Selective ion adsorption with pilot-scale membrane capacitive deionization (MCDI): arsenic, ammonium and manganese removal

2020 ◽  
Vol 198 ◽  
pp. 163-169
Author(s):  
Edgardo E. Cañas Kurz ◽  
Ulrich Hellriegel ◽  
Vu T. Luong ◽  
Jochen Bundschuh ◽  
Jan Hoinkis
Keyword(s):  
Pilot Scale ◽  
Ion Adsorption ◽  
Capacitive Deionization ◽  
Manganese Removal

scholarly journals Kinetic Modeling and Mechanisms of Manganese Removal from Alkaline Mine Water Using a Pilot Scale Column Reactor

Minerals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 99
Author(s):  
Shigeshi Fuchida ◽  
Shota Tajima ◽  
Takuro Nishimura ◽  
Chiharu Tokoro
Keyword(s):  
Kinetic Modeling ◽  
Mine Water ◽  
Pilot Scale ◽  
Silica Sand ◽  
Edge Structure ◽  
Column Reactor ◽  
Molar Ratios ◽  
Manganese Removal ◽  
Water Ph ◽  
Xanes Analysis

Manganese (Mn) is a major element in various aqueous and soil environments that is sometimes highly concentrated in mine water and other mineral processing wastewater. In this study, we investigated Mn removal from alkaline mine water (pH > 9) with an Mn-coated silica sand packed into a pilot-scale column reactor and examined the specific reaction mechanism using X-ray absorption near-edge structure (XANES) analysis and geochemical kinetic modeling. The kinetic effect of dissolved Mn(II) removal by birnessite (δ-Mn(IV)O2) at pH 6 and 8 was evaluated at different Mn(II)/Mn(IV) molar ratios of 0.1–10. Our results confirmed the positive effect of the presence of δ-MnO2 on the short-term removal (60 min) of dissolved Mn. XANES analysis results revealed that δ-MnO2 was more abundant than Mn(III)OOH in the reactor, which may have accumulated during a long-term reaction (4 months) after the reactor was turned on. A gradual decrease in dissolved Mn(II) concentration with depth was observed in the reactor, and comparison with the kinetic modeling result confirmed that δ-MnO2 interaction was the dominant Mn removal mechanism. Our results show that δ-MnO2 contents could play a significant role in controlling Mn removability from mine water in the reactor.

Estimation of ion adsorption using iterative analytical model in capacitive deionization process

2018 ◽  
Vol 116 ◽  
pp. 75-82 ◽  
Author(s):  
Mohammed Shafiq ◽  
Karthik Laxman ◽  
Joydeep Dutta
Keyword(s):  
Analytical Model ◽  
Ion Adsorption ◽  
Capacitive Deionization

scholarly journals Towards Electrochemical Water Desalination Techniques: A Review on Capacitive Deionization, Membrane Capacitive Deionization and Flow Capacitive Deionization

Membranes ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 96 ◽  
Author(s):  
Gbenro Folaranmi ◽  
Mikhael Bechelany ◽  
Philippe Sistat ◽  
Marc Cretin ◽  
Francois Zaviska
Keyword(s):  
Brackish Water ◽  
Research Area ◽  
Water Desalination ◽  
Ion Adsorption ◽  
Capacitive Deionization ◽  
Major Research ◽  
Modus Operandi ◽  
Solvated Ions ◽  
The 1960S ◽  
Simple Potential

Electrochemical water desalination has been a major research area since the 1960s with the development of capacitive deionization technique. For the latter, its modus operandi lies in temporary salt ion adsorption when a simple potential difference (1.0–1.4 V) of about 1.2 V is supplied to the system to temporarily create an electric field that drives the ions to their different polarized poles and subsequently desorb these solvated ions when potential is switched off. Capacitive deionization targets/extracts the solutes instead of the solvent and thus consumes less energy and is highly effective for brackish water. This paper reviews Capacitive Deionization (mechanism of operation, sustainability, optimization processes, and shortcomings) with extension to its counterparts (Membrane Capacitive Deionization and Flow Capacitive Deionization).

Competitive mechanism of ammonia, iron and manganese for dissolved oxygen using pilot-scale biofilter at different dissolved oxygen concentrations

2015 ◽  
Vol 16 (3) ◽  
pp. 766-774 ◽  
Author(s):  
Qingfeng Cheng
Keyword(s):  
Dissolved Oxygen ◽  
Pilot Scale ◽  
Turbidity Removal ◽  
Manganese Removal ◽  
Start Up ◽  
Competitive Mechanism ◽  
Iron And Manganese ◽  
Oxygen Concentrations

In this study, the competitive mechanism of ammonia, iron and manganese for dissolved oxygen (DO) in a biofilter was investigated, and a new start-up method of a biofilter for ammonia, iron and manganese removal was approved, which can effectively shorten the start-up period from 3–4 months to 51 days. The results demonstrated that when DO was sufficient (about 8 mg · L−1), ammonia, iron and manganese could be completely removed. When DO decreased from 6.5 to 4 mg · L−1, the concentration of ammonia in the effluent increased accordingly, though iron and manganese were removed efficiently. When DO was as low as 3 mg · L−1, only iron was removed, whereas most of the ammonia and manganese still existed in the effluent. In addition, the oxidizing rates of the pollutants were not affected significantly with DO decrease. Turbidity removal in the biofilter was also investigated, and the results demonstrated that the turbidity decreased to less than 0.5 NTU at 0.4 m depth of the filter.

scholarly journals Diffusion-bonded CNT carpets for fundamental CDI studies

2012 ◽  
Vol 1407 ◽  
Author(s):  
R. Enright ◽  
R. Mitchell ◽  
H. Mutha ◽  
C. Lv ◽  
M. Christiansen ◽  
...  
Keyword(s):  
Cyclic Voltammetry ◽  
Carbon Nanotube ◽  
Pore Structure ◽  
Electrochemical Capacitor ◽  
Water Desalination ◽  
Carbon Electrodes ◽  
Aqueous Electrolytes ◽  
Ion Adsorption ◽  
Capacitive Deionization ◽  
Multi Scale

ABSTRACTUncertainty about future energy and water supplies suggests a pressing need to develop efficient technologies for water desalination. Capacitive deionization (CDI), a method that captures ions in the electrical double layer (EDL) of an electrochemical capacitor, is a promising technology that can potentially fulfill those requirements. Similar to supercapacitors, ideal CDI electrodes should have a large electrolyte-accessible specific surface area available for ion adsorption with rapid charging/discharging characteristics. Unlike supercapacitors, CDI electrodes are required to operate in aqueous electrolytes with low ionic concentrations in a non-linear charging regime. To explore this practically and theoretically important regime, we developed robust, electrochemically-compatible carbon nanotube (CNT) carpet electrodes that posses a well-defined and uniform pore structure that is more readily analyzed in comparison to the random and multi-scale pore structure of typical carbon electrodes. The fabricated electrodes were characterized using cyclic voltammetry and potentiostatic charging in aqueous NaCl solutions (no = 20 - 90 mM) using a three electrode setup. Examination of the CV and potentiostatically-measured capacitances were consistent with EDL behavior dictated by the Stern layer. However, some deviations from the expected behavior were observed with increasing salt concentration during potentiostatic testing.

Modeling Manganese Removal in a Pilot-Scale Postfiltration Contactor

2015 ◽  
Vol 107 (2) ◽  
pp. E109-E119 ◽  
Author(s):  
Kevin A. Bierlein ◽  
William R. Knocke ◽  
John E. Tobiason ◽  
Archana Subramaniam ◽  
Minh Pham ◽  
...  
Keyword(s):  
Pilot Scale ◽  
Manganese Removal
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