Natural zeolites as effective adsorbents in water and wastewater treatment

https://dr.ntu.edu.sg/bitstream/10356/96770/1/30.%20Application%20of%20Layered%20Double%20Hydroxides%20for%20Removal%20of%20Oxyanions.pdf

Application of layered double hydroxides for removal of oxyanions: A review

Fluoride removal from water by adsorption—A review

http://edge.rit.edu/content/P13418/public/Reference%20Documents/Fluoride%20Removal/Review%20of%20fluoride%20removal%20from%20drinking%20water.pdf

Review of fluoride removal from drinking water.

A review of emerging adsorbents for nitrate removal from water

The aim of this work is to present experimental results on the removal of nitrate by nitrate selective ion exchange resin, Purolite A 520E. The resin dose as the optimum condition for nitrate removal was determined. Adsorption isotherm has been modelled by Langmuir and Dubinin-Radushkevich (DR) equations. Nitrate removal by strong base anion exchange resin Purolite A 520E was also carried out with column method. The existence of chloride and sulfate ions influenced the breakthrough capacity of the resin for nitrate. Nitrate was also effectively removed from the ground water. The nitrate sorbed on Purolite A 520E was quantitatively eluted with 0.6 M NaCl.

Removal of nitrate from aqueous solution by nitrate selective ion exchange resins

Separation of fluoride from aqueous solution by electrodialysis: effect of process parameters and other ionic species.

Boron removal from wastewaters of geothermal plant was studied using N-glucamine type chelating resins so-called Diaion CRB 01, Diaion CRB 02, Purolite S 108. The batch-mode sorption studies was performed to obtain the optimum amount of resins for boron removal from geothermal wastewater. The boron on the resin was quantitatively eluted with 5% H2SO4. A column-mode study was performed using weak base ion exchange resin Diaion WA 30 for the separation of boron from H2SO4 solution.

Removal and recovery of boron from geothermal wastewater by selective ion exchange resins. I. Laboratory tests

In this study, the ion exchange of metal ions (Al3+, La3+ and ZrO2+) on modified zeolites was carried out using batch method. Fluoride removal from water using Al3+‐, La3+‐ and ZrO2+‐ exchanged zeolite was subsequently investigated to evaluate the fluoride sorption characteristics of the sorbents. Natural zeolite samples (<45 µm) were pre‐conditioned with HNO3 solution (ZEO‐1), NaNO3 solution (ZEO‐2), and deionized water (ZEO‐3) before loading Al3+, La3+, and ZrO2+ on zeolite. ZEO‐1 type zeolite had a higher capacity than ZEO‐2 and ZEO‐3 type zeolites. Metal exchange capacities are 0.233, 0.089, 0.090 mmol/g for ZrO2+‐, La3+‐, and Al3+‐ exchanged zeolite (ZEO‐1), respectively. Equilibrium isotherms fitted well to Langmuir and Freundlich models. Percent removal of fluoride from aqueous solution containing 2.5 mg F/L was 94% using metal loaded zeolite (ZEO‐1 type) at an adsorbent concentration of 6.00 g/L.

Removal of fluoride from water by metal ions (Al3+, La3+ and ZrO2+) loaded natural zeolite

To generate a new sorbent with high boron adsorption capacity, we synthesized monodisperse-porous poly(vinylbenzyl chloride-co-divinylbenzene), poly(VBC-co-DVB), beads 8.5 μm in size by a new “modified seeded polymerization” technique. By using their chloromethyl functionality, the beads were derivatized by a simple, direct reaction with a boron-selective ligand, N-methyl-D-glucamine (NMDG). The selection of poly(VBC-co-DVB) beads as a starting material allowed to obtain high boron sensitive-ligand density on the beads depending on their high chloromethyl content. In the batch adsorption runs performed using NMDG-attached poly(VBC-co-DVB) beads as sorbent, boron removal was efficiently performed in a wide pH range between 4 and 11. Quantitative boron removal was observed with the sorbent concentration of 4 g/L. In the same runs, plateau value of equilibrium adsorption isotherm was obtained as 14 mg boron/g beads. Relatively higher boron adsorption was explained by high ligand density and high specific surface area of the sorbent. Boron adsorption isotherms were analyzed using Langmuir and Freundlich models. In the kinetic runs performed for boron removal, the equilibrium was attained within 10 min at a value of 98%. The fast kinetic behavior was explained by the smaller particle size and enhanced porosity of the new sorbent. Infinite solution volume model and unreacted core model were used to evaluate boron adsorption onto the NMDG-attached poly(VBC-co-DVB) beads. The results indicated that the adsorption process is controlled by the particle-diffusion step. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Saba Samatya

Papers

Removal of nitrate from aqueous solution by nitrate selective ion exchange resins

Separation of fluoride from aqueous solution by electrodialysis: effect of process parameters and other ionic species.

Removal and recovery of boron from geothermal wastewater by selective ion exchange resins. I. Laboratory tests

Removal of fluoride from water by metal ions (Al3+, La3+ and ZrO2+) loaded natural zeolite

Monodisperse-porous N-methyl-D-glucamine functionalized poly(vinylbenzyl chloride-co-divinylbenzene) beads as boron selective sorbent