Determining time-weighted average concentrations of nitrate and ammonium in freshwaters using DGT with ion exchange membrane-based binding layers

2016 ◽  
Vol 18 (12) ◽  
pp. 1530-1539 ◽  
Author(s):  
Jianyin Huang ◽  
William W. Bennett ◽  
David T. Welsh ◽  
Peter R. Teasdale
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Weighted Average ◽  
Ion Exchange Membrane ◽  
Time Weighted Average ◽  
Exchange Membrane

Commercially-available AMI-7001 anion exchange and CMI-7000 cation exchange membranes were utilised as binding layers for DGT measurements of NO3–N and NH4–N in freshwaters.

Green synthesis of nanoscale anion exchange resin for sustainable water purification

2018 ◽  
Vol 4 (10) ◽  
pp. 1685-1694 ◽  
Author(s):  
Abhispa Sahu ◽  
Kayla Blackburn ◽  
Kayla Durkin ◽  
Tim B. Eldred ◽  
Billy R. Johnson ◽  
...  
Keyword(s):  
Thin Film ◽  
Ion Exchange ◽  
Green Synthesis ◽  
Anion Exchange ◽  
Water Purification ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Ion Exchange Membrane ◽  
Exchange Membrane ◽  
Persistent Contaminants

A new water purification ion exchange membrane has been synthesized using an all-aqueous and sustainable process. These thin film membranes exhibit a pin hole free, mesoporous architecture that rapidly removes several classes of pervasive and persistent contaminants from water.

scholarly journals Custom-Made Ion Exchange Membranes at Laboratory Scale for Reverse Electrodialysis

Membranes ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 145 ◽  
Author(s):  
Liliana Villafaña-López ◽  
Daniel M. Reyes-Valadez ◽  
Oscar A. González-Vargas ◽  
Victor A. Suárez-Toriello ◽  
Jesús S. Jaime-Ferrer
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Structural Modification ◽  
Anion Exchange Membrane ◽  
Laboratory Scale ◽  
Cation Exchange Membrane ◽  
Ion Exchange Membranes ◽  
Reverse Electrodialysis ◽  
Exchange Membrane

Salinity gradient power is a renewable, non-intermittent, and neutral carbon energy source. Reverse electrodialysis is one of the most efficient and mature techniques that can harvest this energy from natural estuaries produced by the mixture of seawater and river water. For this, the development of cheap and suitable ion-exchange membranes is crucial for a harvest profitability energy from salinity gradients. In this work, both anion-exchange membrane and cation-exchange membrane based on poly(epichlorohydrin) and polyvinyl chloride, respectively, were synthesized at a laboratory scale (255 c m 2) by way of a solvent evaporation technique. Anion-exchange membrane was surface modified with poly(ethylenimine) and glutaraldehyde, while cellulose acetate was used for the cation exchange membrane structural modification. Modified cation-exchange membrane showed an increase in surface hydrophilicity, ion transportation and permselectivity. Structural modification on the cation-exchange membrane was evidenced by scanning electron microscopy. For the modified anion exchange membrane, a decrease in swelling degree and an increase in both the ion exchange capacity and the fixed charge density suggests an improved performance over the unmodified membrane. Finally, the results obtained in both modified membranes suggest that an enhanced performance in blue energy generation can be expected from these membranes using the reverse electrodialysis technique.

scholarly journals Facile synthesis and properties of a cation exchange membrane with bifunctional groups prepared by pre-irradiation graft copolymerization

RSC Advances ◽  
2018 ◽  
Vol 8 (46) ◽  
pp. 25966-25973 ◽  
Author(s):  
Jianhua Zu ◽  
Fangdong Tang ◽  
Linfeng He ◽  
Lingxiao Fu
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Graft Copolymerization ◽  
Low Cost ◽  
Cation Exchange Membrane ◽  
Ion Exchange Membrane ◽  
Facile Synthesis ◽  
Exchange Membrane ◽  
Irradiation Graft

Low-cost and anti-degradation ion-exchange membrane named ETFE-g-poly(AA-co-SSS) with bifunctional groups prepared by the pre-irradiation grafting method.

scholarly journals Preparation of PVA-Based Hollow Fiber Ion-Exchange Membranes and Their Performance for Donnan Dialysis

Membranes ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 4
Author(s):  
Mitsuru Higa ◽  
Yuriko Kakihana ◽  
Takehiro Sugimoto ◽  
Kakuya Toyota
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Fiber Type ◽  
Outer Diameter ◽  
Ion Exchange Membranes ◽  
Donnan Dialysis ◽  
Exchange Membrane

Hollow fiber type cation-exchange (C-HF) membranes and hollow fiber type anion-exchange (A-HF) membranes were prepared from poly (vinyl alcohol) (PVA)-based copolymer with cation-exchange groups and by blending PVA and polycation, respectively, by a gel fiber spinning method. In order to control the water content of the hollow fiber membranes, the membranes were cross-linked physically by annealing, and then cross-linked chemically by using glutaraldehyde (GA) solutions at various GA concentrations. The outer diameter of C-HF and A-HF membranes were ca. 1000 μm and ca. 1500 μm, respectively, and the thickness of the membranes were ca. 170 μm and 290 μm, respectively. Permeation experiments were carried out in two Donnan dialysis systems, which included mixed 0.1 M NaCl and 0.1 M CaCl2/C-HF /3 × 10−4 M CaCl2 and mixed 0.1 M NaCl and 0.1 M NaNO3/A-HF/3 × 10−4 M NaNO3 to examine ionic perm selectivity of the membranes. In the Donnan dialysis experiments using C-HF membranes, uphill transport of the divalent cations occurred, and, in the case of A-HF membranes, uphill transport of NO3− ions occurred. C-HF and A-HF membranes had about half of the flux in the uphill transported ions and also about half of the selectivity between the uphill transport ions and driven ions in comparison with those of the commercial flat sheet cation-exchange membrane (Neosepta® CMX) and anion-exchange membrane (Neosepta® AMX). Yet, IEC of C-HF and A-HF membranes were about one fifth of CMX and less than half of AMX, respectively. Since hollow fiber membrane module will have higher packing density than a flat membrane stack, the hollow fiber type ion-exchange membranes (IEMs) prepared in this study will have a potential application to a Donnan dialysis process.

scholarly journals Enhancing Ion Transfer in Overlimiting Electrodialysis of Dilute Solutions by Modifying the Surface of Heterogeneous Ion-Exchange Membranes

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Natalia Pismenskaya ◽  
Nadezhda Melnik ◽  
Ekaterina Nevakshenova ◽  
Kseniya Nebavskaya ◽  
Victor Nikonenko
Keyword(s):  
Mass Transfer ◽  
Surface Layer ◽  
Ion Exchange ◽  
Cation Exchange ◽  
Water Splitting ◽  
Anion Exchange ◽  
Membrane Surface ◽  
Anion Exchange Membrane ◽  
Cation Exchange Membrane ◽  
Exchange Membrane

The desalination of dilute NaCl solutions with heterogeneous Russian commercial and modified ion-exchange membranes was studied in a laboratory cell imitating desalination channels of large-scale electrodialysers. The modification was made by casting a thin film of a Nafion-type material on the surface of cation-exchange membrane, and by processing with a strong polyelectrolyte the surface of anion-exchange membrane. It was shown that the modifications resulted in an increase of mass transfer coefficient and in a decrease in water splitting rate, both by up to 2 times. The effect of mass transfer growth is explained by higher surface hydrophobicity of the modified membrane that enhances electroconvection. The decrease in water splitting rate in the case of cation-exchange membrane is due to homogenization of its surface layer. In the case of anion-exchange membrane the effect is due to grafting of quaternary ammonium bases onto the original membrane surface layer. The suppression of water splitting favors development of electroconvection. In turn, intensive electroconvection contributes to deliver salt ions to membrane surface and thus reduces water splitting.

Penyediaan dan Pencirian Membran Pertukaran Kation dengan Resin untuk Proses Elektrodialisis

2012 ◽  
Author(s):  
Mahadevan. M. ◽  
Lay Pee Lin ◽  
Zainal Abidin M. Y. ◽  
Mohamad Roji Sarmidi
Keyword(s):  
Ion Exchange ◽  
Cation Exchange ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Ion Exchange Resin ◽  
Anion Exchange Membrane ◽  
Cation Exchange Membrane ◽  
Membrane Thickness ◽  
Anion Exchange Membranes ◽  
Exchange Membrane

Elektrodialisis merupakan suatu proses yang menggunakan perbezaan keupayaan elektrik sebagai daya penggerak yang menyebabkan pergerakan ion-ion dalam sesuatu elektronit. Membran yang digunakan dalam proses ini akan membenarkan sama ada cas-cas positif atau negatif sahaja melaluinya bergantung kepada kumpulan berfungsi yang terikat pada membran. Objektif projek penyelidikan ini adalah untuk menghasilkan membran pertukaran kation yang digunakan dalam proses elektrodialisis. Membran-membran pertukaran kation yang dihasilkan terbahagi kepada lima jenis, dan diberi nama sebagai BERL–30, 40, 50, 60, dan 70. Kelima-lima jenis membran ini berbeza dari segi kandungan resin yang berfungsi sebagai vektor pertukaran cas kation. Di samping penyediaan membran, penyelidikan ini juga meliputi aspek pencirian membran tersebut serta perbandingan dengan membran komersial. Kriteria yang dikaji adalah ketebalan membran, sifat kebolehtelapan membran, kapasiti pertukaran ion, kapasiti kepekatan ion kumpulan berfungsi, morfologi struktur membran, ujian kestabilan kimia dan kandungan air membran. Secara keseluruhannya, didapati peratus kandungan resin yang tinggi boleh meningkatkan kapasiti pertukaran ion, peratus kebolehtelapan membran serta kapasiti kepekatan ion kumpulan berfungsi. Antara membran yang dihasilkan, membran pertukaran kation jenis BERL–70 merupakan membran yang berpotensi dalam penggunaan proses elektrodialisis. Kata kunci: Membran pertukaran kation, polisulfona, resin pertukaran ion, ciri-ciri membran, elekrodialisis The objective of this work is to prepare an anion exchange membrane from polysulfone binder–ion exchange resin, which can be used in electrodialysis process. The cation exchange membranes were prepared by the solution casting method. The prepared anion exchange membranes are different from the conventional cation exchange membranes because its functional group is not derived from chlorosulfonic acid but from the absorption of anion exchange resins. The content of resins in each set of the prepared cation exchange membrane varied and were named as BERL–30, 40, 50, 60, and 70. In addition, the performance and behaviour of the prepared anion exchange membrane were evaluated and compared with the commercial cation exchange membranes. The physico-chemical properties of anion exchange membrane were determined by measuring the membrane thickness, permselectivity, and concentration of ion exchange capacity, chemical stability, water content, and scanning electron microscope (SEM). It was found that the increase in the quantity of resin (%) would increase the capacity of ion exchange, percentage of permselectivity, and capacity concentration of ion exchange group. The experimental results showed that cation exchange membrane has the potential to be used in electrodialysis process. Keywords: Cation exchange membrane, electrodialysis, polysulfone, ion exchange resin, membrane characterisation

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