Laboratory batch experiments were conducted on heavily contaminated groundwater and chromium ore processing residue (COPR) samples to determine the rate and extent of hexavalent chromium [Cr(VI)] reduction and immobilization by nanoscale iron particles. Laboratory synthesized nanoscale iron particles (<100 nm, specific …
Cao and Zhang (2006) study the remediation of heavily contaminated groundwater and chromium ore processing residue (COPR) samples following the pathway of reduction and precipitation ...
As species we humans generate excessive amounts of waste and hence for sustainability we should explore innovative ways to recover them. The primary objective of this study is to demonstrate an efficient and optimum way to recover chromium and iron from chromite ore processing residues (COPR) for the production of chrome steel and …
Chromite ore processing residue (COPR) is a hazardous waste derived from the chromate extraction roasting process. Despite its (eco)toxicological potential, COPR has been dumped in uncontrolled surface landfills in several countries. The leaching of Cr(VI), resulting in the contamination of groundwater, is a key environmental risk arising from …
1. Introduction. In the industrial production of chromium and chromate, a large amount of Chromium Ore Processing Residue (COPR) is produced (Antony et al., 2013).COPR contains a lot of soluble hexavalent chromium Cr(VI) with high fluidity, high oxidation state, and high toxicity, which seriously threatens human life and health …
Chromium (Cr) contamination of natural resources from unregulated disposal of pretanning industrial waste, chromite ore processing residue (COPR), is a serious environmental concern, especially in developing countries. Although there have been studies on COPR characterization, the fate and transport of chromium emanating …
Chromite ore processing residue (COPR) is a major contaminant of Cr(VI)-contaminated soil. It is a by-product of chromium salt during the lime-based roasting process, which was estimated to be nearly 6 million tons in 2004 and has increased by 60,000 tons annually in China (Liu et al., 2020).
The reduction of chrome bearing ores in the production of industrial grade chromium compounds results in a waste rich in metals contamination. This byproduct is variously referred to as chromite ore processing residue, chrome ore processing residual or chrome tailings; for the purposes of MDE reports these variants are referenced as COPR.
1. Introduction. Chromite ore processing residues (COPR) are hazardous industrial wastes which have been disposed in surface soils at many commercial and industrial sites in the USA, UK, China, Japan, India and in many other countries (Dhal et al., 2013).One of the biggest threats of COPR to the environment is the release of …
DOI: 10.1016/j.jhazmat.2022.129754 Corpus ID: 251507844; Sufficient extraction of Cr from chromium ore processing residue (COPR) by selective Mg removal. @article{Zhang2022SufficientEO, title={Sufficient extraction of Cr from chromium ore processing residue (COPR) by selective Mg removal.}, author={Jing Zhang and Wenyu …
Chromite ore processing residue (COPR) is a waste byproduct of chromate production that contains high levels of hexavalent chromium (Cr(VI)). Although the high temperature chromite process was banned in several countries, its legacy still exists at numerous contaminated sites. For instance, New Jersey alone has over 2 million tons of …
Quantification of Mineralogical and Amorphous Species in Chromium Ore Processing Residue 133 wider GB layers. HB layers were in the vadose zone above or at the water table allowing for more regular
Experimental and modeling studies were conducted to delineate the reaction progress of chromite ore processing residue (COPR) upon hydration and the roles of brownmillerite and calcium aluminum chromium oxide hydrates (CAC) in the scavenging of hexavalent chromium. A kinetic study was conducted by preparing slurry samples with …
Chromite ore processing residue (COPR) is a byproduct produced in chromite processing at high temperature (1000–1200 °C). 2.5–3 tons of lime-based COPR were …
Consequently, chromium contaminant in groundwater, chromium ore processing residue (COPR), and sediment represents a significant environmental and public health concern [9]. The U.S. EPA maximum contaminant level (MCL) for total chromium in water is 0.1 mg/L [10].Chromium in natural waters exists primarily in +3 …
Caps were constructed on chromite ore processing residue (COPR) sites in the Kearny, New Jersey, area between 1989 and 1994 to prevent human exposure to hexavalent chromium (Cr(VI)). The caps comprise geotextile overlain by 100 mm of dense graded aggregate (DGA) and 100 mm of hot mix asphalt (HMA). Prior to constructing these …
Chromium (Cr) contamination of natural resources from unregulated disposal of pretanning industrial waste, chromite ore processing residue (COPR), is a …
For understanding both the environmental behavior and developing remediation treatments for chromium ore processing residue (COPR) it is important to identify all the potentially soluble sources of Cr(VI). Hydrogarnet has been identified as a major phase in COPR and it has been previously speculated that it has a capacity to …
This paper summarizes the characteristics of chromite ore processing residue (COPR) in terms of their chemical compositions, phases, and recycling potential of iron …
The present study evaluates the toxicity and bioavailability of Cr in sediments associated with chromite ore processing residue (COPR). Ten stations were sampled in the Hackensack River (NJ, USA) to represent a wide range of total Cr concentrations (199-3,970 mg/kg) with minimal interference from potentially toxic, co-occurring chemicals.
The slow release of Cr(VI) from chromium ore processing residue-contaminated soil (COPR-soil) poses a significant environmental risk. Here, vaterite embedded with Cr(VI) was identified as a Cr(VI) host-mineral in COPR-soil and accounted for the slow release of Cr(VI), which is difficult to treat. Almost all Cr(VI) (99.94%) in …
Chromium Ore Processing Residue (COPR) Site Initiative. Background and Site Location. The reduction of chrome bearing ores in the production of industrial grade chromium compounds results in a waste rich in metals contamination.
Much chromite ore processing residue (COPR), which is defined as hazardous solid waste due to virulent Cr (Ⅵ), is produced from chromium salt industry. …
Chromite ore processing residue (COPR) is a hazardous waste because of leachable chromium, especially Cr(vi). Therefore, ascorbic acid (AA) and blast furnace slag (BFS) have been used to detoxify and solidify COPR. On this basis, environmental stability experiments with high temperature and freeze–thaw cycles were
Hexavalent chromium contamination is a global environmental issue and usually reoccurs in alkaline reduced chromite ore processing residues (rCOPR). The oxidation of Cr(III) solids in rCOPR is one possible cause but as yet little studied. Herein, we investigated the oxidation of Cr(OH)3, a typical species of Cr(III) in rCOPR, at alkaline …
DOI: 10.1016/j.scitotenv.2018.12.042 Corpus ID: 58661567; Reduction and immobilization of hexavalent chromium in chromite ore processing residue using amorphous FeS2. @article{Li2019ReductionAI, title={Reduction and immobilization of hexavalent chromium in chromite ore processing residue using amorphous FeS2.}, author={Yunyi Li and …
Chromite ore processing residue (COPR) is a waste byproduct of chromate production that contains high levels of hexavalent chromium (Cr [VI]). Although the high …
Soda-based chromite ore processing residue (COPR) is a hazardous waste produced from chromium salt plants. In this study, detoxified water-washed chromite ore processing residue (DW-COPR) was investigated as a catalyst to activate peroxymonosulfate (PMS) to degrade tetracycline (TC) in the presence of visible light.
Hexavalent Chromium Solubility and Reduction in Alkaline Soils Enriched with Chromite Ore Processing Residue. Bruce R. James, Bruce R. James. ... (VI)] in alkaline soils enriched with chromite ore processing residue (COPR) should be based on oxidation-reduction and solubility interactions of Cr. A laboratory study characterized the …
Consequently, chromium contaminant in groundwater, chromium ore processing residue (COPR), and sediment represents a significant environmental and public health concern [9]. The U.S. EPA maximum contaminant level (MCL) for total chromium in water is 0.1 mg/L [10]. Chromium in natural waters exists primarily in +3 …
