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
DESALINATION
·
2024
·
IF 8.3
Zhipeng Tang,Yongmei Li,Kaixuan Tan,Guohui Wang,Chunguang Li,Longcheng Liu,Zhenzhong Liu
In-situ leaching (ISL) causes non-negligible groundwater pollution. It is urgent to remediate the groundwater after ISL activities. In this study, we evaluated the effectiveness of flow electrode capacitive deionization (FCDI) to treat a simulated groundwater, the uranium (U) and SO 4 2− concentration of which are comparable to groundwater in acid in-situ leaching (AISL) uranium mine for the first time. Moreover, the removal mechanism of U and SO 4 2− were investigated in-depth. It is found that the operational mode, applied voltage and initial SO 4 2− concentration significantly affect the removal of U and SO 4 2− by FCDI. The removal efficiency of U and SO 4 2− were above 98 % at 75 min under optimal condition, although U in groundwater mainly existed in the form of uncharged UO 2 (SO 4 ), followed by UO 2 2+ and UO 2 (SO 4 ) 2 2− . UO 2 2+ and UO 2 (SO 4 ) 2 2− in groundwater migrated into the two poles and were quickly absorbed by flow electrode, which promoted the dissociation of UO 2 (SO 4 ) or complexation of UO 2 (SO 4 ) with SO 4 2− . In addition, the anion exchange membrane can absorb UO 2 (SO 4 ) through complexation. These resulted in the efficient removal of U(VI). FCDI can reduce the U and SO 4 2− concentration of the contaminated water ( C U = 10 mg L −1 , C SO4 2− = 5 g L −1 ) to a value lower than the Chinese emission limit (U: 300 μg L −1 ; SO 4 2− : 250 mg L −1 ) even after 18 cycles with each cycle operated for 120 min, which informed that FCDI system using activated carbon is of great potential for acidic contaminated water treatment.
研究领域:
环境科学
·
水处理工程
✓ 已验证
产品关联
DOI
高影响因子
WATER RESEARCH
·
2020
·
IF 9.13
Longqian Xu,Yunfeng Mao,Yang Zong,Deli Wu
Salt removal from seawater/wastewater using flow-electrode capacitive deionization (FCDI) is of particular interest, but scale-up desalination is limited by low water production, high energy consumption and complex cell configuration. In this study, an innovative FCDI system is described that uses integrated desalination modules equipped with membrane-current collector (MCC) assembly, and thereby named as MCC-FCDI system. A single desalination module design provides an average salt removal rate ( ASRR , 0.3 – 0.44 µmol/(cm 2 ·min)) close to that of the classic FCDI system (with a graphite current collector design), but the design requires a much lower infrastructure investment, device size and energy cost. More importantly, our design enables simultaneous operation of multiple modules in the shared flow-electrode tank, easily realizing scale-up desalination. Evidence is provided by the results of the multi-module operation: multi-modules isolated closed-cycle (MICC) and multi-modules short-circuited closed-cycle (MSCC). For instance, the MICC configuration showing nearly twice the desalination performance over ~ 50 h of operation compared to that of the single ICC operation. The results indicated that in addition to making the device suitable for practical application, the Ti-mesh MCC with a woven network enables the flow electrode to achieve substantial ion adsorption capacity due to the efficient update of fresh carbon particles. In short, the results of this study showed that MCC-FCDI is a promising desalination system for scale-up applications, providing a new reference and guidance for device design.
研究领域:
环境工程
·
材料科学
·
水处理技术
✓ 已验证
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2022
·Vol. 7
·期 2
·398-408
·
IF 6.813
Zhi Zou,Shuo Meng,Xiaolei Bian,Longcheng Liu
The generation of electricity from salinity difference energy between seawater and freshwater through a Capacitive Mixing (CapMix) system with solid electrodes was limited by intermittent energy production. In this study, a single-cell CapMix system using flow-electrode (F-CapMix) with a cross-chamber configuration was examined to produce electricity continuously from simulated seawater and freshwater. The effects of the flow-electrode electrolyte concentration, activated carbon loading, amounts of carbon black, and connected external resistance on the system performance were investigated. The results suggest that the system performance can be enhanced by increasing the activated carbon loading and carbon black amounts. Furthermore, to achieve the maximum power density of the system, the external resistance should be matched to the internal resistance. The maximum power density of the presented single-cell F-CapMix system was 74.3 mW m−2, which was comparable to those of previous CapMix and F-CapMix systems. In addition, this study also reveals that using only carbon black as the flow electrode is capable of producing electricity continuously for long-term operation. In summary, these results indicate the potential of F-CapMix and provide developing directions for further optimization.
研究领域:
环境科学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）