CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xun Liu,Danyal Rehman,Yufei Shu,Bei Liu,Li Wang,Li Li,Mengxia Wang,Kunkun Wang,Qi Han,Linlin Zang,John H. Lienhard,Zhongying Wang
Selective capacitive deionization (SCDI) is a promising process for preferentially removing specific ions from waters with complex compositions. The selectivity towards certain species in CDI is most frequently achieved through novel electrode materials with high affinities towards targeted species. In this study, we investigate the selective removal of fluoride ions from groundwater containing concentrated co-existing chloride ions. A carbon nanotube-CeO 2 (CNT-CeO 2 ) electrode is employed for the electro-sorption of fluoride ions. Our findings are compelling: when processing a mixed F − /Cl − solution comprising 10 mg/L F − and 100 mg/L Cl − , the CNT-CeO 2 electrode is seen to reduce the concentration of F − ions to 1.5 mg/L in just 150 min, amounting to an 85 % F − removal efficiency, while the Cl − removal efficiency remains below 2 %. Importantly, this translates to a F − /Cl − separation factor of up to 4.16 when using the CeO 2 -based electrodes, which is 40 times higher than that achieved with conventional activated carbon (AC) electrodes. Furthermore, the energy consumption for treating actual groundwater using scaled-up equipment is impressively low at approximately 0.2 kWh/m 3 . The high affinity of CNT-CeO 2 towards fluoride is attributed to the intercalation Faraday capacitance initiated by the reaction between F − with CeO 2 , as verified by the electrochemical quartz crystal microbalance (EQCM). Moreover, EQCM results show a substantial increase in both mass and current as the potential increased beyond 0.8 V vs Ag/AgCl, implying that the current surge is not a result of water splitting but rather the adsorption of F − onto the CNT-CeO 2 electrode. The addition of CNTs substantially increases the conductivity of CeO 2 electrodes and restricts the aggregation of CeO 2 , thereby accelerating ion diffusion and promoting selective adsorption characteristics. Importantly, our electro-driven approach demonstrates excellent adsorption–desorption over 20 cycles. This comprehensive study advances the technological development of selective CDI, while providing new insights for fluoride removal in groundwater.
研究领域:
环境工程
·
水处理
·
电化学
·
材料科学
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2019
·
IF 7.913
Tianyu Wang,Changyong Zhang,Langming Bai,Binghan Xie,Zhendong Gan,Jiajian Xing,Guibai Li,Heng Liang
This study investigated the fouling and scaling behaviors in a capacitive deionization (CDI) system in the presence of iron and natural organic matter (NOM). It was found that the salt adsorption capacity (SAC) significantly decreased when treating Fe-containing brackish water, with higher Fe concentrations leading to severer SAC reduction. Raman spectroscopy , X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis demonstrated that Fe 2 O 3 appeared to be the predominant foulant attached on the electrode surface, which was difficult to be removed via backwashing, indicating the irreversible property of the foulant. Further characterizations (e.g., N 2 sorption-desorption isotherms, electrochemical impedance spectroscopy and cyclic voltammetry) revealed that the CDI electrodes suffered from obvious deterioration such as specific surface area loss, resistance increase and capacitance decline with the occurrence of Fe scaling. While the presence of NOM alleviated the Fe scaling through NOM-Fe complexing effects, NOM itself was found to have negative impacts on CDI desalination performance due to their strong interactions with the carbon electrodes.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Environmental Science-Water Research & Technology
·
2019
·Vol. 6
·期 2
·373-382
·
IF 4.195
Junjun Chang,Feng Duan,Chunlei Su,Yuping Li,Hongbin Cao
Non-carbon materials in capacitive deionization (CDI) can help to enhance the capacity of removed ions. Here, we report for the first time the removal of chloride ions (Cl−) with a bismuth (Bi) anode when coupled with an activated carbon (AC) cathode in CDI. The effects of carbon black in the Bi electrode, applied voltage, electrode mass loading and initial concentration on Cl− removal are investigated. Moreover, its cycle performance is also tested. Results show that addition of carbon black to a Bi electrode (Bi@CB) significantly improves Cl− removal. The declining trend of Cl− concentration and appearance of peaks assigned to products of bismuth oxychloride (BiOCl) in XRD patterns confirm Cl− storage by the Bi electrode, which is enhanced with an increase in voltage. When coupled with AC in a fixed mass, increasing the Bi mass does not contribute to more Cl− removal. Although the cycle performance is not excellent (the attenuation rate is 74% after 10 cycles), its chloride removal capacity is ∼2–3 times the value of AC (e.g. 0.95 vs. 0.32 mmol gBi−1 at 1.2 V in 500 mg L−1 NaCl solution). Besides, the Bi–AC electrode pair in CDI is more suitable to remove Cl− from a solution with a Cl− concentration of below 600 mg L−1.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
DESALINATION
·
2023
·
IF 9.9
Jiazhou He,Tsai-Hsuan Chen,Kui Yang,Liang Luo,Chia-Hung Hou,Jinxing Ma
Brackish water desalination has become a major opportunity to fulfill the rising clean water needs globally. Capacitive deionization (CDI) is an attractive electrochemical separation technology to treat water salinity , and the innovative discharge operation, termed stop-flow (SF) discharge, has demonstrated high efficiency to minimize the brine volume. This work systematically compared the desalination performance of CDI when single-pass and SF discharge operation modes were respectively used. Results showed that while the SF discharge operation could achieve remarkably higher water recovery (>80 %), this inevitably resulted in the deterioration of CDI performance when the feed contained higher concentrations (5 mM) of Ca 2+ and SO 4 2− . Compared to the electrodes, the spacer and the desalination chamber could be more vulnerable to scaling in brackish water desalination. With the formation of glauberite and gypsum in SF discharge operation, the carbon materials from the electrodes constantly existed on the scaled spacer, which contributed to the blocking of the flow path and a significant increase in pressure loss. This study provides insight into the scaling mechanism for SF discharge in multi-cycle operation, which is crucial for the design of CDI materials and optimization of operating protocols for brackish water desalination.
研究领域:
环境科学
·
水资源工程
·
化学工程
✓ 已验证
DOI
高影响因子
WATER RESEARCH
·
2024
·
IF 11.4
Liang Luo,Tao Liu,Jiazhou He,Jinxing Ma,Han-Qing Yu
Flow-electrode capacitive deionization (FCDI) is a promising electrically driven technology for brackish water desalination, but it suffers from scaling issues in the concentrate chamber when treating brackish water with high levels of SO 4 2− and Ca 2+ . In addition, how the key components ( e.g. , flow electrodes, spacer and ion exchange membranes) induce scaling in the concentrate chamber remains poorly understood. Therefore, this study systematically investigated the roles of the FCDI's components playing in the scaling process. Results showed substantial pressure loss in the concentrate chamber, which increased by 108% due to the scaling. The characterization results revealed that the scale attached to the surface of the spacer and membranes was gypsum. Gypsum crystallization experiments highlighted the crucial role of the cation exchange membrane and spacer in the heterogeneous nucleation process, which significantly shortened the induction time compared to the homogeneous nucleation process. The surface properties, such as the surface energy and surface charge, were found closely related to gypsum nucleation. In summary, the results of this work pave the way for understanding the gypsum nucleation process in FCDI continuously desalinating brackish hard water, potentially aiding in scaling removal and system optimization for broader environmental applications.
研究领域:
环境科学
·
水处理技术
✓ 已验证
DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2022
·
IF 8.431
Liang Luo,Qiang He,Siqi Chen,Dongxu Yang,Yi Chen
Flow-electrode capacitive deionization (FCDI) has shown a robust desalination performance, in which the electrode materials play a crucial role. However, commercial activated carbon (AC) commonly with relatively poor conductivity, which can be a limit to the desalination process . To address this issue, we successfully prepared ZIF-8 derived nanocarbon materials (Zx, X = 0, 1, 2, 3, the number representing the activator ratio) via a pyrolysis activation procedure as electrode materials for FCDI desalination. The results manifested that Z3 achieved desalination rates of 0.0403 and 0.094 mg min −1 cm −2 in the isolated closed cycle (ICC) and the short-circuited closed cycle (SCC) mode, respectively, at 1.2 V with only 5 wt% carbon loading. The desalination rate of Z3 in the SCC mode was improved with flow rates and influent salt concentrations increase, reaching 0.278 mg min −1 cm −2 under a continuous operation. In the ICC mode, it was found that the adsorption capacity of the Zx sample was positively correlated with its specific surface area. The superior performance of Z3 could be attributed to the high conductivity, large specific surface area and well-developed pores. Overall, this work provided new insights and references for electrode material's application to FCDI desalination.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Biosensors-Basel
·
2024
·Vol. 14
·期 6
·271
·
IF 4.9
Wenyan Shi,Zi Ye,Qin Yang,Jianhua Zhou,Jiasi Wang,Xinming Huo
The drug detection technology plays a pivotal role in the domains of pharmaceutical regulation and law enforcement. In this study, we introduce a method that combines thermal desorption corona discharge ionization (TD-CDI) with mass spectrometry for efficient drug detection. The TD-CDI module, characterized by its compact and simple design, enables the separation of analytes within seconds and real-time presentation of one or two analyte peaks on the mass spectrum most of the time, which reduces matrix interference and improves detection performance. Through experimental investigation, we studied the characteristics of TD-CDI for analyte separation and detection, even with the same mass number, and optimized the TD-CDI approach. TD-CDI-MS was employed for the rapid detection of drugs in various traditional medicine, food products, and human samples. Additionally, by utilizing TD-CDI for segmented hair direct analysis, it becomes possible to trace the drug usage cycle of individuals. This underscores the feasibility of the proposed analytical method within the realm of drug detection.
研究领域:
分析化学
·
药理学
·
法医学
✓ 已验证
DOI
PubMed
高影响因子
WATER RESEARCH
·
2021
·
IF 11.236
Liang Luo,Qiang He,Zixin Ma,Duo Yi,Yi Chen,Jinxing Ma
Flow electrode capacitive deionization (FCDI) is a promising electrochemical technique for brackish water desalination; however, there are challenges in estimating the distribution of resistance and energy consumption inside a FCDI system, which hinders the optimization of the rate-limiting compartment. In this study, energy consumption of each FCDI component (e.g., flow electrodes, membranes and desalination chamber) was firstly described by using in situ potential measurement (ISPM). Results of this study showed that the energy consumption (EC) of the flow electrodes dominated under most conditions. While an increase in the carbon black content in the flow electrodes could improve the energy efficiency of the electrode component, consideration should be given to the contribution of ion exchange membranes (IEMs) and the desalination chamber to the EC. Based on the above analysis, system optimization was carried out by introducing IEMs with relatively low resistance and/or packing the desalination chamber with titanium meshes. Results showed that the voltage-driven desalination capability was increased by 39.3% with the EC reduced by 17.5% compared to the control, which overcame the tradeoff between the kinetic and energetic efficiencies. Overall, the present work facilitates our understanding of the potential drops across an FCDI system and provides insight to the optimization of system design and operation.
研究领域:
环境科学
·
电化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2022
·
IF 10.319
Zhao Song,Lingyu Li,Yidi Chen,Xiaoguang Duan,Nanqi Ren
Biochars are low-cost and sustainable materials for environmental technologies. In this work, we prepared three biochars using pomelo peel (P-BC), algae (A-BC), and corncob (C-BC) to recover Cd 2+ from wastewater via capacitive deionisation (CDI). A-BC possesses the highest amount of mesopores and nitrogen functionality and attains the highest removal of Cd 2+ via physical adsorption. For the electro-sorption capacity, C-BC and A-BC perform better capacitive removal of Cd 2+ than P-BC due to the smaller charge-transfer and mass-transfer resistances. Also, this work investigated the impacts of surface morphology , cell voltage, NaCl, initial pH, and Cd 2+ concentrations on Cd 2+ capacitive removal and electrode regeneration performances. The results indicated that A-BC and C-BC may be prospective materials for Cd 2+ removal from wastewater by CDI. However, the presence of competing cations at high concentrations may influence the removal of Cd 2+ at a low level, requiring the modification of A-BC and C-BC in future work.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2020
·
IF 7.489
Zhe Li,Shudi Mao,Ying Yang,Zhuo Sun,Ran Zhao
Capacitive deionization (CDI) is considered one of the most promising desalination technologies for obtaining fresh water from saline water. In this work, we synthesized a hollow core–shell Co-MOF@Fe/Co-LDH (Co-Fe-LDH) material by developing a strategy to simultaneously grow Co/Fe-LDH on the surface of a Co-MOF precursor in situ. Owing to the increase in the specific surface area of the hollow structure and the Faradaic process of a layered double hydroxide (LDH), the Co-Fe-LDH material exhibits high electrical double layer (EDL) capacitance and pseudocapacitance, which significantly improves the salt adsorption of the material during CDI (34.2 mg/g in a 600 mg/L NaCl solution at 1.2 V). The adsorption for NaCl in this work is approximately 2.5 times the maximum salt adsorption capacity (SAC) of LDH materials applied in nonmembrane CDI (NMCDI). This work may provide a promising model for the application of hollow LDH materials that exhibit pseudocapacitance in CDI.
研究领域:
材料科学
·
环境工程
·
海水淡化技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zhuannian Liu,Benlong Wei,Kai Liu,Liping Wang
Molybdenum disulfide (MoS 2 ), as an appealing Faradaic material for efficient capacitive deionization (CDI), is limited by unsatisfactory electrical conductivity, inferior removal rate, and restacking. Herein, we develop a CNT/PPy/MoS 2 ternary composite using a robust 3D conductive interconnected structure CNT/PPy, constructed from multi-walled carbon nanotubes (MWCNTs) and polypyrrole (PPy) doped with dodecyl benzene sulfonate (DBS - ), as the growing substrate to mitigate the aggregation of MoS 2 nanoflakes. In this design, CNT/PPy ameliorates the wettability of the composite, provides convenient movement pathways, a fast charge transport rate, and facilitates ions diffusion process. Moreover, reinforced dispersibility and enlarged interlayer spacing of MoS 2 nanoflakes supply sufficient embedded sites for ion uptake and rapid transfer. Meanwhile, tight chemical coupling of Mo-N-C bonds can maintain the structural integrity of the composite electrode. Particularly, the symmetrical electrode configuration was established to address the kinetical unbalance of HCDI system. Consequently, the CNT/PPy/MoS 2 displays a large specific capacitance of 160.83 F g −1 at 5 mV s −1 , which is nearly 4.33 times that of MoS 2 (37.17 F g −1 ). The optimized CNT/PPy/MoS 2 cell achieves a maximum desalination capacity of 24.8 mg g −1 , ultra-high deionization rate of 5.24 mg g −1 min −1 , and superior capacity retention rate of 92.7% over 25 cycles. In addition, Na + ions were captured by the joint action of cation-exchange of DBS - -doped PPy, electrostatic adsorption of CNTs, and intercalation reaction of MoS 2 . The proposed composite structural design and electrode configuration should be a potential avenue to realize highly efficient deionization.
研究领域:
材料科学
·
环境科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2022
·
IF 13.4
Liang Luo,Qiang He,Duo Yi,Daoyuan Zu,Jinxing Ma,Yi Chen
Reversible electrochemical separation based on flow electrodes ( e.g. , flow-electrode capacitive deionization (FCDI)) is promising to desalinate brackish water, a reliable alternative source of freshwater. The deployment of redox mediators (RMs) in FCDI offers an energy-efficient means to improve the process performance, but the nature of the RMs-mediated charge transfer remains poorly understand. We therefore systematically investigated commonly-used RMs including sodium anthraquinone-2-sulfonate (AQS), 4-hydroxy-2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), hydroquinone (HQ) and ferricyanide ([Fe(CN) 6 ] 3− ). Results showed that the desalination rate could be increased by over 260% with the addition of 10 mM [Fe(CN) 6 ] 3− . The lowest efficiency of AQS among the RMs should be ascribed to its reduction potential of −0.84 V ( vs . Ag/AgCl) exceeding the potential (−0.48 V) of the negatively charged current collector at 1.2 V. While aqueous TEMPO and HQ could facilitate salt removal, their loss of efficiencies upon sorption onto the carbon surface indicated the insignificant pseudocapacitive contribution to ion migration. In-situ cyclic voltammetry measurements demonstrated the crucial role of the indirect charging of the flowable carbon materials to enhance the desalination performance in RMs-mediated FCDI. To sum up, results of this work pave a way to understand the RMs-mediated charge transfer and ion migration in FCDI, which would serve the purpose of design and optimization of the flow electrode systems for wider environmental applications.
研究领域:
环境工程
·
电化学
·
水处理技术
·
节能脱盐
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）