The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising sol...The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising solution.Here,we introduce an ML technique based on multimodal strategies,focusing specifically on intelligent aeration control in wastewater treatment plants(WWTPs).The generalization of the multimodal strategy is demonstrated on eight ML models.The results demonstrate that this multimodal strategy significantly enhances model indicators for ML in environmental science and the efficiency of aeration control,exhibiting exceptional performance and interpretability.Integrating random forest with visual models achieves the highest accuracy in forecasting aeration quantity in multimodal models,with a mean absolute percentage error of 4.4%and a coefficient of determination of 0.948.Practical testing in a full-scale plant reveals that the multimodal model can reduce operation costs by 19.8%compared to traditional fuzzy control methods.The potential application of these strategies in critical water science domains is discussed.To foster accessibility and promote widespread adoption,the multimodal ML models are freely available on GitHub,thereby eliminating technical barriers and encouraging the application of artificial intelligence in urban wastewater treatment.展开更多
The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domai...The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift.展开更多
Mixed bacteria were enriched from heavy metals mine soil for cadmium(Cd(Ⅱ))-containing wastewater treatment. Batch adsorption experiment results showed that the optimal pH, temperature, initial Cd(Ⅱ) concentration, ...Mixed bacteria were enriched from heavy metals mine soil for cadmium(Cd(Ⅱ))-containing wastewater treatment. Batch adsorption experiment results showed that the optimal pH, temperature, initial Cd(Ⅱ) concentration, and biomass dosage were 6.0, 30 ℃, 20 mg/L, and 1 g/L, respectively. Living biomass exhibited better Cd(Ⅱ) removal efficiency(91.97%) than autoclaved biomass(79.54%) under optimal conditions. The isotherms and kinetics of living biomass conformed to the Langmuir isotherm model and pseudo-first-order kinetic model, respectively. FTIR results implied that amine groups, hydroxyl groups and phosphoric acid play an important role in the Cd(Ⅱ) adsorption process, while XRD results showed that crystalline Cd(OH)and CdO were obtained. After Cd(Ⅱ)-containing wastewater treatment exposure, the dominant bacteria genera included Comamonas(39.94%), unclassified_f__Enterobacteriaceae(34.96%), Ochrobactrum(14.07%), Alcaligenes(4.84%), Bordetella(2.07%), Serratia(1.04%), and Bacillus(1.01%). Function prediction showed that the abundance of metabolic genes changed significantly. This study proposes the potential application of mixed bacteria for Cd(Ⅱ)-containing wastewater treatment.展开更多
Energy recovery from low-strength wastewater through anaerobic methanogenesis is constrained by limited substrate availability.The development of efficient methanogenic communities is critical but challenging.Here we ...Energy recovery from low-strength wastewater through anaerobic methanogenesis is constrained by limited substrate availability.The development of efficient methanogenic communities is critical but challenging.Here we develop a strategy to acclimate methanogenic communities using conductive carrier(CC),electrical stress(ES),and Acid Orange 7(AO7)in a modified biofilter.The synergistic integration of CC,ES,and AO7 precipitated a remarkable 72-fold surge in methane production rate compared to the baseline.This increase was attributed to an altered methanogenic community function,independent of the continuous presence of AO7 and ES.AO7 acted as an external electron acceptor,accelerating acetogenesis from fermentation intermediates,restructuring the bacterial community,and enriching electroactive bacteria(EAB).Meanwhile,CC and ES orchestrated the assembly of the archaeal community and promoted electrotrophic methanogens,enhancing acetotrophic methanogenesis electron flow via a mechanism distinct from direct electrochemical interactions.The collective application of CC,ES,and AO7 effectively mitigated electron flow impediments in low-strength wastewater methanogenesis,achieving an additional 34%electron recovery from the substrate.This study proposes a new method of amending anaerobic digestion systems with conductive materials to advance wastewater treatment,sustainability,and energy self-sufficiency.展开更多
Remediating soil contaminated with polycyclic aromatic hydrocarbons(PAHs)presents a significant environmental challenge due to their toxic and carcinogenic properties.Traditional PAHs remediation methodsdchemical,ther...Remediating soil contaminated with polycyclic aromatic hydrocarbons(PAHs)presents a significant environmental challenge due to their toxic and carcinogenic properties.Traditional PAHs remediation methodsdchemical,thermal,and bioremediationdalong with conventional soil-washing agents like surfactants and cyclodextrins face challenges of cost,ecological harm,and inefficiency.Here we show an effective and environmentally friendly calixarene derivative for PAHs removal through soil washing.Thiacalix[4]arene tetrasulfonate(TCAS)has a unique molecular structure of a sulfonate group and a sulfur atom,which enhances its solubility and facilitates selective binding with PAHs.It forms host-guest complexes with PAHs through p-p stacking,OH-p interactions,hydrogen bonding,van der Waals forces,and electrostatic interactions.These interactions enable partial encapsulation of PAH molecules,aiding their desorption from the soil matrix.Our results show that a 0.7%solution of TCAS can extract approximately 50%of PAHs from contaminated soil while preserving soil nutrients and minimizing adverse environmental effects.This research unveils the pioneering application of TCAS in removing PAHs from contaminated soil,marking a transformative advancement in resource-efficient and sustainable soil remediation strategies.展开更多
As one of the typical emerging contaminants,microplastics exist widely in the environment because of their small size and recalcitrance,which has caused various ecological problems.This paper summarizes current adsorp...As one of the typical emerging contaminants,microplastics exist widely in the environment because of their small size and recalcitrance,which has caused various ecological problems.This paper summarizes current adsorption and removal technologies of microplastics in typical aquatic environments,including natural freshwater,marine,drinking water treatment plants(DWTPs),and wastewater treatment plants(WWTPs),and includes abiotic and biotic degradation technologies as one of the removal technologies.Recently,numerous studies have shown that enrichment technologies have been widely used to remove microplastics in natural freshwater environments,DWTPs,and WWTPs.Efficient removal of microplastics via WWTPs is critical to reduce the release to the natural environment as a key connection point to prevent the transfer of microplastics from society to natural water systems.Photocatalytic technology has outstanding pre-degradation effects on microplastics,and the isolated microbial strains or enriched communities can degrade up to 50%or more of pre-processed microplastics.Thus,more research focusing on microplastic degradation could be carried out by combining physical and chemical pretreatment with subsequent microbial biodegradation.In addition,the current recovery technologies of microplastics are introduced in this review.This is incredibly challenging because of the small size and dispersibility of microplastics,and the related technologies still need further development.This paper will provide theoretical support and advice for preventing and controlling the ecological risks mediated by microplastics in the aquatic environment and share recommendations for future research on the removal and recovery of microplastics in various aquatic environments,including natural aquatic environments,DWTPs,and WWTPs.展开更多
Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there ...Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there is still a limited understanding of how to match the Pd load and MnO_(2) to realize optimal dechlorination efficiency at minimum cost.Here,a Pd/MnO_(2)/Ni foam cathode was successfully fabricated and applied for the efficient electrochemical dechlorination of 2,4,6-trichlorophenol(2,4,6-TCP).The optimal electrocatalytic hydrodechlorination(ECH)performance with 2,4,6-TCP dechlorination efficiency(92.58%in 180 min)was obtained when the concentration of PdCl_(2) precipitation was 1 mmol/L,the deposition time of MnO_(2) was 300 s and cathode potential was-0.8 V.Performance influenced by the exogenous factors(e.g.,initial pH and coexisted ions)were further investigated.It was found that the neutral pH was the most favorable for ECH and a reduction in dechlorination efficiency(6%~47.6%)was observed in presence of 5 mmol/L of NO_(2)^(-),NO_(3)^(-),S^(2-)or SO_(3)^(2-).Cyclic voltammetry(CV)and quenching experiments verified the existence of three hydrogen species on Pd surface,including adsorbed atomic hydrogen(H^(*)_(ads)),absorbed atomic hydrogen(H^(*)_(abs)),and molecular hydrogen(H_(2)).And the introduction of MnO_(2)promoted the generation of atomic H^(*).Only adsorbed atomic hydrogen(H^(*)_(ads)) was confirmed that it truly facilitated the ECH process.Besides H^(*)_(ads) induced reduction,the direct reduction by cathode electrons also participated in the 2,4,6-TCP dechlorination process.Pd/MnO_(2)/Ni foam cathode shows excellent dechlorination performance,fine stability and recyclable potential,which provides strategies for the effective degradation of persistent halogenated organic pollutants in groundwater.展开更多
Bioelectrochemical systems(BESs)have been studied extensively during the past decades owing primarily to their versatility and potential in addressing the water-energy-resource nexus.In stark contrast to the significa...Bioelectrochemical systems(BESs)have been studied extensively during the past decades owing primarily to their versatility and potential in addressing the water-energy-resource nexus.In stark contrast to the significant advancements that have been made in developing innovative processes for pollution control and bioresource/bioenergy recovery,minimal progress has been achieved in demonstrating the feasibility of BESs in scaled-up applications.This lack of scaled-up demonstration could be ascribed to the absence of suitable electrode modules(EMs)engineered for large-scale application.In this study,we report a scalable composite-engineered EM(total volume of 1 m^(3)),fabricated using graphite-coated stainless steel and carbon felt,that allows integrating BESs into mainstream wastewater treatment technologies.The cost-effectiveness and easy scalability of this EM provides a viable and clear path to facilitate the transition between the success of the lab studies and applications of BESs to solve multiple pressing environmental issues at full-scale.展开更多
Catalytic potential of carbon nanomaterials in peroxydisulfate(PDS)advanced oxidation systems for degradation of antibiotics remains poorly understood.This study revealed ordered mesoporous carbon(type CMK)acted as a ...Catalytic potential of carbon nanomaterials in peroxydisulfate(PDS)advanced oxidation systems for degradation of antibiotics remains poorly understood.This study revealed ordered mesoporous carbon(type CMK)acted as a superior catalyst for heterogeneous degradation of sulfadiazine(SDZ)in PDS sys-tem,with a first-order reaction kinetic constant(k)and total organic carbon(TOC)mineralization efficiency of 0.06 min^(–1) and 59.67%±3.4%within 60min,respectively.CMK catalyzed PDS system exhibited high degradation efficiencies of five other sulfonamides and three other types of antibiotics,verifying the broad-degradation capacity of antibiotics.Under neutral pH conditions,the optimal catalytic parameters were an initial SDZ concentration of 44.0mg/L,CMK dosage of 0.07g/L,and PDS dosage of 5.44mmol/L,respectively.X-ray photoelectron spectroscopy and Raman spectrum analysis confirmed that the defect structure at edge of CMK and oxygen-containing functional groups on surface of CMK were major active sites,contributing to the high catalytic activity.Free radical quenching analysis revealed that both SO_(4)•−and•OH were generated and participated in catalytic reaction.In addition,direct electron transfer by CMK to activate PDS also occurred,further promoting catalytic performance.Configuration of SDZ molecule was optimized using density functional theory,and the possible reaction sites in SDZ molecule were calculated using Fukui function.Combining ultra-high-performance liquid chromatography(UPLC)–mass spectrometry(MS)/MS analysis,three potential degradation pathways were proposed,including the direct removal of SO_(2)molecules,the 14S-17N fracture,and the 19C-20N and 19C-27N cleavage of the SDZ molecule.The study demonstrated that ordered mesoporous carbon could work as a feasible catalytic material for PDS advanced oxidation during removal of antibiotics from wastewater.展开更多
In this study, a novel scaled-up hybrid acidogenic bioreactor(HAB) was designed and adopted to evaluate the performance of azo dye(acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogeni...In this study, a novel scaled-up hybrid acidogenic bioreactor(HAB) was designed and adopted to evaluate the performance of azo dye(acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time(HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD(chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis(AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3% ± 2.5%, 86.2% ± 3.8% and 93.5% ± 1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS(61.1% ± 4.7%,75.4% ± 5.0% and 82.1% ± 2.1%, respectively). Moreover, larger TCV/TV(total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2% ± 3.7% and 28.30 ± 1.48 mA,respectively. They were significantly increased to 62.1% ± 2.0% and 34.55 ± 0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.展开更多
Traditional bioelectrochemical systems(BESs)coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen.In this study,we proposed a no...Traditional bioelectrochemical systems(BESs)coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen.In this study,we proposed a novel strategy to efficiently transport the oxidizing equivalent provided at the stripping unit to the cathode by introducing a highly soluble electron mediator(EM)into the catholyte.To validate this strategy,we developed a new kind of iron complex system(tartrate-EDTA-Fe)as the EM.EDTA-Fe contributed to the redox property with a midpoint potential of0.075 V(vs.standard hydrogen electrode,SHE)at pH 10,whereas tartrate acted as a stabilizer to avoid iron precipitation under alkaline conditions.At a ratio of the catholyte recirculation rate to the anolyte flow rate(RC-A)of 12,the NH4 t-N recovery rate in the system with 50mM tartrate-EDTA-Fe complex reached 6.9±0.2 g Nm^(-2) d^(-1),approximately 3.8 times higher than that in the non-EM control.With the help of the complex,our system showed an NH4 t-N recovery performance comparable to that previously reported but with an extremely low RC-A(0.5 vs.288).The strategy proposed here may guide the future of ammonia recovery BES scale-up because the introduction of an EM allows aeration to be performed only at the stripping unit instead of at every cathode,which is beneficial for the system design due to its simplicity and reliability.展开更多
基金the financial support by the National Natural Science Foundation of China(52230004 and 52293445)the Key Research and Development Project of Shandong Province(2020CXGC011202-005)the Shenzhen Science and Technology Program(KCXFZ20211020163404007 and KQTD20190929172630447).
文摘The potential for reducing greenhouse gas(GHG)emissions and energy consumption in wastewater treatment can be realized through intelligent control,with machine learning(ML)and multimodality emerging as a promising solution.Here,we introduce an ML technique based on multimodal strategies,focusing specifically on intelligent aeration control in wastewater treatment plants(WWTPs).The generalization of the multimodal strategy is demonstrated on eight ML models.The results demonstrate that this multimodal strategy significantly enhances model indicators for ML in environmental science and the efficiency of aeration control,exhibiting exceptional performance and interpretability.Integrating random forest with visual models achieves the highest accuracy in forecasting aeration quantity in multimodal models,with a mean absolute percentage error of 4.4%and a coefficient of determination of 0.948.Practical testing in a full-scale plant reveals that the multimodal model can reduce operation costs by 19.8%compared to traditional fuzzy control methods.The potential application of these strategies in critical water science domains is discussed.To foster accessibility and promote widespread adoption,the multimodal ML models are freely available on GitHub,thereby eliminating technical barriers and encouraging the application of artificial intelligence in urban wastewater treatment.
基金supported by the National Natural Science Foundation of China(52321005,52293443,and 52230004)the Shenzhen Science and Technology Program(KQTD20190929172630447)+1 种基金the Shenzhen Key Research Project(GXWD20220817145054002)the Talent Recruitment Project of Guandong(2021QN020106).
文摘The digital twins concept enhances modeling and simulation through the integration of real-time data and feedback.This review elucidates the foundational elements of digital twins,covering their concept,entities,domains,and key technologies.More specifically,we investigate the transformative potential of digital twins for the wastewater treatment engineering sector.Our discussion highlights the application of digital twins to wastewater treatment plants(WWTPs)and sewage networks,hardware(i.e.,facilities and pipes,sensors for water quality and activated sludge,hydrodynamics,and power consumption),and software(i.e.,knowledge-based and data-driven models,mechanistic models,hybrid twins,control methods,and the Internet of Things).Furthermore,two cases are provided,followed by an assessment of current challenges in and perspectives on the application of digital twins in WWTPs.This review serves as an essential primer for wastewater engineers navigating the digital paradigm shift.
基金supported by the National Natural Science Foundation of China (No. 52170164)the Open Project of Key Laboratory of Environmental Biotechnology,CAS (No. kf2018001)the Scientific Research Foundation for Returned Scholars at the University of South China (No. 2018XQD25)
文摘Mixed bacteria were enriched from heavy metals mine soil for cadmium(Cd(Ⅱ))-containing wastewater treatment. Batch adsorption experiment results showed that the optimal pH, temperature, initial Cd(Ⅱ) concentration, and biomass dosage were 6.0, 30 ℃, 20 mg/L, and 1 g/L, respectively. Living biomass exhibited better Cd(Ⅱ) removal efficiency(91.97%) than autoclaved biomass(79.54%) under optimal conditions. The isotherms and kinetics of living biomass conformed to the Langmuir isotherm model and pseudo-first-order kinetic model, respectively. FTIR results implied that amine groups, hydroxyl groups and phosphoric acid play an important role in the Cd(Ⅱ) adsorption process, while XRD results showed that crystalline Cd(OH)and CdO were obtained. After Cd(Ⅱ)-containing wastewater treatment exposure, the dominant bacteria genera included Comamonas(39.94%), unclassified_f__Enterobacteriaceae(34.96%), Ochrobactrum(14.07%), Alcaligenes(4.84%), Bordetella(2.07%), Serratia(1.04%), and Bacillus(1.01%). Function prediction showed that the abundance of metabolic genes changed significantly. This study proposes the potential application of mixed bacteria for Cd(Ⅱ)-containing wastewater treatment.
基金supported by the National Natural Science Foundation of China(No.52000090 and No.52370171)the National Science Foundation of China(No.52321005)+2 种基金the China Postdoctoral Science Foundation(No.2021M701511)the Shenzhen Overseas High-level Talents Research Startup Program from Harbin Institute of Technology(Shenzhen)the Natural Science Foundation of Guangdong Province for Distinguished Young Scientists(No.2021B1515020084).
文摘Energy recovery from low-strength wastewater through anaerobic methanogenesis is constrained by limited substrate availability.The development of efficient methanogenic communities is critical but challenging.Here we develop a strategy to acclimate methanogenic communities using conductive carrier(CC),electrical stress(ES),and Acid Orange 7(AO7)in a modified biofilter.The synergistic integration of CC,ES,and AO7 precipitated a remarkable 72-fold surge in methane production rate compared to the baseline.This increase was attributed to an altered methanogenic community function,independent of the continuous presence of AO7 and ES.AO7 acted as an external electron acceptor,accelerating acetogenesis from fermentation intermediates,restructuring the bacterial community,and enriching electroactive bacteria(EAB).Meanwhile,CC and ES orchestrated the assembly of the archaeal community and promoted electrotrophic methanogens,enhancing acetotrophic methanogenesis electron flow via a mechanism distinct from direct electrochemical interactions.The collective application of CC,ES,and AO7 effectively mitigated electron flow impediments in low-strength wastewater methanogenesis,achieving an additional 34%electron recovery from the substrate.This study proposes a new method of amending anaerobic digestion systems with conductive materials to advance wastewater treatment,sustainability,and energy self-sufficiency.
基金support of the National Key Research and Development Program of China(Grant No.2019YFC1803804-02)the Open Project of the Key Laboratory of Environmental Biotechnology,CAS(Grant No.kf2021008).
文摘Remediating soil contaminated with polycyclic aromatic hydrocarbons(PAHs)presents a significant environmental challenge due to their toxic and carcinogenic properties.Traditional PAHs remediation methodsdchemical,thermal,and bioremediationdalong with conventional soil-washing agents like surfactants and cyclodextrins face challenges of cost,ecological harm,and inefficiency.Here we show an effective and environmentally friendly calixarene derivative for PAHs removal through soil washing.Thiacalix[4]arene tetrasulfonate(TCAS)has a unique molecular structure of a sulfonate group and a sulfur atom,which enhances its solubility and facilitates selective binding with PAHs.It forms host-guest complexes with PAHs through p-p stacking,OH-p interactions,hydrogen bonding,van der Waals forces,and electrostatic interactions.These interactions enable partial encapsulation of PAH molecules,aiding their desorption from the soil matrix.Our results show that a 0.7%solution of TCAS can extract approximately 50%of PAHs from contaminated soil while preserving soil nutrients and minimizing adverse environmental effects.This research unveils the pioneering application of TCAS in removing PAHs from contaminated soil,marking a transformative advancement in resource-efficient and sustainable soil remediation strategies.
基金supported by the National Natural Science Foundation of China(No.52070060 and No.52230004)Shenzhen Overseas High-level Talents Research Startup Program(No.20200518750C)+2 种基金Shenzhen Science and Technology Program(Grant No.KQTD20190929172630447)State Key Laboratory of Urban Water Resource and Environment(Harbin Institute of Technology)(No.2021TS29)Open Project of Key Laboratory of Environmental Biotechnology,CAS(Grant No KF2021006).
文摘As one of the typical emerging contaminants,microplastics exist widely in the environment because of their small size and recalcitrance,which has caused various ecological problems.This paper summarizes current adsorption and removal technologies of microplastics in typical aquatic environments,including natural freshwater,marine,drinking water treatment plants(DWTPs),and wastewater treatment plants(WWTPs),and includes abiotic and biotic degradation technologies as one of the removal technologies.Recently,numerous studies have shown that enrichment technologies have been widely used to remove microplastics in natural freshwater environments,DWTPs,and WWTPs.Efficient removal of microplastics via WWTPs is critical to reduce the release to the natural environment as a key connection point to prevent the transfer of microplastics from society to natural water systems.Photocatalytic technology has outstanding pre-degradation effects on microplastics,and the isolated microbial strains or enriched communities can degrade up to 50%or more of pre-processed microplastics.Thus,more research focusing on microplastic degradation could be carried out by combining physical and chemical pretreatment with subsequent microbial biodegradation.In addition,the current recovery technologies of microplastics are introduced in this review.This is incredibly challenging because of the small size and dispersibility of microplastics,and the related technologies still need further development.This paper will provide theoretical support and advice for preventing and controlling the ecological risks mediated by microplastics in the aquatic environment and share recommendations for future research on the removal and recovery of microplastics in various aquatic environments,including natural aquatic environments,DWTPs,and WWTPs.
基金supported by the NSFC-JSPS joint research program(No.51961145202)the Natural Science Foundation of Heilongjiang Province,China(No.C2018035)。
文摘Pd modified electrodes possess problems such as easy agglomeration and low electrolytic ability,and the use of manganese dioxide(MnO_(2)) to facilitate Pd reduction of organic pollutants is just started.However,there is still a limited understanding of how to match the Pd load and MnO_(2) to realize optimal dechlorination efficiency at minimum cost.Here,a Pd/MnO_(2)/Ni foam cathode was successfully fabricated and applied for the efficient electrochemical dechlorination of 2,4,6-trichlorophenol(2,4,6-TCP).The optimal electrocatalytic hydrodechlorination(ECH)performance with 2,4,6-TCP dechlorination efficiency(92.58%in 180 min)was obtained when the concentration of PdCl_(2) precipitation was 1 mmol/L,the deposition time of MnO_(2) was 300 s and cathode potential was-0.8 V.Performance influenced by the exogenous factors(e.g.,initial pH and coexisted ions)were further investigated.It was found that the neutral pH was the most favorable for ECH and a reduction in dechlorination efficiency(6%~47.6%)was observed in presence of 5 mmol/L of NO_(2)^(-),NO_(3)^(-),S^(2-)or SO_(3)^(2-).Cyclic voltammetry(CV)and quenching experiments verified the existence of three hydrogen species on Pd surface,including adsorbed atomic hydrogen(H^(*)_(ads)),absorbed atomic hydrogen(H^(*)_(abs)),and molecular hydrogen(H_(2)).And the introduction of MnO_(2)promoted the generation of atomic H^(*).Only adsorbed atomic hydrogen(H^(*)_(ads)) was confirmed that it truly facilitated the ECH process.Besides H^(*)_(ads) induced reduction,the direct reduction by cathode electrons also participated in the 2,4,6-TCP dechlorination process.Pd/MnO_(2)/Ni foam cathode shows excellent dechlorination performance,fine stability and recyclable potential,which provides strategies for the effective degradation of persistent halogenated organic pollutants in groundwater.
基金financially supported by the NSFC-EU Environmental Biotechnology joint program(No.31861133001).
文摘Bioelectrochemical systems(BESs)have been studied extensively during the past decades owing primarily to their versatility and potential in addressing the water-energy-resource nexus.In stark contrast to the significant advancements that have been made in developing innovative processes for pollution control and bioresource/bioenergy recovery,minimal progress has been achieved in demonstrating the feasibility of BESs in scaled-up applications.This lack of scaled-up demonstration could be ascribed to the absence of suitable electrode modules(EMs)engineered for large-scale application.In this study,we report a scalable composite-engineered EM(total volume of 1 m^(3)),fabricated using graphite-coated stainless steel and carbon felt,that allows integrating BESs into mainstream wastewater treatment technologies.The cost-effectiveness and easy scalability of this EM provides a viable and clear path to facilitate the transition between the success of the lab studies and applications of BESs to solve multiple pressing environmental issues at full-scale.
基金supported by the NSFC-JSPS joint research pro-gram(No.51961145202)the Natural Science Foundation of Heilongjiang Province,China(No.C2018035).
文摘Catalytic potential of carbon nanomaterials in peroxydisulfate(PDS)advanced oxidation systems for degradation of antibiotics remains poorly understood.This study revealed ordered mesoporous carbon(type CMK)acted as a superior catalyst for heterogeneous degradation of sulfadiazine(SDZ)in PDS sys-tem,with a first-order reaction kinetic constant(k)and total organic carbon(TOC)mineralization efficiency of 0.06 min^(–1) and 59.67%±3.4%within 60min,respectively.CMK catalyzed PDS system exhibited high degradation efficiencies of five other sulfonamides and three other types of antibiotics,verifying the broad-degradation capacity of antibiotics.Under neutral pH conditions,the optimal catalytic parameters were an initial SDZ concentration of 44.0mg/L,CMK dosage of 0.07g/L,and PDS dosage of 5.44mmol/L,respectively.X-ray photoelectron spectroscopy and Raman spectrum analysis confirmed that the defect structure at edge of CMK and oxygen-containing functional groups on surface of CMK were major active sites,contributing to the high catalytic activity.Free radical quenching analysis revealed that both SO_(4)•−and•OH were generated and participated in catalytic reaction.In addition,direct electron transfer by CMK to activate PDS also occurred,further promoting catalytic performance.Configuration of SDZ molecule was optimized using density functional theory,and the possible reaction sites in SDZ molecule were calculated using Fukui function.Combining ultra-high-performance liquid chromatography(UPLC)–mass spectrometry(MS)/MS analysis,three potential degradation pathways were proposed,including the direct removal of SO_(2)molecules,the 14S-17N fracture,and the 19C-20N and 19C-27N cleavage of the SDZ molecule.The study demonstrated that ordered mesoporous carbon could work as a feasible catalytic material for PDS advanced oxidation during removal of antibiotics from wastewater.
基金financially supported by the Ministry of Environmental Protection of the People's Republic of China (Major Science and Technology Program for Water Pollution Control and Treatment) (No. 2014ZX07204-005)the National Natural Science Foundation of China (Nos. 51222812, 31370157, 21407164, 51508551)+2 种基金the China Postdoctoral Science Foundation (No. 2015M580140)the National Science Foundation for Distinguished Young Scholars (No. 51225802)Hundred Talents Program of the Chinese Academy of Sciences (No. 29BR2013001)
文摘In this study, a novel scaled-up hybrid acidogenic bioreactor(HAB) was designed and adopted to evaluate the performance of azo dye(acid red G, ARG) containing wastewater treatment. Principally, HAB is an acidogenic bioreactor coupled with a biocatalyzed electrolysis module. The effects of hydraulic retention time(HRT) and ARG loading rate on the performance of HAB were investigated. In addition, the influent was switched from synthetic wastewater to domestic wastewater to examine the key parameters for the application of HAB. The results showed that the introduction of the biocatalyzed electrolysis module could enhance anoxic decolorization and COD(chemical oxygen demand) removal. The combined process of HAB-CASS presented superior performance compared to a control system without biocatalyzed electrolysis(AB-CASS). When the influent was switched to domestic wastewater, with an environment having more balanced nutrients and diverse organic matters, the ARG, COD and nitrogen removal efficiencies of HAB-CASS were further improved, reaching 73.3% ± 2.5%, 86.2% ± 3.8% and 93.5% ± 1.6% at HRT of 6 hr, respectively, which were much higher than those of AB-CASS(61.1% ± 4.7%,75.4% ± 5.0% and 82.1% ± 2.1%, respectively). Moreover, larger TCV/TV(total cathode volume/total volume) for HAB led to higher current and ARG removal. The ARG removal efficiency and current at TCV/TV of 0.15 were 39.2% ± 3.7% and 28.30 ± 1.48 mA,respectively. They were significantly increased to 62.1% ± 2.0% and 34.55 ± 0.83 mA at TCV/TV of 0.25. These results show that HAB system could be used to effectively treat real wastewater.
基金This work was supported by the NSFC-EU Environmental Biotechnology joint program(No.31861133001)Key Research and Development Project of Shandong Province(No.2020CXGC011202)+1 种基金Shenzhen Science and Technology Program(No.KQTD20190929172630447)China Postdoctoral Science Foundation(No.2020M680708).
文摘Traditional bioelectrochemical systems(BESs)coupled with stripping units for ammonia recovery suffer from an insufficient supply of electron acceptors due to the low solubility of oxygen.In this study,we proposed a novel strategy to efficiently transport the oxidizing equivalent provided at the stripping unit to the cathode by introducing a highly soluble electron mediator(EM)into the catholyte.To validate this strategy,we developed a new kind of iron complex system(tartrate-EDTA-Fe)as the EM.EDTA-Fe contributed to the redox property with a midpoint potential of0.075 V(vs.standard hydrogen electrode,SHE)at pH 10,whereas tartrate acted as a stabilizer to avoid iron precipitation under alkaline conditions.At a ratio of the catholyte recirculation rate to the anolyte flow rate(RC-A)of 12,the NH4 t-N recovery rate in the system with 50mM tartrate-EDTA-Fe complex reached 6.9±0.2 g Nm^(-2) d^(-1),approximately 3.8 times higher than that in the non-EM control.With the help of the complex,our system showed an NH4 t-N recovery performance comparable to that previously reported but with an extremely low RC-A(0.5 vs.288).The strategy proposed here may guide the future of ammonia recovery BES scale-up because the introduction of an EM allows aeration to be performed only at the stripping unit instead of at every cathode,which is beneficial for the system design due to its simplicity and reliability.