Reduction of Hexavalent Chromium in Soil and Ground Water Using Zero-Valent Iron Under Batch and Semi-Batch Conditions

• Published in: Water, air, and soil pollution Vol. 197; no. 1-4; pp. 49 - 60
• Main Authors: Franco, Débora V., Da Silva, Leonardo M., Jardim, Wilson F.
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-02-2009; Springer; Springer Nature B.V
• Subjects: Analytical chemistry; Applied sciences; Atmospheric Protection/Air Quality Control/Air Pollution; Carboxymethylcellulose; Cellulose; Chemical analysis; Chemical reduction; Chromium; Climate Change/Climate Change Impacts; Comparative studies; Contamination; Decontamination. Miscellaneous; Drinking water; Earth and Environmental Science; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Environment; Environmental monitoring; Environmental protection; Exact sciences and technology; Groundwater; Groundwaters; Hydrogeology; Iron; Nanoparticles; Natural water pollution; Oxidation; Pollution; Pollution, environment geology; Sandy soils; Slurry reactors; Soil and sediments pollution; Soil contaminants; Soil contamination; Soil pollution; Soil remediation; Soil Science & Conservation; Studies; Water Quality/Water Pollution; Water treatment and pollution; Hexavalent chromium; Carboxymethyl cellulose; Colloidal zerovalent iron; Contaminated soil; Chromium immobilization; Contaminated soil . Hexavalent chromium . Carboxymethyl cellulose; Iron II Sulfates; In situ; Zerovalent metal; Iron; Soil pollution; Reducing agent; Heavy metal; Chemical reduction; Trace element; Decontamination; Batchwise; Granular material; Chemical treatment; Colloidal zerovalent iron . Chromium immobilization; Water pollution; Performance; Chromium VI; Semicontinuous; Comparative study; Colloid particle; Ground water
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-008-9790-0

Chemical remediation of soil and groundwater containing hexavalent chromium (Cr(VI)) was carried out under batch and semi-batch conditions using different iron species: (Fe(II) (sulphate solution); Fe
0
G
(granulated elemental iron); ZVIne (non-stabilized zerovalent iron) and ZVIcol (colloidal zerovalent iron). ZVIcol was synthesized using different experimental conditions with carboxymethyl cellulose (CMC) and ultra-sound. Chemical analysis revealed that the contaminated soil (frank clay sandy texture) presented an average Cr(VI) concentration of 456 ± 35 mg kg
−1
. Remediation studies carried out under batch conditions indicated that 1.00 g of ZVIcol leads to a chemical reduction of ∼280 mg of Cr(VI). Considering the fractions of Cr(VI) present in soil (labile, exchangeable and insoluble), it was noted that after treatment with ZVIcol (semi-batch conditions and pH 5) only 2.5% of these species were not reduced. A comparative study using iron species was carried out in order to evaluate the reduction potentialities exhibited by ZVIcol. Results obtained under batch and semi-batch conditions indicate that application of ZVIcol for the “in situ” remediation of soil and groundwater containing Cr(VI) constitutes a promising technology.