Solidification/stabilization of Cr(VI) with cement

Wang, S.; Vipulanandan, C.

doi:10.1016/s0008-8846(99)00265-3

Cited by 130 publications

(68 citation statements)

References 8 publications

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“…compounds are slightly more soluble, and those containing Cr 6? show the highest solubility compared to those containing Cr 3? [13,28]. Therefore, Cr 6?…”

Section: Stabilization Of Chromiummentioning

confidence: 97%

Stabilization of Cr(III) wastes by C3S and C3S hydrated matrix: comparison of two incorporation methods

Schutter

et al. 2015

Mater Struct

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In the present study, the influence of Cr(III) on the properties of C 3 S and its stabilization in C 3 S hydrates was investigated by either direct incorporation as Cr 2 O 3 during C 3 S preparation or introduced as nitrate salt during hydration. Levels of Cr used were from 0.1 to 3.0 wt% of C 3 S. The effect of Cr on the polymorph and hydration of C 3 S and its immobilization in the hydrates was detected by means of DTA/TG, XRD, isothermal calorimeter and ICP-AES, etc. When doped during sintering process, Cr caused a C 3 S polymorph transformation from T1 to T2 and led a decomposition of C 3 S into C 2 S and CaO resulting in high f-CaO content. Cr doping showed an obvious promotion effect on the hydration properties. The promotion effect decreased when the Cr addition increased to 3.0 wt%. When Cr was added as nitrate salt, Cr showed a retardation effect on the hydration of C 3 S due to the formation of Ca 2 Cr(OH) 7 Á3H 2 O, which resulted in a high degree of Cr stabilization.

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“…compounds are slightly more soluble, and those containing Cr 6? show the highest solubility compared to those containing Cr 3? [13,28]. Therefore, Cr 6?…”

Section: Stabilization Of Chromiummentioning

confidence: 97%

Stabilization of Cr(III) wastes by C3S and C3S hydrated matrix: comparison of two incorporation methods

Schutter

et al. 2015

Mater Struct

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“…The immobilization of Cr(VI) by OPC was achieved due to the formation of the low solubility complex compounds, such as CaCrO4 [53,54] and CrO4-ettringite. CaCrO4 was formed by the reaction between Cr and Ca 2+ at a high pH value.…”

Section: Suppression Of Cr Elutionmentioning

confidence: 99%

A Suppression Method for Elution of F−, [B(OH)4]−, AsO43−, and CrO42− from Industrial Wastes Using Some Inhibitors and Crushed Stone Powder

et al. 2018

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Abstract:The disposal and the reuse of industrial wastes have become increasingly difficult due to the elution of hazardous anions, such as F − , [B(OH) 4 ] − , AsO 4 3− , and CrO 4 2− . Effective methods for removing hazardous ions and reusing solid wastes are urgently required. In this study, Ca(OH) 2 , MgCl 2 , and BaCl 2 were added to reduce the elution concentrations of F, B, As, and Cr by coprecipitating insoluble inorganic salts. After this, ordinary Portland cement (OPC) was added to the ion exchange and solidified with these hazardous ion-containing substances. The addition of crushed stone powder (CSP), which was a by-product of the process of crushing aggregates or sawing stone, inhibited the elution of hazardous ions and improved the inhibition effect of OPC. The elution concentrations of F, B, As, and Cr were successfully reduced from their maximum elution concentration of 10 mg/L to below the environmental standards values of Japan. A simultaneous inhibition method for the elution of F, B, As, and Cr from industrial wastes has been developed successfully and would be able to promote the reuse and recycling of CSP and other industrial wastes.

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“…To greater amount of Cr (VI) added, the material strength is lower 6 . But the Palomo 7 study shows that the mechanical strength increases with increasing addition of Cr (VI), forming CaCrO 4 .…”

Section: Compressive Strengthmentioning

confidence: 99%

Effect of Chemically Treated Leather Shaving Addition on characteristics and microstructure of OPC mortars

2012

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The growing concern with environmental issues in tanneries and the search for a technological solution to their wastes are evaluated in this study. The leather shaving was chemically treated aiming the immobilization of the chromium ion on ordinary Portland cement (OPC) matrix. Cementitious mortars were obtained by adding different proportions of waste treated solutions (5 and 10% compared to the cement mass) and after 28 days, the samples were evaluated in relation to their physical properties, axial compressive strength and, for the most promising compositions, microstructural characterization analyses tests were realized. Results showed that the alternatives used for the pretreatment were effective for the leather shaving dissolution; but the results analysis describes little change in pH values when the treated waste is added in three different media. The best axial compressive strength after 28 days age were obtained by addition of diluted phosphoric acid solution at low concentration, although this addition minimize the Portlandite formation and favor the calcium phosphate formation.

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Solidification/stabilization of Cr(VI) with cement

Cited by 130 publications

References 8 publications

Stabilization of Cr(III) wastes by C3S and C3S hydrated matrix: comparison of two incorporation methods

Stabilization of Cr(III) wastes by C3S and C3S hydrated matrix: comparison of two incorporation methods

A Suppression Method for Elution of F−, [B(OH)4]−, AsO43−, and CrO42− from Industrial Wastes Using Some Inhibitors and Crushed Stone Powder

Effect of Chemically Treated Leather Shaving Addition on characteristics and microstructure of OPC mortars

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