Fixed-bed flow experiments with supported green nZVI for the remediation of contaminated waters: Effect of pH and background solution composition.

Aim of this study is to evaluate the performance of a nanocomposite material (R-nFe), consisting of nano zero valent iron (nZVI) and a cation exchange resin, for Cr(VI) reduction and heavy metals removal from contaminated water streams. The effect of pH and the background solution composition was investigated by conducting three columns tests. In Column I, the experiments were carried out using NaCl as background electrolyte while in Column II and III the background solution consisted of 50% tertiary effluents of a waste water treatment plant and 50% deionized water.

Hexavalent chromium reduction by gallic acid.

Cr(VI) is widely used in industry and often large quantities have been accidently or due to lack of precautions released at the environment. The presence of high concentrations of Cr(VI) in waste streams causes concern due to its toxicity and solubility. However the Cr(III) is a useful micronutrient in human diet.

Chromium Removal Using Soil Loaded with Green Iron Nanoparticles.

Chromate is considered as a serious environmental problem due its toxicity. Iron nanoparticles produced by green tea polyphenols (GT-nZVI) is a powerful reductant, which can effectively reduce Cr(VI) to Cr(III). Nano ZVI suspension was initially conceived ideal for direct injection in the contaminated aquifers.

Evaluation of Calcium Polysulfide as a Reducing Agent for the Restoration of a Cr(VI)-Contaminated Aquifer.

This study aims at investigating the efficiency of calcium polysulfide (CPS) as a reducing agent for decontamination of a heavily Cr(VI)-contaminated aquifer. Batch experiments were carried out in order to evaluate the effect of time, CPS concentration and the presence of soil on the reductive behavior of CPS. CPS was used at several stoichiometric excesses with respect to Cr(VI) concentration detected in the contaminated groundwater.

Continuous Flow Process for Cr(VI) Removal from Aqueous Solutions Using Resin Supported Zero-Valent Iron.

The objective of the present study was to evaluate the performance of a nanocomposite material consisting of nano zero valent iron and a cation exchange resin, for the reduction of chromate, by conducting column tests. A cationic resin, Amberlyst 15, was selected as porous host material. The synthesis of the nanocomposite material (R-nFe) was carried out using Green Tea extract to obtain the reduction of adsorbed Fe(III) to the elemental state Fe(0).