Support Tool for Identifying In Situ Remediation Technology for Sites Contaminated by Hexavalent Chromium

Abstract

Sites contaminated by hexavalent chromium raise concerns relating to the toxicity of the pollutant, as well as for the increased solubility of its compounds, which helps it to seep into aquifers. Chemical and biological in situ treatment technologies, with good potential in terms of environmental sustainability, have recently been designed and implemented on a wide scale. A useful support tool is shown in the manuscript in the preliminary phase of assessing possible technologies applicable according to the site-specific characteristics of sites. The actual efficacy of the technologies identified should nevertheless be verified in laboratory trials and pilot tests.

Metagenomic Analysis Reveals Microbial Interactions at the Biocathode of a Bioelectrochemical System Capable of Simultaneous Trichloroethylene and Cr(VI) Reduction

“…In respect of Cr(VI) remediation, anaerobic microorganisms capable of Cr(VI) to Cr(III) reduction (i.e., Pseudomonas dechloromaticans , Enterobacter cloacae , Shewanella oneidensis , and Clostridium chromiireducens ) and with Cr(VI) tolerance (i.e., Bacillus sp., Leucobacter sp., Exiguobacterium sp., Microcococcus sp., Rhodococcus sp., Arthrobacter sp., Achromobacter sp., and Ochrobactrum sp.) have been reported ( Horitsu et al, 1987 ; Turick and Apel, 1997 ; Desai et al, 2008 ; Sarangi and Krishnan, 2008 ; Elangovan et al, 2010 ; Beretta et al, 2018 ; Kabir et al, 2018 ). Several studies also demonstrated that indirect Cr(VI) bioreduction is achievable through injections of biodegradable organic substrates that prompt anaerobic conditions and reductant production such as iron and sulfur species capable of mediating Cr(VI) reduction to Cr(III) ( Kim et al, 2001 ; Somenahally et al, 2013 ; Beretta et al, 2018 , 2019 ).…”

“…have been reported ( Horitsu et al, 1987 ; Turick and Apel, 1997 ; Desai et al, 2008 ; Sarangi and Krishnan, 2008 ; Elangovan et al, 2010 ; Beretta et al, 2018 ; Kabir et al, 2018 ). Several studies also demonstrated that indirect Cr(VI) bioreduction is achievable through injections of biodegradable organic substrates that prompt anaerobic conditions and reductant production such as iron and sulfur species capable of mediating Cr(VI) reduction to Cr(III) ( Kim et al, 2001 ; Somenahally et al, 2013 ; Beretta et al, 2018 , 2019 ). Further, under anaerobic conditions, direct Cr(VI) reduction can be mediated by membrane-bound reductases encoded by mtrA , mtrB , mtrC genes, and soluble enzymes (e.g., soluble cytochrome c3; Belchik et al, 2011 ; Thatoi et al, 2014 ).…”

Groundwater Contamination, Subsurface Processes, and Remediation Methods: Overview of the Special Issue of Water on Groundwater Contamination and Remediation

“…The call for papers for this special issue invited papers addressing passive methods, such as monitored natural attenuation, and ex-situ methods, such as pump-and-treat, but the response focused entirely on in-situ methods, such as bioremediation or chemical oxidation. In particular, two studies present novel approaches to predict and enhance the performance of remediation techniques: Beretta et al [7] present a support tool for identifying remediation options for hexavalent chromium, while Moradi et al [14] offer an original cross-pollination between bioremediation and energy storage, both of which depend on subsurface temperature. These papers show, once again, the value of creativity in science.…”

“…Under the heading of natural sources, Vera et al [5] focus on arsenate, and Haluska et al [6] address sulfate-whose source can be natural or anthropogenic. Most of the studies considered anthropogenic sources, with Beretta et al [7] and Haluska et al [6] addressing the industrial additive and known carcinogen hexavalent chromium, Plymale et al [8] focusing on the toxic salt ferrocyanide, Haluska et al [6] measuring the organic contaminants 1,4-dioxane and hexahydro-1,3,5-trinitro-s-triazine (RDX), Prieto-Amparán et al [9] studying sewage effluent, and Wells et al [10] tracking the fertilizer-derived anion nitrate. As a particular subset of anthropogenic contaminants, two studies discuss emerging contaminants, particularly related to hydrocarbon resources, as Hu et al [11] study oil shale development, while Ning et al [12] focus on petroleum contamination.…”

Application of nanoscale zero-valent iron in hexavalent chromium-contaminated soil: A review

“…Besides, Cr(VI) is also known as a strong oxidant and has a 400-fold higher toxicity than Cr(III) [7]. It is one of the 17 most dangerous toxic substances and a Class A carcinogen [8]. In addition, according to a document released by the United States Environmental Protection Agency [9], Cr(VI) is identified as the most important hazardous pollutant [10].…”