Chromium(Cr)is a common heavy metal that has severe impacts on the ecosystem and human health.Capacitive deionization(CDI)is an environment-friendly and energy-efficient electrochemical purification technology to remo...Chromium(Cr)is a common heavy metal that has severe impacts on the ecosystem and human health.Capacitive deionization(CDI)is an environment-friendly and energy-efficient electrochemical purification technology to remove Cr from polluted water.The performance of CDI systems relies primarily on the properties of electrodes.Carbon-nanotubes(CNTs)membranes are promising candidates in creating advanced CDI electrodes and processes.However,the low electrosorption capacity and high hydrophobicity of CNTs greatly impede their applications in water systems.In this study,we employ atomic layer deposition(ALD)to deposit TiO_(2) nanoparticulates on CNTs membranes for preparing electrodes with hydrophilicity.The TiO_(2)-deposited CNTs membranes display preferable electrosorption performance and reusability in CDI processes after only 20 ALD cycles deposition.The total Cr and Cr(VI)removal efficiencies are significantly improved to 92.1%and 93.3%,respectively.This work demonstrates that ALD is a highly controllable and simple method to produce advanced CDI electrodes,and broadens the application of metal oxide/carbon composites in the electrochemical processes.展开更多
Water and energy shortages came due to rapid population growth, living standards and rapid development in the agriculture and industrial sectors. Desalination tends to be one of the most promising water solutions;howe...Water and energy shortages came due to rapid population growth, living standards and rapid development in the agriculture and industrial sectors. Desalination tends to be one of the most promising water solutions;however, it is a process of intense energy. Membrane Capacitive Deionization (MCDI) has received considerable interest as a promising desalination technology, and MCDI research has increased significantly over the last 10 years. In addition, there are no guidelines for the design of Capacitive Deionization (CDI) implementation strategies for individual applications. This study, therefore;provides an alternative of CDI’s recent application developments, with emphasis placed on hybrid systems to address the technological needs of different relevant fields. The MCDI’s energy consumption is compared with the reverse osmosis literature data based on experimental data from laboratory-scale system. The study demonstrates that MCDI technology is a promising technology in the next few years with an extreme competition in water recovery, energy consumption and salt removal for reverse osmosis.展开更多
Membrane capacitive deionization(MCDI)is an efficient desalination technology for brine.Penicillin fermentation residue biochar(PFRB)possesses a hierarchical porous and O/N-doped structure which could serve as a high-...Membrane capacitive deionization(MCDI)is an efficient desalination technology for brine.Penicillin fermentation residue biochar(PFRB)possesses a hierarchical porous and O/N-doped structure which could serve as a high-capacity desalination electrode in the MCDI system.Under optimal conditions(electrode weight,voltage,and concentration)and a carbonization temperature of 700℃,the maximum salt adsorption capacity of the electrode can reach 26.4 mg/g,which is higher than that of most carbon electrodes.Furthermore,the electrochemical properties of the PFRB electrode were characterized through cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS)with a maximum specific capacitance of 212.18 F/g.Finally,biotoxicity tests have showed that PFRB was non-biotoxin against luminescent bacteria and the MCDI system with the PFRB electrode remained stable even after 27 adsorption–desorption cycles.This study provides a novel way to recycle penicillin residue and an electrode that can achieve excellent desalination.展开更多
The adsorption and desorption behavior of Cr(Ⅵ) in membrane capacitive deionization(MCDI) was investigated systematically in the presence of bovine serum albumin(BSA) and KCl with different concentrations, respective...The adsorption and desorption behavior of Cr(Ⅵ) in membrane capacitive deionization(MCDI) was investigated systematically in the presence of bovine serum albumin(BSA) and KCl with different concentrations, respectively. Results revealed that Cr(Ⅵ) absorption was enhanced and the adsorption amount for Cr(Ⅵ) increased from 155.7 to 190.8 mg/g when KCl concentration increased from 100 to 200 mg/L in the adsorption process, which was attributed to the stronger driving force. However, the adsorption amount sharply decreased to 90.2 mg/g when KCl concentration reached up to 1000 mg/L suggesting the negative effect for Cr(Ⅵ) removal that high KCl concentration had. As for the effect of BSA on ion adsorption, the amount for Cr(Ⅵ) significantly declined to 78.3 mg/g and p H was found to be an important factor contributing to this significant reduction. Then, the desorption performance was also conducted and it was obtained that the presence of KCl had negligible effect on Cr(Ⅵ) desorption, while promoted by the addition of BSA. The incomplete desorption was obtained and the residual chromium ions onto the electrode after desorption was detected via energy-dispersive X-ray spectroscopy(EDS). Based on above analysis, the enhanced removal mechanism for Cr(Ⅵ) in MCDI was found to be consisted of ion adsorption onto electrode surface, the redox reaction of Cr(Ⅵ) into Cr(III)and precipitation, which was demonstrated by X-ray photoelectron spectroscopy(XPS) and scanning electron microscope(SEM).展开更多
The practical application of the capacitive deionization(CDI)enhanced ultrafiltration(CUF)technology is hampered due to low performance of electrodes.The current study demonstrated a novel super-aligned carbon nanotub...The practical application of the capacitive deionization(CDI)enhanced ultrafiltration(CUF)technology is hampered due to low performance of electrodes.The current study demonstrated a novel super-aligned carbon nanotube(SACNT)/activated carbon(AC)composite electrode,which was prepared through coating AC on a cross-stacked SACNT film.The desalination capability and water purification performance of the prepared electrode were systematically investigated at different applied voltages(0.8-1.2 V)with a CDI system and a CUF system,respectively.In the CDI tests,as compared with 5ie control AC electrode,the SACNT/AC electrode achieved an approximately 100%increase in both maximum salt adsorption capacity and average salt adsorption rate under all the applied voltage conditions,demonstrating a superior desalination capability.Meanwhile,a conspicuous increase by an average of-26%in charge efficiency was also achieved at all the voltages.In the CUF tests,as compared with the control run at 0 V,the treatment runs at 0.8,1.0,and 1.2 V achieved a 2.40-fold,2.08-fold,and 2.43-fold reduction in membrane fouling(calculated according to the final transmembrane pressure(TMP)data at the end of every purification stage),respectively.The average TMP increasing rates at 0.8,1.0,and 1.2 V were also roughly two times smaller than that at 0 V,indicating a dramatical reduction of membrane fouling.The SACNT/AC electrode also maintained its superior desalination capability in the CUF process,resulting in an overall improved water purification efficiency.展开更多
Membrane capacitive deionization(MCDI)is a cost-effective desalination technique known for its low energy consumption.The performance of MCDI cells relies on the properties of electrode materials.Activated carbon is t...Membrane capacitive deionization(MCDI)is a cost-effective desalination technique known for its low energy consumption.The performance of MCDI cells relies on the properties of electrode materials.Activated carbon is the most widely used electrode material.However,the capacitive carbon available on the market is often expensive.Here,we developed hierarchically porous biochar by combining carbonization and activation processes,using easily acquired aerobic granular sludge(AGS)from biological sewage treatment plants as a precursor.The biochar had a specific surface area of 1822.07 m^(2)g^(-1),with a micropore area ratio of 58.65%and a micropore volume of 0.576 cm3 g^(-1).The MCDI cell employing the biochar as electrodes demonstrated a specific adsorption capacity of 34.35 mg g^(-1),comparable to commercially available activated carbon electrodes.Our study presents a green and sustainable approach for preparing highly efficient,hierarchically porous biochar from AGS,offering great potential for enhanced performance in MCDI applications.展开更多
以石墨带为电极材料,研究了工作电压、进料流量和隔网厚度等工艺条件对电容法脱盐(CDI)性能的影响。结果表明:工作电压由0.8 V增加至2.0 V时,脱盐率和质量比吸附量先增加然后趋于稳定;进料流量由48 m L/min增加至238 m L/min时,脱盐率...以石墨带为电极材料,研究了工作电压、进料流量和隔网厚度等工艺条件对电容法脱盐(CDI)性能的影响。结果表明:工作电压由0.8 V增加至2.0 V时,脱盐率和质量比吸附量先增加然后趋于稳定;进料流量由48 m L/min增加至238 m L/min时,脱盐率和质量比吸附量先增加后减小;隔网厚度由0增加至1.8 mm时,质量比吸附量先减小后增加。在电压1.6 V、进料流量142m L/min、隔网厚度1.8 mm时,CDI脱盐性能较好。在上述相同的工艺条件下,对CDI与膜电容法脱盐(MCDI)进行了对比研究。结果表明:在第1个循环的吸附阶段,MCDI脱盐率和电流效率分别比CDI增加了31.68%和36.16%;16 h循环吸脱附实验后,MCDI再生率为99.01%。表明MCDI比CDI具有更好的脱盐性能和再生性能。展开更多
基金Financial supports from the Jiangsu Natural Science Foundation(BK20190677)National Natural Science Foundation of China(21908096)+2 种基金Scientific Research Foundation of Chuzhou University(2020qd06)support from the Program of Excellent Innovation Teams of Jiangsu Higher Education Institutionsthe Project of Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Chromium(Cr)is a common heavy metal that has severe impacts on the ecosystem and human health.Capacitive deionization(CDI)is an environment-friendly and energy-efficient electrochemical purification technology to remove Cr from polluted water.The performance of CDI systems relies primarily on the properties of electrodes.Carbon-nanotubes(CNTs)membranes are promising candidates in creating advanced CDI electrodes and processes.However,the low electrosorption capacity and high hydrophobicity of CNTs greatly impede their applications in water systems.In this study,we employ atomic layer deposition(ALD)to deposit TiO_(2) nanoparticulates on CNTs membranes for preparing electrodes with hydrophilicity.The TiO_(2)-deposited CNTs membranes display preferable electrosorption performance and reusability in CDI processes after only 20 ALD cycles deposition.The total Cr and Cr(VI)removal efficiencies are significantly improved to 92.1%and 93.3%,respectively.This work demonstrates that ALD is a highly controllable and simple method to produce advanced CDI electrodes,and broadens the application of metal oxide/carbon composites in the electrochemical processes.
文摘Water and energy shortages came due to rapid population growth, living standards and rapid development in the agriculture and industrial sectors. Desalination tends to be one of the most promising water solutions;however, it is a process of intense energy. Membrane Capacitive Deionization (MCDI) has received considerable interest as a promising desalination technology, and MCDI research has increased significantly over the last 10 years. In addition, there are no guidelines for the design of Capacitive Deionization (CDI) implementation strategies for individual applications. This study, therefore;provides an alternative of CDI’s recent application developments, with emphasis placed on hybrid systems to address the technological needs of different relevant fields. The MCDI’s energy consumption is compared with the reverse osmosis literature data based on experimental data from laboratory-scale system. The study demonstrates that MCDI technology is a promising technology in the next few years with an extreme competition in water recovery, energy consumption and salt removal for reverse osmosis.
基金This work was supported by the Natural Science Foundation of Hebei Province(China)(Nos.B2021208035,B2020208064,and E2020208054).
文摘Membrane capacitive deionization(MCDI)is an efficient desalination technology for brine.Penicillin fermentation residue biochar(PFRB)possesses a hierarchical porous and O/N-doped structure which could serve as a high-capacity desalination electrode in the MCDI system.Under optimal conditions(electrode weight,voltage,and concentration)and a carbonization temperature of 700℃,the maximum salt adsorption capacity of the electrode can reach 26.4 mg/g,which is higher than that of most carbon electrodes.Furthermore,the electrochemical properties of the PFRB electrode were characterized through cyclic voltammetry(CV)and electrochemical impedance spectroscopy(EIS)with a maximum specific capacitance of 212.18 F/g.Finally,biotoxicity tests have showed that PFRB was non-biotoxin against luminescent bacteria and the MCDI system with the PFRB electrode remained stable even after 27 adsorption–desorption cycles.This study provides a novel way to recycle penicillin residue and an electrode that can achieve excellent desalination.
基金financially supported by the National Natural Science Fund of China (No. 51508153)the Natural Science Fund of Jiangsu (No. BK20150813)+1 种基金the Fundamental Research Funds for the Central UniversitiesA Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘The adsorption and desorption behavior of Cr(Ⅵ) in membrane capacitive deionization(MCDI) was investigated systematically in the presence of bovine serum albumin(BSA) and KCl with different concentrations, respectively. Results revealed that Cr(Ⅵ) absorption was enhanced and the adsorption amount for Cr(Ⅵ) increased from 155.7 to 190.8 mg/g when KCl concentration increased from 100 to 200 mg/L in the adsorption process, which was attributed to the stronger driving force. However, the adsorption amount sharply decreased to 90.2 mg/g when KCl concentration reached up to 1000 mg/L suggesting the negative effect for Cr(Ⅵ) removal that high KCl concentration had. As for the effect of BSA on ion adsorption, the amount for Cr(Ⅵ) significantly declined to 78.3 mg/g and p H was found to be an important factor contributing to this significant reduction. Then, the desorption performance was also conducted and it was obtained that the presence of KCl had negligible effect on Cr(Ⅵ) desorption, while promoted by the addition of BSA. The incomplete desorption was obtained and the residual chromium ions onto the electrode after desorption was detected via energy-dispersive X-ray spectroscopy(EDS). Based on above analysis, the enhanced removal mechanism for Cr(Ⅵ) in MCDI was found to be consisted of ion adsorption onto electrode surface, the redox reaction of Cr(Ⅵ) into Cr(III)and precipitation, which was demonstrated by X-ray photoelectron spectroscopy(XPS) and scanning electron microscope(SEM).
基金The authors gratefully acknowledge the financial support from the Beijing Municipal Natural Science Foundation(Nos.8192030 and L182026)Fundamental Research Funds for the Central Universities(No.2016ZCQ03)National Natural Science Foundation of China(Nos.51608038 and 21975140).
文摘The practical application of the capacitive deionization(CDI)enhanced ultrafiltration(CUF)technology is hampered due to low performance of electrodes.The current study demonstrated a novel super-aligned carbon nanotube(SACNT)/activated carbon(AC)composite electrode,which was prepared through coating AC on a cross-stacked SACNT film.The desalination capability and water purification performance of the prepared electrode were systematically investigated at different applied voltages(0.8-1.2 V)with a CDI system and a CUF system,respectively.In the CDI tests,as compared with 5ie control AC electrode,the SACNT/AC electrode achieved an approximately 100%increase in both maximum salt adsorption capacity and average salt adsorption rate under all the applied voltage conditions,demonstrating a superior desalination capability.Meanwhile,a conspicuous increase by an average of-26%in charge efficiency was also achieved at all the voltages.In the CUF tests,as compared with the control run at 0 V,the treatment runs at 0.8,1.0,and 1.2 V achieved a 2.40-fold,2.08-fold,and 2.43-fold reduction in membrane fouling(calculated according to the final transmembrane pressure(TMP)data at the end of every purification stage),respectively.The average TMP increasing rates at 0.8,1.0,and 1.2 V were also roughly two times smaller than that at 0 V,indicating a dramatical reduction of membrane fouling.The SACNT/AC electrode also maintained its superior desalination capability in the CUF process,resulting in an overall improved water purification efficiency.
基金financial support from the National Natural Science Foundation of China(Grant No.52160003 and 52264039)the State Key Laboratory of Urban Water Resource and Environment at Harbin Institute of Technology(2020DX05)+2 种基金Natural Science Foundation of Gansu Province(Grant No.20JR5RA436)the National Key Research&Development Program of China(2022YFC3203101)Foster Foundation of International Research Base of Seismic Mitigation and Isolation of Gansu Province(No.GII2022-P02).
文摘Membrane capacitive deionization(MCDI)is a cost-effective desalination technique known for its low energy consumption.The performance of MCDI cells relies on the properties of electrode materials.Activated carbon is the most widely used electrode material.However,the capacitive carbon available on the market is often expensive.Here,we developed hierarchically porous biochar by combining carbonization and activation processes,using easily acquired aerobic granular sludge(AGS)from biological sewage treatment plants as a precursor.The biochar had a specific surface area of 1822.07 m^(2)g^(-1),with a micropore area ratio of 58.65%and a micropore volume of 0.576 cm3 g^(-1).The MCDI cell employing the biochar as electrodes demonstrated a specific adsorption capacity of 34.35 mg g^(-1),comparable to commercially available activated carbon electrodes.Our study presents a green and sustainable approach for preparing highly efficient,hierarchically porous biochar from AGS,offering great potential for enhanced performance in MCDI applications.
