate nor the nitrogen removal rates observed with aeration alone.However,current density generation was observed along a feeding batch test representing an electron share of 3%of the ammonium removed in the presence of aeration and 16%without aeration.Additional tests suggested that hydroxylamine oxidation to dinitrogen gas could have a relevant role in the electron discharge onto the anode.Therefore,the presence of a polarised electrode supported the metabolic functions of Alcaligenes strain HO-1 on the simultaneous oxidation of succinate and ammonium.展开更多
The industrial adoption of microbial electrosynthesis(MES)is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs.In this study,a mixed microbial consortium originati...The industrial adoption of microbial electrosynthesis(MES)is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs.In this study,a mixed microbial consortium originating from an anaerobic digester operated under saline conditions(∼13 g L^(−1)NaCl)was adapted for acetate production from bicarbonate in galvanostatic(0.25 mA cm^(−2))H-type cells at 5,10,15,or 20 g L^(−1)NaCl concentration.The acetogenic communities were successfully enriched only at 5 and 10 g L^(−1)NaCl,revealing an inhibitory threshold of about 6 g L^(−1)Na^(+).The enriched planktonic communities were then used as inoculum for 3D printed,three-chamber cells equipped with a gas diffusion biocathode.The cells were fed with CO_(2)gas and operated galvanostatically(0.25 or 1.00 mA cm^(−2)).The highest production rate of 55.4 g m^(−2) d^(−1)(0.89 g L^(−1)d^(−1)),with 82.4%Coulombic efficiency,was obtained at 5 g L^(−1)NaCl concentration and 1 mA cm^(−2)applied current,achieving an average acetate production of 44.7 kg MWh−1.Scanning electron microscopy and 16S rRNA sequencing analysis confirmed the formation of a cathodic biofilm dominated by Acetobacterium sp.Finally,three 3D printed cells were hydraulically connected in series to simulate an MES stack,achieving three-fold production rates than with the single cell at 0.25 mA cm^(−2).This confirms that three-chamber MES cells are an efficient and scalable technology for CO_(2)bio-electro recycling to acetate and that moderate saline conditions(5 g L^(−1)NaCl)can help reduce their power demand while preserving the activity of acetogens.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funded through the European Union's Horizon 2020 project ELECTRA[no.826244]National Nature Science Foundation of China(grant no.31861133002)+1 种基金S.P is a Serra Húnter Fellow(UdGAG-575)acknowledges the funding from the ICREA Academia award.LEQUiA[2021-SGR-01352]and Ecoaqua[2021-SGR-01142]have been recognized as consolidated research groups by the Catalan Government.
文摘It has been recently suggested that Alcaligenes use a previously unknown pathway to convert ammonium into dinitrogen gas(Dirammox)via hydroxylamine(NH2OH).This fact alone already implies a significant decrease in the aeration requirements for the process,but the process would still be dependent on external aeration.This work studied the potential use of a polarised electrode as an electron acceptor for ammonium oxidation using the recently described Alcaligenes strain HO-1 as a model heterotrophic nitrifier.Results indicated that Alcaligenes strain HO-1 requires aeration for metabolism,a requirement that cannot be replaced for a polarised electrode alone.However,concomitant elimination of succinate and ammonium was observed when operating a previously grown Alcaligenes strain HO-1 culture in the presence of a polarised electrode and without aeration.The usage of a polarised electrode together with aeration did not increase the succinate nor the nitrogen removal rates observed with aeration alone.However,current density generation was observed along a feeding batch test representing an electron share of 3%of the ammonium removed in the presence of aeration and 16%without aeration.Additional tests suggested that hydroxylamine oxidation to dinitrogen gas could have a relevant role in the electron discharge onto the anode.Therefore,the presence of a polarised electrode supported the metabolic functions of Alcaligenes strain HO-1 on the simultaneous oxidation of succinate and ammonium.
基金This work was performed on the framework of the Science Foundation Ireland(SFI)Pathfinder Award on“Hybrid Bio-Solar Reactors for wastewater treatment and CO_(2)recycling”(award nr.19/FIP/ZE/7572 PF)PD is supported by the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement,project ATMESPHERE,No 101029266.SP is a Serra Hunter Fellow(UdG-AG-575)+4 种基金acknowledges the funding from the ICREA Academia award.LEQUIA has been recognised as a consolidated research group by the Catalan Government(2021-SGR-01352)UZI is supported by EPSRC(EP/P029329/1 and EP/V030515/1)VOF is supported by the Enterprise Ireland Technology Centres Programme(TC/2014/0016)Science Foundation Ireland(14/IA/2371,19/FFP/6746 and 16/RC/3889)DP acknowledges the support of the VIVALDI project that has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement 101000441.
文摘The industrial adoption of microbial electrosynthesis(MES)is hindered by high overpotentials deriving from low electrolyte conductivity and inefficient cell designs.In this study,a mixed microbial consortium originating from an anaerobic digester operated under saline conditions(∼13 g L^(−1)NaCl)was adapted for acetate production from bicarbonate in galvanostatic(0.25 mA cm^(−2))H-type cells at 5,10,15,or 20 g L^(−1)NaCl concentration.The acetogenic communities were successfully enriched only at 5 and 10 g L^(−1)NaCl,revealing an inhibitory threshold of about 6 g L^(−1)Na^(+).The enriched planktonic communities were then used as inoculum for 3D printed,three-chamber cells equipped with a gas diffusion biocathode.The cells were fed with CO_(2)gas and operated galvanostatically(0.25 or 1.00 mA cm^(−2)).The highest production rate of 55.4 g m^(−2) d^(−1)(0.89 g L^(−1)d^(−1)),with 82.4%Coulombic efficiency,was obtained at 5 g L^(−1)NaCl concentration and 1 mA cm^(−2)applied current,achieving an average acetate production of 44.7 kg MWh−1.Scanning electron microscopy and 16S rRNA sequencing analysis confirmed the formation of a cathodic biofilm dominated by Acetobacterium sp.Finally,three 3D printed cells were hydraulically connected in series to simulate an MES stack,achieving three-fold production rates than with the single cell at 0.25 mA cm^(−2).This confirms that three-chamber MES cells are an efficient and scalable technology for CO_(2)bio-electro recycling to acetate and that moderate saline conditions(5 g L^(−1)NaCl)can help reduce their power demand while preserving the activity of acetogens.
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.
