scholarly journals Nitrate-Selective Anion Exchange Membranes Prepared using Discarded Reverse Osmosis Membranes as Support

Membranes ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 377
Author(s):  
Amaia Lejarazu-Larrañaga ◽  
Juan Manuel Ortiz ◽  
Serena Molina ◽  
Yan Zhao ◽  
Eloy García-Calvo
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Reverse Osmosis ◽  
Current Density ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Transport Numbers ◽  
Anion Exchange Membranes ◽  
Filtration Membrane ◽  
Reverse Osmosis Membranes

The present work shows a methodology for the preparation of membranes with a high affinity for nitrates. For this purpose, a polymeric mixture containing an anion exchange resin was extended on a recycled pressure filtration membrane used as mechanical support. Different ion exchange resins were tested. The influence in ion fractionation of (i) the type of ion exchange resin, (ii) the use of a recycled membrane as support and (iii) the operating current density during the separation process were studied. Results revealed that the employed anion exchange resin could tune up the transport numbers of the anions in the membrane and enhance the transport of nitrates over sulfates. The use of the recycled filtration membrane as support further increased the transport of nitrates in detriment of sulfates in nitrate-selective membranes. Moreover, it considerably improved the mechanical stability of the membranes. Lowering the operational current density also boosted ion fractionation. In addition, the use of recycled membranes as support in membrane preparation is presented as an alternative management route of discarded reverse osmosis membranes, coupling with the challenging management of waste generated by the desalination industry. These membranes could be used for nitrate recovery from wastewater or for nitrate separation from groundwater.

scholarly journals Transport Characteristics of CJMAED™ Homogeneous Anion Exchange Membranes in Sodium Chloride and Sodium Sulfate Solutions

2021 ◽  
Vol 22 (3) ◽  
pp. 1415
Author(s):  
Veronika Sarapulova ◽  
Natalia Pismenskaya ◽  
Valentina Titorova ◽  
Mikhail Sharafan ◽  
Yaoming Wang ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Volume Fraction ◽  
Exchange Capacity ◽  
Polymer Materials ◽  
Transport Numbers ◽  
Anion Exchange Membranes ◽  
Microheterogeneous Model ◽  
Pass Through ◽  
Pes Membrane

The interplay between the ion exchange capacity, water content and concentration dependences of conductivity, diffusion permeability, and counterion transport numbers (counterion permselectivity) of CJMA-3, CJMA-6 and CJMA-7 (Hefei Chemjoy Polymer Materials Co. Ltd., China) anion-exchange membranes (AEMs) is analyzed using the application of the microheterogeneous model to experimental data. The structure–properties relationship for these membranes is examined when they are bathed by NaCl and Na2SO4 solutions. These results are compared with the characteristics of the well-studied homogenous Neosepta AMX (ASTOM Corporation, Japan) and heterogeneous AMH-PES (Mega a.s., Czech Republic) anion-exchange membranes. It is found that the CJMA-6 membrane has the highest counterion permselectivity (chlorides, sulfates) among the CJMAED series membranes, very close to that of the AMX membrane. The CJMA-3 membrane has the transport characteristics close to the AMH-PES membrane. The CJMA-7 membrane has the lowest exchange capacity and the highest volume fraction of the intergel spaces filled with an equilibrium electroneutral solution. These properties predetermine the lowest counterion transport number in CJMA-7 among other investigated AEMs, which nevertheless does not fall below 0.87 even in 1.0 eq L−1 solutions of NaCl or Na2SO4. One of the reasons for the decrease in the permselectivity of CJMAED membranes is the extended macropores, which are localized at the ion-exchange material/reinforcing cloth boundaries. In relatively concentrated solutions, the electric current prefers to pass through these well-conductive but nonselective macropores rather than the highly selective but low-conductive elements of the gel phase. It is shown that the counterion permselectivity of the CJMA-7 membrane can be significantly improved by coating its surface with a dense homogeneous ion-exchange film.

scholarly journals Boron Removal from Aqueous Solutions by Strong Base Anion-exchange Resin Batch and Column Experiments

2021 ◽  
Author(s):  
György Pátzay ◽  
József Dobor ◽  
Emil Csonka ◽  
Gábor Lozsi ◽  
Ferenc Feil
Keyword(s):  
Ion Exchange ◽  
Acid Solution ◽  
Boric Acid ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Free Water ◽  
Sulfate Solution ◽  
Boric Acid Solution ◽  
Strong Base

Borate ion exchange capacity of Purolite NRW600 strong base anion resin in hydroxide form and mixed bed NRW600+NRW100 ion exchange was investigated with static experiments. Anion exchange resin was saturated with 0.1–45 g/dm3 concentration boric acid solution in a static mixer at 20, 30, 40 and 50 °C at 150 rpm for 24 hours. Remaining borate content of saturation solutions was deter-mined with ion chromatography and ICP-OES. The amount of fixed borate as borate anions increased with the saturation borate concentration as well as in case of simple anion exchange as in case of mixed bed.Column sorption-elution study was carried out by using strong base anion exchange resins (Purolite NRW600 and Amberlite IRN78). Resins in hydroxide and in chloride forms were saturated in column with 5–40 g/dm3 boric acid solution in excess. The resin was then eluted with 200 cm3 salt free water with 5 cm3/min at 25 °C and then eluted by 1 mol/dm3 sodium-sulfate solution with 5 cm3/min. The effluent was collected and analyzed for borate content by titrimetric method. In chloride form the resin adsorbed and released much less borate. Effective borate and polyborate sorption needs hydroxide ions in resin phase.

Separation of Manganese, Cobalt, Copper, Zinc, and Magnesium By Using an Anion Exchange Resin

1967 ◽  
Vol 50 (4) ◽  
pp. 783-786
Author(s):  
Eugene A Breatjlt
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Ion Exchange Resin ◽  
Acid Solutions ◽  
Resin Column ◽  
Hydrochloric Acid Solutions ◽  
Copper Zinc ◽  
Resin Separation

Abstract The metals Mn, Mg, Co, Cu, and Zn were separated by using an anion exchange resin column and progressively less concentrated IIC1 solution as eluting agent. The position of Mg on an anion exchange resin, not previously reported in the literature, was determined. It has been shown that by using two different ion exchange resin columns, simple hydrochloric acid solutions as eluants, and polarographic or flame photometric determinations, 12 metals can be separately estimated in an aqueous solution containing about 100 /μg of each. It is recommended that the study of ion exchange resin separation of metals found in plants be continued.

scholarly journals Multifaceted ion exchange resin-supported hydrogen fluoride: a path to flow hydrofluorination

2019 ◽  
Vol 21 (9) ◽  
pp. 2224-2228 ◽  
Author(s):  
Zhichao Lu ◽  
Bhvandip S. Bajwa ◽  
Okoromoba E. Otome ◽  
Gerald B. Hammond ◽  
Bo Xu
Keyword(s):  
Ion Exchange ◽  
Anion Exchange ◽  
Hydrogen Fluoride ◽  
Exchange Resin ◽  
Anion Exchange Resin ◽  
Ion Exchange Resin ◽  
Anhydrous Hydrogen Fluoride

A solid anhydrous hydrogen fluoride equivalent was prepared by mixing HF gas with an inexpensive anion exchange resin (A26-HF, HF content 30% wt/wt).

Effects of pH and uranium concentration on the removal of uranium from drinking water by ion exchange

2000 ◽  
Vol 88 (12) ◽  
Author(s):  
K. Vaaramaa ◽  
Satu Pulli ◽  
Jukka Lehto
Keyword(s):  
Drinking Water ◽  
Ion Exchange ◽  
Anion Exchange ◽  
Exchange Resin ◽  
Uranium Concentration ◽  
Anion Exchange Resin ◽  
Column Experiments ◽  
Strong Base ◽  
Ph Values ◽  
Effects Of Ph

Effects of pH in the range of 5 to 8 and uranium concentration in the range of 0.02 mg/l to 25 mg/l on the removal of uranium with a strong base anion exchange resin (SBA) and a chelating aminophosphonate resin were studied. The results of the batch and column mode experiments clearly showed that the aminophosphonate resin was an efficient exchanger for the removal of uranium at pH values close to 5 and the SBA resin at higher pH values. In the column experiments, where altogether 2000 bed volumes of drinking water simulant were processed with these exchangers, the uptake of uranium was as high as 99.8% by the aminophosphonate resin at pH 5 and 99.7% by the SBA resin at pH 8.

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