scholarly journals Bifunctional Ionic Covalent Organic Networks for Enhanced Simultaneous Removal of Chromium(VI) and Arsenic(V) Oxoanions via Synergetic Ion Exchange and Redox Process (Small 46/2021)

Small ◽  
2021 ◽  
Vol 17 (46) ◽  
pp. 2170241
Author(s):  
Ping Li ◽  
Joshua T. Damron ◽  
Gabriel M. Veith ◽  
Vyacheslav S. Bryantsev ◽  
Shannon M. Mahurin ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Redox Process ◽  
Simultaneous Removal ◽  
Chromium Vi ◽  
Organic Networks

scholarly journals Amberlite IRC-718 ion chelating resin extraction of hazardous metal Cr (VI) from aqueous solutions: equilibrium and theoretical modeling

2021 ◽  
Author(s):  
Abdelhamid Addala ◽  
Moussa Boudiaf ◽  
Maria Elektorowicz ◽  
Embarek Bentouhami ◽  
Yacine Bengeurba
Keyword(s):  
Ion Exchange ◽  
Aqueous Solutions ◽  
Exchange Process ◽  
Ion Exchange Resin ◽  
Exchange Capacity ◽  
Chelating Resin ◽  
Exchange Potential ◽  
Chromium Vi ◽  
Ion Exchange Process ◽  
Hazardous Metal

Abstract Under varied conditions, the IRC 718 ion-exchange resin is used to extract chromium (VI) ions from aqueous solutions. On chromium (VI) removal effectiveness, the effects of adsorption dosage, contact time, beginning metal concentration, and pH were examined. The batch ion exchange process reached equilibrium after around 90 minutes of interaction. With an initial chromium (VI) concentration of 0.5 mg/dm3, the pH-dependent ion-exchange mechanism revealed maximal removal in the pH 2.0–10 range . The adsorption mechanism occurs between Cr(VI) determined as the electron acceptor, and IRC 718 determined as the electron donor. The equilibrium ion-exchange potential and ion transfer quantities for Amberlite IRC 718 were calculated using the Langmuir adsorption isotherm model. The overall ion exchange capacity of the resin was determined to be 187.72 mg of chromium (VI)/g of resin at an ideal pH of 6.0.

Adsorption and ion exchange of some groundwater anion contaminants in an amine modified coconut coir

1997 ◽  
Vol 35 (7) ◽  
pp. 89-95 ◽  
Author(s):  
Aloysius U. Baes ◽  
Tetsuji Okuda ◽  
Wataru Nishijima ◽  
Eiji Shoto ◽  
Mitsumasa Okada
Keyword(s):  
Ion Exchange ◽  
Low Cost ◽  
Exchange Capacity ◽  
Batch Adsorption ◽  
Ion Exchange Capacity ◽  
Strong Base ◽  
Chromium Vi ◽  
Freundlich Equation ◽  
Adsorption Data ◽  
Coconut Coir

The adsorption of nitrate, chromium (VI), arsenic (V) and selenium (VI) anions in an amine modified coconut coir (MCC-AE : with secondary and tertiary amine functionality) were studied to determine the capability of this easily prepared and low-cost material in removing typical groundwater anion contaminants. Batch adsorption-ion exchange experiments were conducted using 200 mg MCC-AE, initially containing chloride as the resident anion, and 50 ml of different anion-containing water of varying concentrations. It is presumed, at this low pH, that only SeO42− remained as a divalent anion, while monovalent species H2AsO4− and HCrO4− predominated in their respective exchanging ion solutions. The adsorption data were fitted using the Freundlich equation and maximum adsorption for each anion was estimated using their respective Freundlich equation constants. MCC-AE exhibited preference for divalent Cr (VI) and Se (VI) anions compared with the Cl− resident ion. Maximum As (V) adsorption was 0.086 mmol/g, while maximum adsorption of Cr (VI), NO3− and Se (VI) anions was 0.327 mmol/g, 0.459 mmol/g, and 0.222 mmol/g, respectively. The ion exchange capacity of MCC-AE is estimated, based on its exchange capacity for nitrate, to be within 0.46 mmol of positive charges per gram. Similar adsorption experiments were conducted for comparison using commercial chloride-form Amberlite IRA-900 strong base (quaternary amine functionality) anion exchanger, with an exchange capacity of 4.2 meq/g. Maximum adsorption of the different ions in IRA-900 was about 3 times higher for NO3−, 9 times higher for Se (VI), 10 times higher for As (V) and 9 times higher for Cr (VI), than that in MCC-AE. Differences in the ion exchange behavior of MCC-AE and IRA-900 were probably due to the different amine functionalities in the two exchangers. The results suggest that MCC-AE may be used as a low-cost alternative adsorbent/ion exchanger for treatment of anion contaminants in groundwater.

ESCA and Vibrational Spectroscopy of Alkali Cation Exchanged Manganic Acids with the 2×2 type Tunnel Structure Synthesized via Different Chemical Routes

2000 ◽  
Vol 658 ◽  
Author(s):  
Masamichi Tsuji ◽  
Hirofumi Kanoh ◽  
Kenta Ooi
Keyword(s):  
Ion Exchange ◽  
Vibrational Spectroscopy ◽  
Mixed Valence ◽  
Redox Process ◽  
Alkali Cation ◽  
Exchange Mechanism ◽  
Uptake Mechanism ◽  
Alkali Cations ◽  
Xrd Patterns ◽  
Mixed Valence Compounds

ABSTRACTManganese dioxides have received much attention over the last two decades as ion exchangers. Actually these are typically mixed-valence compounds and the terminology of ‘dioxide’ is not appropriate. The mechanisms for their variety of chemical reactivities are still open for study. On the cation uptake mechanism there are strong claims that a redox process is involved in cation uptakes by manganic acids synthesized by substituting H+ for alkali cations incorporated in ‘hydrous manganese dioxides’. The present work was carried out to physically demonstrate the alkali cation exchange mechanism on tunnel-structured manganic acids and to study the ion exchange with lattice vibrational spectroscopy. Manganic acids were prepared through the redox process using KMnO4 and MnSO4, and thermal decomposition of (CH3)3COK and MnCO3 at 530°C. ESCA spectra of their alkali cation exchanged forms indicated no evidence of redox process and supported the ion exchange mechanism on these materials. Their infrared absorption spectra strongly depended on their preparation routes and are closely related to their ion-exchange selectivity of each material. Thus, the vibrational spectra of manganic acids take an important role as a synthesis index together with XRD patterns.

Electrically Switched Ion Exchange Based on Polypyrrole and Carbon Nanotube Nanocomposite for the Removal of Chromium(VI) from Aqueous Solution

2018 ◽  
Vol 57 (2) ◽  
pp. 768-774 ◽  
Author(s):  
Jianyu Xing ◽  
Chengzhou Zhu ◽  
Indranil Chowdhury ◽  
Yuhao Tian ◽  
Dan Du ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Carbon Nanotube ◽  
Ion Exchange ◽  
Chromium Vi

scholarly journals Chromium(VI) Removal from Aqueous Solution using Acrylic Ion Exchange Fiber

2017 ◽  
Vol 39 (3) ◽  
pp. 112-117 ◽  
Author(s):  
Aram Nam ◽  
Jeong-Ann Park ◽  
Taegu Do ◽  
Jae-Woo Choi ◽  
Ungsu Choi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Ion Exchange ◽  
Chromium Vi ◽  
Ion Exchange Fiber

Enhanced Photoreduction of Chromium(VI) Intercalated Ion Exchange in BiOBr0.75I0.25 Layers Structure by Bulk Charge Transfer

2018 ◽  
Vol 7 (2) ◽  
pp. 2429-2436 ◽  
Author(s):  
Tong Li ◽  
Gong Zhang ◽  
Huachun Lan ◽  
Huijuan Liu ◽  
Jiuhui Qu
Keyword(s):  
Charge Transfer ◽  
Ion Exchange ◽  
Chromium Vi ◽  
Bulk Charge
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