Sorption of divalent metal ions on CrPO4

Mustafa, S.; Murtaza, Shahzad; Naeem, A.; Farina, K.

doi:10.1016/j.jcis.2004.09.049

Cited by 27 publications

(10 citation statements)

References 21 publications

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“…No Cr(OH)3 phase was identified in SD(12×), indicating that the reduction product of Cr(VI) by Na2S2O4 was amorphous, which agrees well with previous studies (Istok et al, 1999;Namgung et al, 2014;Rai et al, 2002;Su and Ludwig, 2005;Xu et al, 2004). The addition of Na3PO4, either through OSP or TSP, resulted in the formation of crystalline chromium phosphate hexahydrate (CrPO4·6H2O) which is more stable and insoluble than amorphous Cr(OH)3 (Gomm et al, 2007;Mustafa et al, 2005), leading to the lower TCLP Cr than observed for SD(12×). The results of XRD analyses therefore confirmed that the addition of Na3PO4 immobilized Cr(III) in COPRs through the formation of crystalline CrPO4·6H2O.…”

Section: X-ray Diffraction Analysessupporting

confidence: 89%

“…in the presence of strong oxidants such as manganese oxides), Cr(OH)3 could be re-oxidized to Cr(VI), and subsequently rereleased into the environment, impacting the long-term effectiveness of the remediatio n (Dhal et al, 2013). Research by Mustafa et al (2005) and Gomm et al (2007) illustrates however that the addition of phosphate species to Cr(III) (present as the trivale nt chromium ion or chromium hydroxides) resulted in formation of highly stable and insoluble Cr phosphate minerals under ambient conditions. Therefore, the addition of phosphate minerals could be expected to further transform Cr(III) into phosphatic mineral forms, making the reduction products more stable, less extractable and less toxic.…”

Section: Introductionmentioning

confidence: 99%

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Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism

Cundy

Feng

et al. 2017

Journal of Environmental Management

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Large amounts of chromite ore processing residue (COPR) wastes have been deposited in many countries worldwide, generating significant contamination issues from the highly mobile and toxic hexavalent chromium species (Cr(VI)). In this study, sodium dithionite (Na2S2O4) was used to reduce Cr(VI) to Cr(III) in COPR containing high available Fe, and then sodium phosphate (Na3PO4) was utilized to further immobilize Cr(III), via a two-step procedure (TSP). Remediation and immobilization processes and mechanisms were systematically investigated using batch experiments, sequential extraction studies, X-ray diffraction (XRD) and X-ray Photoelectron Spectroscopy (XPS). Results showed that Na2S2O4 effectively reduced Cr(VI) to Cr(III), catalyzed by Fe(III). The subsequent addition of Na3PO4 further immobilized Cr(III) by the formation of crystalline CrPO4·6H2O. However, addition of Na3PO4 simultaneo us ly with Na2S2O4 (via a one-step procedure, OSP) impeded Cr(VI) reduction due to the competitive reaction of Na3PO4 and Na2S2O4 with Fe(III). Thus, the remediatio n efficiency of the TSP was much higher than the corresponding OSP. Using an optimal dosage in the two-step procedure (Na2S2O4 at a dosage of 12× the stoichiome tr ic requirement for 15 days, and then Na3PO4 in a molar ratio (i.e. Na3PO4 : initial Cr(VI)) of 4:1 for another 15 days), the total dissolved Cr in the leachate determined via Toxicity Characteristic Leaching Procedure (TCLP Cr) testing of our samples was reduced to 3.8 mg/L (from an initial TCLP Cr of 112.2 mg/L, i.e. at >96% efficiency).

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Section: X-ray Diffraction Analysessupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism

Cundy

Feng

et al. 2017

Journal of Environmental Management

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“…As is evident from Fig. 7, the experimental data fitted to the linear form of the Langmuir equation expressed in the form [19,20].…”

Section: Equilibrium Studiesmentioning

confidence: 73%

Chromium (III) removal by weak acid exchanger Amberlite IRC-50 (Na)

Mustafa

Shah

Akhtar

et al. 2008

Journal of Hazardous Materials

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“…(5). The spectrum exhibits a peak near 3500 cm -1 and a weaker peak near 1625 cm -1 , these correspond to the O-H stretching and H 3 O + bending vibration, respectively [3,37]. Presence of phenyl group intact with P atom is indicated by the aromatic C-H vibration at 3062 cm -1 and 2855 cm -1 along with a C-P vibration near 1150 cm -1 .…”

Section: Ft-ir and Uv-vis Spectroscopic Analysismentioning

confidence: 97%

“…Cr (III)-containing complexes and materials are used extensively in different oxidation reactions as catalyst to obtain value added organic fine chemicals [2]. Chromium phosphates synthesized previously, exhibit wide application in ion exchange [3], catalytic reactions including oxidative dehydrogenation [4], acid catalyzed reactions [5], etc. However, these phosphate-based catalysts have several drawbacks in large-scale industrial applications due to very low specific surface areas and as a consequence low turn over frequencies.…”

Section: Introductionmentioning

confidence: 99%

New Extra Large Pore Chromium Oxophenylphosphate: An Efficient Catalyst in Liquid Phase Partial Oxidation Reactions

Pal¹,

Paul²,

Bhaumik³

2009

TOCATJ

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Abstract:A new supermicroporous chromium oxophenylphosphate (CPP-1) has been synthesized using phenylphosphonic acid (PPA) as phosphorus source under hydrothermal condition at 443 K without using any structuredirecting agent (SDA). The material has been characterized by powder XRD, FE SEM-EDS, TEM, TG-DTA, N 2 sorption, XPS, FT IR, UV-Vis spectroscopic techniques and CHN chemical analysis. CPP-1 showed specific surface area of 313 m 2 g -1 with extra large supermicropores having dimension of ca. 1.4 nm. TEM result suggested lamellar type pore-wall structure for this material. It exhibited good catalytic property in partial oxidation of olefins in presence of tertbutylhydroperoxide (TBHP) as oxidant.

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Sorption of divalent metal ions on CrPO4

Cited by 27 publications

References 21 publications

Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism

Remediation of hexavalent chromium contamination in chromite ore processing residue by sodium dithionite and sodium phosphate addition and its mechanism

Chromium (III) removal by weak acid exchanger Amberlite IRC-50 (Na)

New Extra Large Pore Chromium Oxophenylphosphate: An Efficient Catalyst in Liquid Phase Partial Oxidation Reactions

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