Selectivity reversal and dimerization of chromate in the exchanger Amberlite IRA-400

Mustafa, S.; Bashir, H; Rehana, N.; Akhtar, Naeem

doi:10.1016/s1381-5148(97)00079-5

Cited by 30 publications

(18 citation statements)

References 8 publications

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“…The anion exchangers were equilibrated for 24 h on a shaker; from preliminary measurements the contact time of 24 h was determined to be sufficient for reaching equilibrium. Similar experiments, performed on the commercial strong base anion exchanger Amberlite IR-400 (Rohm and Haas, Philadelphia, PA), showed that the time to achieve equilibrium was only 6 h. 20 After contact, the beads were filtered and the filtrate was analyzed for chromate ions by a photocolorimetric method using diphenylcarbazide, a filter of 540 nm, and standard solutions of 0.1-0.8 mg Cr/L concentrations.…”

Section: Methodsmentioning

confidence: 87%

“…Also, as the concentration of aqueous phase electrolyte is increased, the counterions of lower valence become more selective compared to the counterions of higher valence. 20 In the case of the RCl resin form, the monovalent counterions Cl Ϫ become more selective compared to divalent CrO 4 2Ϫ anions and the Cr(VI)-retention capacity of anionites decreased. In the case of the R 2 SO 4 resin form, both SO 4 2Ϫ and CrO 4 2Ϫ ions are divalent and CrO 4 2Ϫ ions are selectively retained and Cr(VI)-retention capacity of the anionite increases.…”

mentioning

confidence: 96%

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Sorption equilibrium of Cr(VI) ions by strong base anion exchangers with pyridine structures

Neagu¹,

Untea

Tudorache

et al. 2004

J of Applied Polymer Sci

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Chromate sorption on pyridine strong base anion exchangers with different functional groups (methyl, ethyl, and butyl groups), at the quaternary nitrogen atoms, was studied as a function of various initial concentrations (100 -1500 mg Cr/L) and counterion type. The studied resins in the Cl Ϫ[ form have higher Cr(VI)-retention capacities than those in the SO 4 2Ϫ form. The pyridine strong base anion exchangers showed a selectivity reversal for the sulfate and chromate anions compared to that of the commercial resins. The alkyl substituent length of the quaternary nitrogen atoms exerted a substantial influence on the Cr(VI)-retention capacity values for the resins in the Cl Ϫ form; the chromate anions preferred resins with methyl functional groups, that is, resins with a greater hydrophilic structure. For the resins in the SO 4 2Ϫ form the length of the substituent at the quaternary nitrogen atom had only a negligible influence on their Cr(VI)-retention values.

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Section: Methodsmentioning

confidence: 87%

mentioning

confidence: 96%

Sorption equilibrium of Cr(VI) ions by strong base anion exchangers with pyridine structures

Neagu¹,

Untea

Tudorache

et al. 2004

J of Applied Polymer Sci

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“…Like many other metallic species, chromium has variety of applications in leather tanning, explosives, ceramics, paint pigments, photography, and wood preservation. These industrial processes discharge large quantities of chromium into the environment, which has significant undesirable biological and ecological effects (Herrmann 1994;Mustafa et al 1997;Tadesse et al 2006).…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Chromium Ion Removal from Tannery Wastes Using Amberlite IRA-400 Cl− and its Hybrids

Mustafa

Ahmad

Akhtar

et al. 2009

Water Air Soil Pollut

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A strong base anion exchange resin Amberlite IRA-400 Cl − and its hybrids with Mn(OH) 2 and Cu(OH) 2 are used for the removal of chromium from the synthetic spent tannery bath. The recovery is examined by varying the experimental conditions, viz., resin dosage, stirring speed, and temperature. The rate of chromium removal by Amberlite IRA-400 Cl − increased almost four times when the resin dosage was increased from 0.2 to 1.0 g. Furthermore, the rate of chromium sorption almost doubled when the stirring speed was increased from 100 to 1,000 rpm, suggesting that the sorption is a diffusionally controlled process. The chromium removal capacity also increased with the rise of temperature, showing the endothermic nature of the process. The results are explained with the help of film diffusion, particle diffusion, and Lagergren pseudo-first-order kinetic models. The kinetics results of the Amberlite IRA-400 Cl − are compared with its hybrid anion exchange resins IRA-400 Mn(OH) 2 and IRA-400 Cu(OH) 2 . It is found that the hybrid ion exchangers have greater removal ability and fast kinetics as compared to the parent exchanger.

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“…The metal ion may thus enter drinking water supply systems via the corrosion inhibitors used in water pipes and containers. It is therefore of major concern to understand the nature of the chromium anion and its effective removal from natural aquatic systems (Sahayam et al 1998;Mustafa et al 1997).…”

Section: Introductionmentioning

confidence: 99%

“…The interest in chromium(VI) is not only governed by its toxicity but also due to the fact that very little attention appears to have been given in the literature to structurally complex oxyanions (Wu et al 2000;Mustafa et al 2000) such as chromates which may involve different ionic species depending upon the experimental conditions. Recent interest in anion-exchange studies of complex anions such as chromates, sulphates and phosphates (Wu et al 2000;Sahayam et al 1998;Mustafa et al 1989) has arisen because of their practical importance in the fields of water pollution, fertilizers, metal protection, detergents, etc.…”

Section: Introductionmentioning

confidence: 99%

Chromate Anion Adsorption on Iron Hydroxide

Mustafa

Jamal

Akhtar

et al. 2001

Adsorption Science & Technology

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Chromate anion adsorption on iron hydroxide was studied as a function of pH (3-9) and temperature (20-40ºC). The adsorption of chromate anion was found to decrease with increasing pH and increase with increasing temperature. The data were explained with the help of the Kurbatov and modified Langmuir equations. The small effect of temperature indicated that chromate anion adsorption on iron hydroxide occurred through a mechanism involving outersurface sphere complexation.

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Selectivity reversal and dimerization of chromate in the exchanger Amberlite IRA-400

Cited by 30 publications

References 8 publications

Sorption equilibrium of Cr(VI) ions by strong base anion exchangers with pyridine structures

Sorption equilibrium of Cr(VI) ions by strong base anion exchangers with pyridine structures

Kinetics of Chromium Ion Removal from Tannery Wastes Using Amberlite IRA-400 Cl− and its Hybrids

Chromate Anion Adsorption on Iron Hydroxide

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