Substrate as the electron donor of bioelectrochemical system(BES) has fateful impacts on the microbial community composition of electroactive biofilm(EAB), via the selection upon functional microorganisms such as exoe...Substrate as the electron donor of bioelectrochemical system(BES) has fateful impacts on the microbial community composition of electroactive biofilm(EAB), via the selection upon functional microorganisms such as exoelectrogens, fermenters and methanogens, as well as their interactions. Electrochemical performance as the terminal reflects of electroactivity and the correspondence between community members have been summarized. Exoelectrogens responsible to the conversion towards electricity from their respective preferred substrates such as acetate, propionate, glucose and cellulose has been found to be finite in a small range, e.g., Geobacter, Shewanella and Pseudomonas. Their demands of micromolecular electron donors and the selective pressure of primary substrates facilitate the existence of competitive or cooperative biological processes to exoelectrogenesis. The inherent mechanisms of the dynamics of such interactions have been explored with electrochemical methods,defined co-culture experiments and community analysis. Complete view of the metabolic network in electroactive microbial communities has been shed light on, and appeals further investigation.展开更多
Bioelectrochemical systems(BES)have emerged as a dual-function technology for treating wastewater and recovering energy.A vital element of BES is the rapid formation and maintenance of electroactive biofilms(EABs).Pre...Bioelectrochemical systems(BES)have emerged as a dual-function technology for treating wastewater and recovering energy.A vital element of BES is the rapid formation and maintenance of electroactive biofilms(EABs).Previous attempts to accelerate EAB formation and improve electroactivities focused on enhancing the bacterial adhesion process while neglecting the rate-limiting step of the bacterial transport process.Here,we introduce membrane filtration into BES,establishing a dynamic membrane filtration system that enhances overall performance.We observed that optimal membrane flux considerably reduced the startup time for EAB formation.Specifically,EABs established under a 25 L m^(-2)h^(-1)flux(EAB_(25)LMH)had a formation time of 43.8±1.3 h,notably faster than the 51.4±1.6 h in the static state(EAB_(0)LMH).Additionally,EAB_(25)LMH exhibited a significant increase in maximum current density,approximately 2.2 times higher than EAB_(0)LMH.Pearson correlation analysis indicated a positive relationship between current densities and biomass quantities and an inverse correlation with startup time.Microbial analysis revealed two critical findings:(i)variations in maximum current densities across different filtration conditions were associated with redox-active substances and biomass accumulation,and(ii)the incorporation of a filtration process in EAB formation enhanced the proportion of viable cells and encouraged a more diverse range of electroactive bacteria.Moreover,the novel electroactive membrane demonstrated sustained current production and effective solid-liquid separation during prolonged operation,indicating its potential as a viable alternative in membrane-based systems.This approach not only provides a new operational model for BES but also holds promise for expanding its application in future wastewater treatment solutions.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.21876090,21577068)the Tianjin Research Program of Application Foundation and Advanced Technology(Grant No.18JCZDJC39400)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.C029188008)the 111 Program of the Ministry of Education of China(Grant No.T2017002)
文摘Substrate as the electron donor of bioelectrochemical system(BES) has fateful impacts on the microbial community composition of electroactive biofilm(EAB), via the selection upon functional microorganisms such as exoelectrogens, fermenters and methanogens, as well as their interactions. Electrochemical performance as the terminal reflects of electroactivity and the correspondence between community members have been summarized. Exoelectrogens responsible to the conversion towards electricity from their respective preferred substrates such as acetate, propionate, glucose and cellulose has been found to be finite in a small range, e.g., Geobacter, Shewanella and Pseudomonas. Their demands of micromolecular electron donors and the selective pressure of primary substrates facilitate the existence of competitive or cooperative biological processes to exoelectrogenesis. The inherent mechanisms of the dynamics of such interactions have been explored with electrochemical methods,defined co-culture experiments and community analysis. Complete view of the metabolic network in electroactive microbial communities has been shed light on, and appeals further investigation.
基金financially supported by the National Natural Science Foundation of China(52200059 and 22036004)“the Fundamental Research Funds for the Central Universities,”Nankai University(Grant 63231127).
文摘Bioelectrochemical systems(BES)have emerged as a dual-function technology for treating wastewater and recovering energy.A vital element of BES is the rapid formation and maintenance of electroactive biofilms(EABs).Previous attempts to accelerate EAB formation and improve electroactivities focused on enhancing the bacterial adhesion process while neglecting the rate-limiting step of the bacterial transport process.Here,we introduce membrane filtration into BES,establishing a dynamic membrane filtration system that enhances overall performance.We observed that optimal membrane flux considerably reduced the startup time for EAB formation.Specifically,EABs established under a 25 L m^(-2)h^(-1)flux(EAB_(25)LMH)had a formation time of 43.8±1.3 h,notably faster than the 51.4±1.6 h in the static state(EAB_(0)LMH).Additionally,EAB_(25)LMH exhibited a significant increase in maximum current density,approximately 2.2 times higher than EAB_(0)LMH.Pearson correlation analysis indicated a positive relationship between current densities and biomass quantities and an inverse correlation with startup time.Microbial analysis revealed two critical findings:(i)variations in maximum current densities across different filtration conditions were associated with redox-active substances and biomass accumulation,and(ii)the incorporation of a filtration process in EAB formation enhanced the proportion of viable cells and encouraged a more diverse range of electroactive bacteria.Moreover,the novel electroactive membrane demonstrated sustained current production and effective solid-liquid separation during prolonged operation,indicating its potential as a viable alternative in membrane-based systems.This approach not only provides a new operational model for BES but also holds promise for expanding its application in future wastewater treatment solutions.
