Selective removal of specific anions using composite carbon electrodes coated with an anion-exchange resin powder

Ji-Won Son,Hyun-Cheul Roh,Jae-Hwan Choi 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.1

The selective removal of specific ions was explored by using a capacitive deionization (CDI) system with a selective composite carbon electrode (SCCE). An SCCE was manufactured by coating a carbon electrode with anion-exchange resin (AER) powders. The correlation between the characteristics of the AERs and ion selectivity was analyzed, and the ion selectivity of the SCCE was verified through CDI experiments with a mixed solution of chloride, nitrate, and sulfate ions. The adsorption equilibrium results of the AERs showed that the ion selectivity of an AER was greatly influenced by its ion-exchange capacity (IEC). The higher the IEC value was, the higher the selectivity for the divalent sulfate ion, whereas the smaller the IEC was, the higher the selectivity for the nitrate ion. The CDI experimental results show that the equivalent fraction of ions adsorbed to the SCCE was consistent with the result of the adsorption equilibrium test. Therefore, the ion selectivity of the SCCE was governed by the ion selectivity of the AER coated on the electrode surface. Notably, as the current density applied to the cell increased, the AER could not maintain an adsorption equilibrium state, which resulted in a decrease in the ion selectivity of the SCCE.

이온교환수지 분말이 코팅된 탄소전극을 이용한 음이온 혼합용액에서 Nitrate 이온의 선택적 제거율 향상

최재환 ( Jin Hee Yeo ),여진희 ( Jae Hwan Choi ) 한국공업화학회 2013 공업화학 Vol.24 No.1

혼합용액에서 nitrate 이온을 선택적으로 제거하기 위해 복합탄소전극을 제조하였다. 질산이온 선택성 수지(BHP55, Bonlite Co.) 분말을 탄소전극 표면에 코팅하여 전극을 제조하였다. 제조한 전극으로 BHP55 셀을 제작하여 chloride, nitrate, sulfate 이온이 혼합된 용액에 대해 축전식 탈염 실험을 수행하였다. 그리고 BHP55 셀에서의 질산 이온 제거량 을 이온교환막을 결합한 MCDI 셀의 결과와 비교하였다. BHP55 셀에서 이온의 총 흡착량은 MCDI 셀에서 보다 31% 증가한 38.3 meq/m 2를 나타냈다. 또한 BHP55 셀에서 질산 이온의 흡착량은 15.9 meq/m 2 (전체 흡착량의 42%)이었고, 이는 MCDI 셀에서 보다 2.1배 큰 것으로 나타났다. 실험결과 제조한 복합탄소전극은 음이온 혼합용액에서 질산 이온을 선택적으로 제거하는데 매우 효과적임을 알 수 있었다. We fabricated a composite carbon electrode to remove nitrate ions selectively from a mixed solution of anions. The electrode was fabricated by coating the surface of a carbon electrode with the nitrate-selective anion exchange resin (BHP55, Bonlite Co.) powder. We performed capacitive deionization (CDI) experiments on a mixed solution containing chloride, nitrate, and sulfate ions using a BHP55 cell constructed with the fabricated electrode. The removal of nitrate ions in the BHP55 cell was compared to that of a membrane capacitive deionization (MCDI) cell constructed with ion exchange membranes. The total quantity of ions adsorbed in BHP55 cell was 38.3 meq/m 2 , which is 31% greater than that of MCDI cell. In addition, the number of nitrate adsorption in the BHP55 cell was 15.9 meq/m 2 (42% of total adsorption), 2.1 times greater than the adsorption in the MCDI cell. The results showed that the fabricated composite carbon electrode is very effective in the selective removal of nitrate ions from a mixed solution of anions.

Sodium Ion-Selective Membrane Electrode Based on Dibenzopyridino-18-Crown-6

Tavakkoli, Nahid Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.10

A sodium ion- selective electrode based on dibenzopyridino-18-crown-6 as membrane carrier was successfully prepared. The electrode exhibits a Nernstian response for $Na^+$ ions within the concentration range of $1.0\;{\times}\;10^{-4}-1.0\;{\times}\;10^{-1}$ M. The response time of the sensor is 20 s. The sodium ion-selective electrode exhibited comparatively good selectivities with respect to alkali, alkaline earth and some transition metal ions.

UO₂²⁺ Ion-Selective Membrane Electrode Based on a Naphthol-Derivative Schiff's Base 2,2'-[1,2-Ethandiyl bis(nitriloethylidene)]bis(1-naphthalene)

Shamsipur, Mojtaba,Saeidi, Mahboubeh,Yari, Abdullah,Yaganeh-Faal, Ali,Mashhadizadeh, Mohammad Hossein,Azimi, Gholamhasan,Naeimi, Hossein,Sharghi, Hashem Korean Chemical Society 2004 Bulletin of the Korean Chemical Society Vol.25 No.5

A new PVC membrane electrode for $UO_2^{2+}$ ion based on 2,2'-[1,2-ethanediyl bis (nitriloethylidene)]bis(1-naphthalene) as a suitable ionophore was prepared. The electrode exhibites a Nernstian response for $UO_2^{2+}$ ion over a wide concentration range ($1.0{\times}10^{-1}-1.0{\times}10^{-7}$M) with a slope of 28.5 ${\pm}$ 0.8 mV/decade. The limit of detection is $7.0{\times}10^{-8}$M. The electrode has a response time of < 20 s and a useful working pH range of 3-4. The proposed membrane sensor shows good discriminating abilities towards $UO_2^{2+}$ ion with regard to several alkali, alkaline earth transition and heavy metal ions. It was successfully used to the recovery of uranyl ion from, tap water and, as an indicator electrode, in potentiometric titration of $UO_2^{2+}$ ion with Piroxycam.

Development of a New Copper(II) Ion-selective Poly(vinyl chloride) Membrane Electrode Based on 2-Mercaptobenzoxazole

Morteza Akhond*,Mehrorang Ghaedi,Javad Tashkhourian 대한화학회 2005 Bulletin of the Korean Chemical Society Vol.26 No.6

Copper(II) ion-selective PVC membrane electrode based on 2-mercaptobenzoxazole as a new ionophore and o-nitrophenyl octyl ether (o-NPOE) as plasticizer is proposed. This electrode revealed good selectivity for Cu2+ over a wide variety of other metal ions. Effects of experimental parameters such as membrane composition, nature and amount of plasticizer, and concentration of internal solution on the potential response of Cu2+ sensor were investigated. The electrode exhibits good response for Cu2+ in a wide linear range of 5.0 ´106-1.6 ´ 102 mol/L with a slope of 29.2 ± 2.0 mV/decade. The response time of the sensor is less than 10 s, and the detection limit is 2.0 ´106 mol/L. The electrode response was stable in pH range of 4-6. The lifetime of the electrode was about 2 months. The electrode revealed comparatively good selectivities with respect to many alkali, alkaline earth, and transition metal ions.

Development of a New Copper(II) Ion-selective Poly(vinyl chloride) Membrane Electrode Based on 2-Mercaptobenzoxazole

Akhond, Morteza,Ghaedi, Mehrorang,Tashkhourian, Javad Korean Chemical Society 2005 Bulletin of the Korean Chemical Society Vol.26 No.6

Copper(II) ion-selective PVC membrane electrode based on 2-mercaptobenzoxazole as a new ionophore and o-nitrophenyl octyl ether (o-NPOE) as plasticizer is proposed. This electrode revealed good selectivity for $Cu^{2+}$ over a wide variety of other metal ions. Effects of experimental parameters such as membrane composition, nature and amount of plasticizer, and concentration of internal solution on the potential response of $Cu^{2+}$ sensor were investigated. The electrode exhibits good response for $Cu^{2+}$ in a wide linear range of 5.0 ${\times}$ 10−.6-1.6 ${\times}$ $10^{-2}$ mol/L with a slope of 29.2 ${\pm}$ 2.0 mV/decade. The response time of the sensor is less than 10 s, and the detection limit is 2.0 ${\times}$ $10^{-6}$ mol/L. The electrode response was stable in pH range of 4-6. The lifetime of the electrode was about 2 months. The electrode revealed comparatively good selectivities with respect to many alkali, alkaline earth, and transition metal ions.

An Automated Water Nitrate Monitoring System based on Ion-Selective Electrodes

( Woo Jae Cho ),( Dong-wook Kim ),( Dae Hyun Jung ),( Sang Sun Cho ),( Hak-jin Kim ) 한국농업기계학회 2016 바이오시스템공학 Vol.41 No.2

Purpose: In-situ water quality monitoring based on ion-selective electrodes (ISEs) is a promising technique because ISEs can be used directly in the medium to be tested, have a compact size, and are inexpensive. However, signal drift can be a major concern with on-line management systems because continuous immersion of the ISEs in water causes electrode degradation, affecting the stability, repeatability, and selectivity over time. In this study, a computer-based nitrate monitoring system including automatic electrode rinsing and calibration was developed to measure the nitrate concentration in water samples in real-time. Methods: The capabilities of two different types of poly(vinyl chloride) membrane-based ISEs, an electrode with a liquid filling and a carbon paste-based solid state electrode, were used in the monitoring system and evaluated on their sensitivities, selectivities, and durabilities. A feasibility test for the continuous detection of nitrate ions in water using the developed system was conducted using water samples obtained from various water sources. Results: Both prepared ISEs were capable of detecting low concentrations of nitrate in solution, i.e., 0.7 mg/L NO3-N. Furthermore, the electrodes have the same order of selectivity for nitrate: NO3 - >> HCO3 - > Cl - > H2PO4 - > SO4 2- , and maintain their sensitivity by > 40 mV/decade over a period of 90 days. Conclusions: The use of an automated ISE-based nitrate measurement system that includes automatic electrode rinsing and two-point normalization proved to be feasible in measuring NO3-N in water samples obtained from different water sources. A one-to-one relationship between the levels of NO3-N measured with the ISEs and standard analytical instruments was obtained.

Sensing Nitrate and Potassium Ions in Soil Extracts Using Ion-Selective Electrodes

Kim, H.J.,Sudduth Kenneth A.,Hummel John W. Korean Society for Agricultural Machinery 2006 바이오시스템공학 Vol.31 No.6

Automated sensing of soil macronutrients would allow more efficient mapping of soil nutrient spatial variability for variable-rate nutrient management. The capabilities of ion-selective electrodes for sensing macronutrients in soil extracts can be affected by the presence of other ions in the soil itself as well as by high concentrations of ions in soil extractants. Adoption of automated, on-the-go sensing of soil nutrients would be enhanced if a single extracting solution could be used for the concurrent extraction of multiple soil macronutrients. This paper reports on the ability of the Kelowna extractant to extract macronutrients (N, P, and K) from US Corn Belt soils and whether previously developed PVC-based nitrate and potassium ion-selective electrodes could determine the nitrate and potassium concentrations in soil extracts obtained using the Kelowna extractant. The extraction efficiencies of nitrate-N and phosphorus obtained with the Kelowna solution for seven US Corn Belt soils were comparable to those obtained with IM KCI and Mehlich III solutions when measured with automated ion and ICP analyzers, respectively. However, the potassium levels extracted with the Kelowna extractant were, on average, 42% less than those obtained with the Mehlich III solution. Nevertheless, it was expected that Kelowna could extract proportional amounts of potassium ion due to a strong linear relationship ($r^2$ = 0.96). Use of the PVC-based nitrate and potassium ion-selective electrodes proved to be feasible in measuring nitrate-N and potassium ions in Kelowna - soil extracts with almost 1 : 1 relationships and high coefficients of determination ($r^2$ > 0.9) between the levels of nitrate-N and potassium obtained with the ion-selective electrodes and standard analytical instruments.

싸이크로스포린을 이용한 고분자막 전위차 전극

이인숙 한국분석과학회 2005 분석과학 Vol.18 No.6

The main component governing selectivity in ion-selective electrodes and optodes is the ionophore. For this reason, a member of natural products that possess selective ion-binding properties have long been sought after. By applying this principle, the performance of cyclosporin used as neutral carriers for calcium selective polymeric membrane electrode was investigated. The calcium ion-selective electrode based on cyclosporin gave a good Nernstian response of 26.6 mV per decade for calcium ion in the activity range 1×10−6 M to 1×10−2 M. The optimized calcium ion-selective electrode displayed very comparable selectivity for Ca2+ ion against alkali and alkaline earth metal ions, Na+, and Mg2+ in particular.

Reuse of municipal wastewater via membrane capacitive deionization using ion-selective polymer-coated carbon electrodes in pilot-scale

Kim, David Inhyuk,Dorji, Pema,Gwak, Gimun,Phuntsho, Sherub,Hong, Seungkwan,Shon, Hokyong Elsevier 2019 CHEMICAL ENGINEERING JOURNAL -LAUSANNE- Vol.372 No.-

<P><B>Abstract</B></P> <P>This study investigated membrane capacitive deionization (MCDI) at a pilot-scale using ion-selective polymer-coated carbon electrodes for wastewater reuse. Several issues have been addressed to verify the suitability of MCDI for wastewater reclamation: electrosorption performance, removal efficiency and selectivity of ions present in wastewater, optimization of operating conditions, and performance degradation in long-term caused by the accumulation of organic contaminants. The coated electrodes had better adsorption capacities and charge efficiencies than the conventional MCDI system, which was attributed to their low electrical resistance induced by the thin coated layer. The pilot-scale MCDI test cell involved 50 pairs of anion- and cation-selective electrodes and achieved good removal efficiency of ions from the wastewater effluent, particularly for problematic charged impurities, such as nitrate (NO<SUB>3</SUB> <SUP>−</SUP>) (up to 91.08% of NO<SUB>3</SUB> <SUP>−</SUP> was removed). Increasing the flow rate and reducing the applied potential were shown to be efficient for achieving better water quality by enhancing the NO<SUB>3</SUB> <SUP>−</SUP> selectivity. Last, the 15 d operation showed good reproducibility in electrosorption and regeneration for the coated electrodes, despite the fact that high concentrations of organics were contained in the wastewater feed solution (12.4 mg/L of dissolved organic carbon).</P> <P><B>Highlights</B></P> <P> <UL> <LI> MCDI was probed for wastewater reuse in pilot-scale using ion selective electrodes. </LI> <LI> The coated electrodes showed better performance attributing to its low resistivity. </LI> <LI> NO<SUB>3</SUB> <SUP>−</SUP> was selectively removed attributing to its high permselectivity through AEM. </LI> <LI> Faster flow rate and lower potential enhanced NO<SUB>3</SUB> <SUP>−</SUP> selectivity in single-pass mode. </LI> <LI> The flat coated layer kept organic substances from accumulating on the surface. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>