In Situ Chemical Reduction of Cr(VI) in Groundwater Using a Combination of Ferrous Sulfate and Sodium Dithionite: A Field Investigation

Ludwig, Ralph D.; Su, Chunming; Lee, Tony R.; Wilkin, Richard T.; Acree, Steven D.; Ross, Randall R.; Keeley, Ann

doi:10.1021/es8016914

Cited by 24 publications

(24 citation statements)

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“…ZVI produced by the BRM, usually in micro (μZVI) or nano size (nZVI), has surface areas in the Clifford et al (1986); Erdem and Tumen (2004); Ludwig et al (2007); Seaman et al (1999); Su and Ludwig (2005) Alowitz and Scherer (2002) range of 20-40 m 2 /g, which can yield 10-1,000 times greater reactivity compared with granular ZVI (Karn et al 2009). Although nZVI particles made by BRM are highly reactive, this process is not easy to implement because of the large volumes of hydrogen gas generated in the reaction and because borohydride salts are expensive reagents (Hoch et al 2008).…”

Section: Laboratory-synthesized Zvi or Zvi-based Materialsmentioning

confidence: 99%

Hexavalent Chromium Reduction with Zero-Valent Iron (ZVI) in Aquatic Systems

Gheju

2011

Water Air Soil Pollut

330

186

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Hexavalent chromium is a heavy metal used in a variety of industrial applications which is highly toxic to humans, animals, plants and microorganisms. Moreover, it is a well-established human carcinogen by the inhalation route of exposure and a possible human carcinogen by the oral route of exposure. Therefore, it should be removed from contaminated waters. Its reduction to trivalent chromium can be beneficial because a more mobile and more toxic chromium species is converted to a less mobile and less toxic form. During the last two decades, there has been important interest in using zero-valent iron (ZVI) as a Cr(VI)-reducing agent. A considerable volume of research has been carried out in order to investigate the mechanism and kinetics of Cr(VI) reduction with ZVI, as well as the influence of various parameters controlling the reduction efficiency. Therefore, the purpose of this review was to provide updated information regarding the developments and innovative approaches in the use of ZVI for the treatment of Cr(VI)-polluted waters.

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Section: Laboratory-synthesized Zvi or Zvi-based Materialsmentioning

confidence: 99%

Hexavalent Chromium Reduction with Zero-Valent Iron (ZVI) in Aquatic Systems

Gheju

2011

Water Air Soil Pollut

330

186

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“…) and microbial carbon sources (molasses, emulsified oil, etc.) have been studied for in situ remediation, and many sites contaminated with Cr(VI) have been remediated successfully (Cantrell et al 1995;Khan and Puls 2003;Ludwig et al 2007;Turan and Altundoğan 2014;Höhener and Ponsin 2014;Wilkin et al 2014).…”

Section: Introductionmentioning

confidence: 99%

Mechanism and Kinetics of Hexavalent Chromium Chemical Reduction with Sugarcane Molasses

Chen

Zhao

Zhang

et al. 2015

Water Air Soil Pollut

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Sugarcane molasses, which is a kind of microbial carbon source, is a viscous by-product of the refining of sugarcane into sugar. However, experiments were designed to ascertain the mechanism and kinetics of Cr(VI) reduction with sugarcane molasses without adding microbes in aqueous solution. Results indicated that sugarcane molasses can reduce Cr(VI) to Cr(III) at pH values that range from 2.0 to 6.1 when no bioreduction occurs in the reaction. Furthermore, the reaction mechanism was proven to be that Cr(VI) acts as an electrophile that readily accepts electrons from the phenolic hydroxyl group of plant polyphenol, and it is then reduced to Cr(III) and in the process oxidizes the phenolic hydroxyl group to a quinone. Meanwhile, the reaction could be described by the pseudo-first-order kinetic model with respect to Cr(VI) concentration. The reaction rate constants were 324.2, 65.9, 21.9, and 14.4 h −1 when pH values were 2.0, 3.5, 5.0, and 6.1, respectively, at 20°C. The k obs increased 3.36, 7.02, and 13.48 times with the temperature adjusted from 5 to 10, 20, and 30°C.

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“…It is a common method to pretreat Cr(VI)-bearing wastes to reduce Cr(VI)-Cr(III) (Rodríguez-Piñero et al, 1998). The most commonly used reducing agents are reduced iron and reduced sulfur compounds (Li, 2003;Erdema and Tumen, 2004;Graham et al, 2006;Ludwig et al, 2007;Wazne et al, 2007;Cheng et al, 2009). In recent years, there has been growing concern with the use of ZVI for the stabilization of Cr(VI) in water and soil (Cissoko et al, 2009;Mitra et al, 2011;Singh et al, 2012).…”

Section: Introductionmentioning

confidence: 99%