Deboronation of geothermal water using N-methyl-D-glucamine based chelating resins and a novel fiber adsorbent: batch and column studies

Abstract

BACKGROUND Development of new selective chelating resins and fibers with large capacity, high selectivity and high sorption rate has received great interest particularly for boron removal from water. In this study, batch and column mode tests were performed to evaluate the abilities of boron selective ion exchange resins, Diaion CRB 02 and Diaion CRB 05, as well as a novel chelating fiber Chelest Fiber GRY‐HW for boron removal from geothermal water containing boron concentration of 10–11 mg B L−1. RESULTS Optimum adsorbent amounts were found to be 4.0 g resin L−1 geothermal water for Diaion CRB 02, 6.0 g resin L−1 geothermal water for Diaion CRB 05 and 8.0 g fiber L−1 geothermal water for Chelest Fiber GRY‐HW. The adsorbents exhibited promising adsorption capacity and their adsorption data for boron agreed well with both Langmuir and Freundlich models. It was found that the sorption kinetics was influenced by particle size of the adsorbents. The rate‐determining step for boron separation from geothermal water was found to be particle diffusion. According to the results of the column‐mode study, Diaion CRB 05 had a breakthrough capacity of 3.74 mg B mL−1 resin, whereas Chelest Fiber GRY‐HW and Diaion CRB 02 had a breakthrough capacity of 2.16 mg B mL−1 fiber and 1.66 mg B mL−1 resin, respectively. CONCLUSIONS These results showed that boron selective chelating resins along with novel chelating fiber could be employed as efficient adsorbents to decrease boron concentration in geothermal water below the permissible level for irrigation water (<1.0 mg L−1). © 2017 Society of Chemical Industry

Packed bed column dynamic study for boron removal from geothermal brine by a chelating fiber and breakthrough curve analysis by using mathematical models

“…In our previous study conducted using a batch mode of operation, the total adsorption capacity of this fiber adsorbent were found to be 18.52 mg/g-fiber due to testing it with spiked geothermal brine having ca. 100 mg B/L as the highest initial boron concentration [38]. So, the initial concentration has an important effect on adsorption capacity.…”

“…It has also been developed recently that this fibrous adsorbent found to possess a faster adsorption kinetic for boron than that of boron selective chelating ion exchange resins [35]. So far, we have compared the performance of Chelest Fiber with ion exchange resins, Diaion CRB 02 and CRB 05, by batch and column mode tests for removal of boron from geothermal brine [38]. Moreover, Ting et al [39] evaluated the adsorption of boron from model solutions on new radiation grafted fibrous adsorbent containing N-methyl-D-glucamine [39].…”

Nanoscale Surface Compositions and Structures Influence Boron Adsorption Properties of Anion Exchange Resins

“…Highly cross-linked polymers with surface-grafted acidic or basic functional groups are used to adsorb and exchange counterions from aqueous and organic solutions. The ion-exchange properties of such polymer resins can be adjusted by incorporating suitable surface functional groups for different technological applications including desalination, , chromatography-based separation and purification, and catalysis. − For example, naturally occurring chitosan polymers or synthetic styrene-divinylbenzene copolymers grafted with surface COO – or SO 3 – functional groups have been shown to exchange cations or anions − when surface-grafted with sorbitol, mannitol, and N -methyl- d -glucamine (NMDG) groups. , Ion-exchange resins have also been used to catalyze reactions, such as alkylation, isomerization, oligomerization, acylation, esterification, and nitration − and have long been recognized for their environmental remediation applications. ,,,, Of particular interest, ion-exchange resins have been used to reduce boron concentration levels in soil, surface, and wastewaters, including as part of decontamination efforts in Fukushima, Japan. Boron-containing materials are also used extensively in power generation applications and in the production and processing of diverse engineering materials, such as glasses, ceramics, fertilizers, detergents, catalysts, and semiconductors. − Despite their high technological importance, much remains unknown about the relationships between the compositions, structures, and properties of boron-containing materials, especially those involving dilute surface species.…”

“…In particular, many commercial boron-adsorption ion-exchange resins are based on polymers grafted with NMDG functional groups. ,,, For such materials, the hydroxyl groups of the NMDG moieties exhibit high binding affinity toward borate anions. , This imparts the NMDG-functionalized polymers with high boron adsorption capacities and correspondingly favorable separation efficacies, compared to other approaches such as reverse osmosis, , electrodialysis, polymer-enhanced ultrafiltration, and sorption, , which tend to rely on weak noncovalent interactions. The reversible interactions of borate anions with hydroxyl groups have been exploited in the development of boron sorbents based on nitrogen-doped graphene oxide surface-grafted with hydroxyl groups, diol-functionalized silica particles, and Nylon-6 fibrils grafted with NMDG moieties .…”

“…4−6 For example, naturally occurring chitosan polymers or synthetic styrene-divinylbenzene copolymers grafted with surface COO − or SO 3 − functional groups have been shown to exchange cations 1 or anions 7−9 when surface-grafted with sorbitol, 10 mannitol, 11 and N-methyl-D-glucamine (NMDG) groups. 12,13 Ion-exchange resins have also been used to catalyze reactions, such as alkylation, isomerization, oligomerization, acylation, esterification, and nitration 14−16 and have long been recognized for their environmental remediation applications. 8,12,13,17,18 Of particular interest, ion-exchange resins have been used to reduce boron concentration levels in soil, surface, and wastewaters, including as part of decontamination efforts in Fukushima, Japan.…”