Reassessment of adsorption–reduction mechanism of hexavalent chromium in attaining practicable mechanistic kinetic model

2016 ◽  
Vol 102 ◽  
pp. 98-105 ◽  
Author(s):  
Zhung-Gia Ng ◽  
Jun-Wei Lim ◽  
Hanita Daud ◽  
Si-Ling Ng ◽  
Mohammed J.K. Bashir
Keyword(s):  
Kinetic Model ◽  
Hexavalent Chromium ◽  
Reduction Mechanism ◽  
Adsorption Reduction

scholarly journals Mechanism and modeling of hexavalent chromium interaction with a typical black soil: the importance of the relationship between adsorption and reduction

RSC Advances ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 5582-5591 ◽  
Author(s):  
Jia Zhang ◽  
Huilin Yin ◽  
Samuel Barnie ◽  
Minghai Wei ◽  
Honghan Chen
Keyword(s):  
Kinetic Model ◽  
Hexavalent Chromium ◽  
Black Soil ◽  
Reduction Mechanism ◽  
Soil P ◽  
Adsorption Reduction ◽  
The Relationship

A novel two-step kinetic model was developed based on the proposed “adsorption–reduction” mechanism of Cr(vi) retention by a typical black soil.

scholarly journals Efficient removal of hexavalent chromium from water by an adsorption–reduction mechanism with sandwiched nanocomposites

RSC Advances ◽  
2018 ◽  
Vol 8 (27) ◽  
pp. 15087-15093 ◽  
Author(s):  
Weikang Liu ◽  
Liang Yang ◽  
Shihao Xu ◽  
Yao Chen ◽  
Bianhua Liu ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Reduction Mechanism ◽  
Efficient Removal ◽  
Chromium Ion ◽  
Adsorption Reduction

A sandwiched nanocomposite has been developed to remove hexavalent chromium ion Cr(vi) from water by an adsorption–reduction mechanism.

scholarly journals Recyclable functionalized polymer films for the efficient removal of hexavalent chromium from aqueous solutions

RSC Advances ◽  
2019 ◽  
Vol 9 (63) ◽  
pp. 36751-36757 ◽  
Author(s):  
Weikang Liu ◽  
Mei Wang ◽  
Zhigang Wen ◽  
Zhong Li ◽  
Liang Yang ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Composite Film ◽  
Hexavalent Chromium ◽  
Polymer Films ◽  
Reduction Mechanism ◽  
Efficient Removal ◽  
Chromium Ion ◽  
Adsorption Reduction

A PEI-PVA functionalized composite film has been developed to remove hexavalent chromium ion Cr(vi) from water by an adsorption–reduction mechanism.

Nano nickel embedded in N-doped CNTs-supported porous biochar for adsorption-reduction of hexavalent chromium

2021 ◽  
pp. 125693
Author(s):  
Danchen Zhu ◽  
Jingai Shao ◽  
Ziqing Li ◽  
Haiping Yang ◽  
Shihong Zhang ◽  
...  
Keyword(s):  
Hexavalent Chromium ◽  
Adsorption Reduction ◽  
Nano Nickel

An in situ IR study of the NOx adsorption/reduction mechanism on modified Y zeolites

2003 ◽  
Vol 5 (9) ◽  
pp. 1897-1905 ◽  
Author(s):  
Christian Sedlmair ◽  
Barbara Gil ◽  
Kulathuiyer Seshan ◽  
Andreas Jentys ◽  
Johannes A. Lercher
Keyword(s):  
Reduction Mechanism ◽  
Y Zeolites ◽  
In Situ Ir ◽  
Nox Adsorption ◽  
Adsorption Reduction ◽  
Ir Study

Characteristics and kinetics of hexavalent chromium reduction by gallic acid in aqueous solutions

2015 ◽  
Vol 71 (11) ◽  
pp. 1694-1700 ◽  
Author(s):  
ZiFang Chen ◽  
YongSheng Zhao ◽  
Qin Li
Keyword(s):  
Kinetic Model ◽  
Gallic Acid ◽  
Hexavalent Chromium ◽  
Ph Value ◽  
Order Kinetic ◽  
First Order ◽  
Molar Ratios ◽  
Wide Range ◽  
Order Kinetic Model ◽  
Pseudo First Order

Gallic acid (GA) is a naturally occurring plant polyphenol compound. Experiments were conducted to study the kinetics and effects of pH, temperature, irradiation, and initial hexavalent chromium (Cr(VI)) concentration on Cr(VI) reduction by GA. Results indicated that Cr(VI) could be reduced to chromium oxide (Cr(III)) with GA in a wide range of pH values from 2.0 to 8.5. The reaction followed a pseudo-first-order kinetic model with respect to Cr(VI) and GA in acid conditions (pH 2.0–5.0). However, the reaction did not follow the pseudo-first-order kinetic model at pH 6.5 and 8.5. Removal efficiencies and reaction rate constants of Cr(VI) significantly increased with decreasing pH value and increasing temperature. The effect of irradiation on Cr(VI) reduction increased with increasing pH, and irradiation improved the removal efficiency of Cr(VI) by 11.29% at pH 6.5. At pH 2.0, nearly all molar ratios of GA required for the reduction of Cr(VI) were 1:2 (±0.1) under different initial Cr(VI) concentrations; however, the molar ratios of GA required for the reduction of Cr(VI) were 1:1.29, 1:1.43, and 1:1.69, respectively, when the initial Cr(VI) concentrations were 10, 25, and 50 mg/L at pH 5.5.

scholarly journals Two-Dimensional Titanium Carbides (Ti3C2Tx) Functionalized by Poly(m-phenylenediamine) for Efficient Adsorption and Reduction of Hexavalent Chromium

2019 ◽  
Vol 17 (1) ◽  
pp. 167 ◽  
Author(s):  
Linfeng Jin ◽  
Liyuan Chai ◽  
Weichun Yang ◽  
Haiying Wang ◽  
Liyuan Zhang
Keyword(s):  
Surface Charge ◽  
Hexavalent Chromium ◽  
In Situ Polymerization ◽  
Interlayer Spacing ◽  
Layer By Layer ◽  
Negative Surface ◽  
Negative Surface Charge ◽  
Adsorption Reduction ◽  
Titanium Carbides

Titanium carbides (MXenes) are promising multifunctional materials. However, the negative surface charge and layer-by-layer restacking of MXenes severely restrict their application in the field of anionic pollutants, including in hexavalent chromium (Cr(VI)). Herein, Ti3C2Tx MXenes was functionalized through in situ polymerization and intercalation of poly(m-phenylenediamine) (PmPD), then Ti3C2Tx/PmPD composites were obtained. Delightedly, Ti3C2Tx/PmPD composites exhibited positive surface charge, expanded interlayer spacing, and enhanced hydrophobicity. Furthermore, the specific surface area of Ti3C2Tx/PmPD composite was five and 23 times that of Ti3C2Tx and PmPD, respectively. These advantages endowed Ti3C2Tx/PmPD composite with an excellent adsorption capacity of Cr(VI) (540.47 mg g−1), which was superior to PmPD (384.73 mg g−1), Ti3C2Tx MXene (137.45 mg g−1), and the reported MXene-based adsorbents. The Cr(VI) removal mechanism mainly involved electrostatic adsorption, reduction, and chelation interaction. This study developed a simple functionalization strategy, which would greatly explore the potential of MXenes in the field of anionic pollutants.

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