Calcium polysulfide treatment of Cr(VI)-contaminated soil

Chrysochoou, Maria; Ferreira, Daniel R.; Johnston, Chad P.

doi:10.1016/j.jhazmat.2010.03.052

Cited by 86 publications

(51 citation statements)

References 17 publications

(25 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Nearly 50% of Cr(VI) remained however after the reductive treatment. This is consistent with results found in previous studies (Chrysochoou et al, 2010;Wazne et al, 2007) on COPR, where the reduction rate of Cr(VI) was only 50 -60% using CaS5. Most of the remaining Cr(VI) in the Na2S2O4 (SD(12x))-treated sample is not leachable by the TCLP test, and is not readily exchangeable (based on sequential extraction data, above), presumably due to its presence inside larger COPR particles or agglomerates.…”

supporting

confidence: 93%

“…Due to the near-complete (> 99%) reduction of Cr(VI) by 12× Na2S2O4 in aqueous batch experiments both in the presence and absence of Fe(OH)3 (Fig. 2), the high TCLP Cr concentration most likely derives from the dissolution of Cr(III) during TCLP extraction (Chrysochoou et al, 2010;Dermatas et al, 2006). Further immobilization of Cr(III) was required to meet the EPA standard.…”

Section: Fig 2 Removal Efficiencies Of Cr(vi) In Aqueous Solution Umentioning

confidence: 99%

“…Of these, chemical reduction has proven the most popular. A variety of chemical reductants, including Fe(II) (Chrysochoou et al, 2010;Di Palma et al, 2015;Jagupilla et al, 2009), nZVI (Du et al, 2012;Wang et al, 2014a;Wang et al, 2014b), amorphous FeS2 (Li et al, 2016), calcium polysulfide (CaSx) (Chrysochoou and Johnston, 2015;Chrysochoou et al, 2012;Zhong et al, 2009;Dresel et al, 2008;Graham et al, 2006) , sodium thiosulfate (Na2S2O3) (Feng et al, 2015) and sodium dithionite (Na2S2O4) (Cheng et al, 2009;Fruchter et al, 2000;Istok et al, 1999;Khan and Puts, 2003;Su and Ludwig, 2005) have been utilized in laboratory and field studies to reduce Cr(VI) to Cr(III). The latter, sodium dithionite (Na2S2O4), is a widely used industrial chemical.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

View full text Add to dashboard Cite

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).

show abstract

supporting

confidence: 93%

Section: Fig 2 Removal Efficiencies Of Cr(vi) In Aqueous Solution Umentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

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

View full text Add to dashboard Cite

show abstract

“…3d), increasing release with pH up to a maximum attained at pH 10.8. Chrysochoou et al (2010) indicated that the presence of organic matter (as in forest soil) or sulfides (as in pyritic material) facilitates Cr(VI) reduction to Cr(III), which can precipitate at pH > 5. Avundainayagam et al (2001) found that Ca 2+ can favor Cr(VI) retention in calcareous soils, acting as a cationic bridge on negatively charged surfaces, or by means of CaCrO 4 formation (Perkins and Palmer, 2000).…”

Section: Sorptionmentioning

confidence: 99%

Cr(VI) sorption/desorption on untreated and mussel-shell-treated soil materials: fractionation and effects of pH and chromium concentration

et al. 2015

View full text Add to dashboard Cite

Abstract. We used batch-type experiments to study Cr(VI) sorption/desorption on granitic material, forest soil, pyritic material, mussel shell, and on forest soil and granitic material amended with 12 t ha −1 (1.2 kg m −2 ) shell, considering the effects of varying Cr(VI) concentration and pH. Sequential extractions were carried out to fractionate adsorbed Cr(VI) and to determine the stability of Cr(VI) retention. The pyritic material had the highest Cr(VI) retention capacity, whereas the granitic material showed the lowest retention potential. When high Cr concentrations were added, some saturation of the adsorbent surfaces became apparent, but Cr release remained low. The highest Cr retention was achieved at a very acid pH value, with release progressively increasing as a function of increasing pH. The amendment with 12 t ha −1 mussel shell did not cause marked changes in Cr(VI) retention. Sorption data were satisfactory adjusted to the Freundlich model. Regarding Cr(VI) fractionation, the soluble fraction (weakly bound) was dominant in mussel shell and in the unamended and amended granitic material, whereas more stable fractions dominated in the pyritic material (residual fraction) and in the forest soil (oxidizable fraction). In conclusion, the pyritic material presented the highest Cr(VI) retention capacity, while the retention was low and weak on the granitic material; mussel shell was not characterized by a marked Cr(VI) retention potential, and it did not cause remarkable increase in Cr(VI) retention when used to amend the granitic material or the forest soil.

show abstract

“…O polissulfeto de cálcio tem sido estudado e se mostrado um redutor promissor para redução de cromo hexavalente para cromo trivalente, com diversos estudos de campo documentados na literatura, tanto para solo, água subterrânea e Resíduos do Processamento de Minério de Cromita (COPR) (Storch, et al, 2002;Graham, et al, 2006;Charboneau, et al, 2006;Wazne, et al, 2007a;Wazne, et al, 2007b;Chrysochoou, et al, 2010;Chrysochoou & Ting, 2011;Pakzadeh & Batista, 2011;Chrysochoou, et al, 2012) (Storch, et al, 2002;Graham, et al, 2006;Charboneau, et al, 2006;Wazne, et al, 2007a;Wazne, et al, 2007b;Chrysochoou, et al, 2010;Chrysochoou & Ting, 2011;Pakzadeh & Batista, 2011;Chrysochoou, et al, 2012).…”

Section: Propriedades Químicas Do Polissulfeto De Cálciounclassified

Remediação De Cromo Hexavalente Utilizando Polissulfeto De Cálcio: Estudo De Caso: Rio De Janeiro

GODOY¹

View full text Add to dashboard Cite

Calcium polysulfide treatment of Cr(VI)-contaminated soil

Cited by 86 publications

References 17 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

Cr(VI) sorption/desorption on untreated and mussel-shell-treated soil materials: fractionation and effects of pH and chromium concentration

Remediação De Cromo Hexavalente Utilizando Polissulfeto De Cálcio: Estudo De Caso: Rio De Janeiro

Contact Info

Product

Resources

About