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Hexavalent Chromium Wastewater Treatment - Industrial Wastes

Hexavalent chromium reduction is commonly accomplished using chemical reduction. Hexavalent chromium is reduced to trivalent chromium at acid pH using chemical reduction agents. Sodium bisulfide, sodium metabisulfide, and ferrous sulfate are among the common reduction agents used for small plants.

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Removal of hexavalent chromium from wastewater by Cu/Fe ...

As the pH decreases, the reduction of hexavalent chromium becomes easier 25,41,49. In addition, the equilibrium adsorption capacity Q e also decreased with increasing pH (Fig. S7, Table S2 ).

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Experimental modeling and optimization for the reduction ...

Zaib, Q., Park, H.S. & Kyung, D. Experimental modeling and optimization for the reduction of hexavalent chromium in aqueous solutions using ascorbic acid. Sci Rep 11, 13146 (2021). https://doi.org ...

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Full-scale Demonstration Testing of Hexavalent Chromium ...

Full-scale demonstration testing of hexavalent chromium reduction via stannous chloride application Tarrah Henrie1 | Sarah Plummer1 | John Orta2 | Steve Bigley3 | Craig Gorman4 | Chad Seidel4 | Kyle Shimabuku1 | Haizhou Liu2 1Corona Environmental Consulting, Fremont, California 2Department of Chemical and Environmental Engineering, University of

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Hexavalent chromium - Wikipedia

Reduction of toxicity of hexavalent chromium involves methods using chemicals, microbes and plants. Some removal technologies include transporting contaminated soil offsite to a landfill, using ion exchange resins to reduce chromium(VI) concentrations to less than detectable limit and granular activated carbon (GAC) filter.

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Evaluation of hexavalent chromium reduction by …

The reduction of Cr(VI) to less toxic Cr(III) is an important step in the remediation of Cr(VI)-contaminated environments. Microorganisms have shown to play a major role in the detoxification and removal of hexavalent chromium from the polluted sites .

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Determination of hexavalent chromium reduction using Cr ...

Determination of hexavalent chromium reduction using Cr stable isotopes: isotopic fractionation factors for permeable reactive barrier materials Abstract Cr stable isotope measurements can provide improved estimates of the extent of Cr (VI) reduction to less toxic Cr (III).

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How Do You Remediate Hexavalent Chromium Cr(VI)?

The chemical reaction between hexavalent chromium and ZVI reduces the concentration levels of hexavalent chromium and creates a less toxic daughter product, or transformed version of the contaminant, called trivalent chromium. Trivalent chromium further reacts with other minerals in the subsurface to create less water-soluble compounds.

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Reduction of hexavalent chromium by Ochrobactrum ...

Hexavalent chromium-resistant Ochrobactrum intermediumBCR400 was isolated from chromium contaminated soil collected from Vadodara, Gujarat. It reduced 100 mg Cr(VI)/L completely in 52 h with initial Cr(VI) reduction rate of 1.98 mg/L/h. The Cr(VI) reduction rate decreased with increase in Cr(VI) concentration from 100 to 500 mg/L.

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Reduction of hexavalent chromium by Ochrobactrum ...

Hexavalent chromium-resistant Ochrobactrum intermedium BCR400 was isolated from chromium contaminated soil collected from Vadodara, Gujarat. It reduced 100 mg Cr(VI)/L completely in 52 h with initial Cr(VI) reduction rate of 1.98 mg/L/h. The Cr(VI) reduction rate decreased with increase in Cr(VI) concentration from 100 to 500 mg/L.

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Bacterial Reduction of Hexavalent Chromium: Kinetic ...

Kinetic aspects of the bacterial reduction of hexavalent chromium (chromate: CrO 2-4) were investigated using Enterobacter cloacae strain HO1. E. cloacae strain HO1 could reduce hexavalent chromium to the trivalent form (Cr 3+) anaerobically.High concentrations of CrO 2-4 inhibited the reduction, and a substrate inhibition model gave a good fit to the …

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Department of Defense Cadmium and Hexavalent Chromium ...

Hexavalent chromium (Cr 6+) • Known carcinogen • Attacks the respiratory tract, liver, kidneys, skin, and eyes • Exposures occur during welding, coating processes, and surface finishing processes • Documented 75,219 pounds of Cr 6+ used in CY 2015 (5 depots); 67,173 pounds of Cr 6+ used in CY2017 (14 depots) Cadmium (Cd) • Known ...

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GROUNDWATER INFORMATION SHEET Hexavalent Chromium

chromium reduction is greater than the rate of transport of the aqueous hexavalent chromium off the impacted site, 4) the hexavalent chromium remains immobile, and 5) there is no net oxidation of Cr 3 to Cr 6 .

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Reduction of Hexavalent Chromium by Viable Cells of ...

Environmental contamination of hexavalent chromium [Cr(VI)] is of serious concern for its toxicity as well as mutagenic and carcinogenic effects. Bacterial chromate reduction is a cost-effective technology for detoxification as well as removal of Cr(VI) from polluted environment. Chromium resistant and reducing bacteria, belonging to …

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How Do You Remediate Hexavalent Chromium Cr(VI)?

A full implementation design plan was prepared for the reduction of hexavalent chromium and stabilization in both soil and groundwater. Case Study: Remediating Cr(VI) at a Former Wire Plating Site. At a wire manufacturing company, hexavalent chromium plating operations were performed from 1963 to 1981.

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0144tr.pdf - TOXICOLOGICAL REVIEW OF HEXAVALENT CHROMIUM ...

The authors demonstrated that hexavalent chromium is reduced to the trivalent form by incubation with gastric juices and concluded that reduction of hexavalent chromium to the trivalent form in the stomach significantly reduces absorption by the oral route of exposure.

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Change Hexavalent to trivalent chrome? Chrome Reduction

Hexavalent chromium reduction with SMBS is only the first step in the treatment. After that, the pH must be brought back up and the green trivalent chrome precipitated out. Regards, Ted Mooney, P.E. Striving to live Aloha finishing.com - Pine Beach, New Jersey ^

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(PDF) Temperature Impact on Reverse Osmosis Permeate Flux ...

The present era is seeking our attention on the dilemma caused by the contamination of the aquatic system with chromium (Cr) and nickel (Ni). Amid Ni and Cr oxidation states, hexavalent Cr (Cr(VI ...

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Factors affecting the reduction and absorption of ...

Factors affecting the reduction and absorption of hexavalent chromium in the gastrointestinal (GI) tract: Potential impact on evaluating the carcinogenic ity of ingested hexavalent chromium. Hexavalent chromium is a known human carcinogen …

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Hexavalent chromium reducing bacteria: mechanism of ...

Ranieri E, Gikas P (2014) Effects of plants for reduction and removal of hexavalent chromium from a contaminated soil. Water Air Soil Pollut:225. Sagar S, Dwivedi A, Yadav S, Tripathi M, Kaistha SD (2012) Hexavalent chromium reduction and plant growth promotion by Staphylococcus arlettae Strain Cr11. Chemosphere 86:847–852

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Reduction/Coagulation/Filtration for Hexavalent …

Hexavalent Chromium Removal from Drinking Water Nicole Blute, PhD, PE Ying Wu, DEnv, PE Ramon Abueg, PE. Agenda •Introduction ... Cr 6 Reduction by Ferrous Iron at Various Reduction Times with Chlorination (Bench-Scale Testing Results) Cr(VI) in Reduced Water Cr(VI) in Chlorinated Water

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Hexavalent Chromium Removal | AdEdge Water Technologies

Hexavalent Chromium Reduction and Treatment Chromium exists naturally and commonly in two forms: trivalent chromium [Cr (III)] and hexavalent chromium [Cr (VI)]. While Cr (III) is used as a nutrition supplement since it is necessary to the human diet, Cr (VI) has been a cause of concern because of its level of toxicity.

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Reduction of hexavalent chromium by a moderately ...

The isolates were also screened for hexavalent chromium reduction during growth in Cr(VI) supplemented MH medium under continuous shaking (120 rpm) at 32 °C. Since all the isolates showed MIC values > 2 mM Cr(VI), reduction studies were carried out uniformly at a sub-lethal concentration of 2 mM Cr(VI) in the medium.

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Hexavalent chromium reduction by an actinomycete ...

Environmental contamination by hexavalent chromium, Cr(VI), presents a serious public health problem. This study assessed the reduction of Cr(VI) by intact cells and a cell-free extract (CFE) of an actinomycete, Arthrobacter crystallopoietes (strain ES 32), isolated from soil contaminated with dichromate.

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CLU-IN | Contaminants > Chromium VI > Treatment Technologies

This article discusses the potential use of Brucella sp to reduce hexavalent chromium to trivalent. Results indicate 100 percent reduction at 50 mg/L and approximately 42 percent at 300 mg/L. Stimulation of in situ bioprecipitation for the removal of hexavalent chromium from contaminated groundwater

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Hexavalent chromium reduction kinetics in rodent stomach ...

1. Introduction. Extracellular reduction of hexavalent (Cr(VI)) to trivalent chromium (Cr(III)) in gastric fluid is a well-recognized detoxification process (De Flora and Boido, 1980, De Flora, 2000) thought to protect against systemic toxicity of ingested Cr(VI) at doses that do not overwhelm reductive capacity.Recently, chronic exposure to Cr(VI), in the form of …

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US20090014094A1 - Methods for Reducing Hexavalent Chromium ...

The present invention is directed to trivalent chromate conversion coatings for plated metals, and more particularly, to methods for reducing hexavalent chromium in trivalent chromate conversion coatings. In one embodiment, such method includes placing a metal article having a trivalent chromate conversion coating in a reducing solution.

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The reduction of hexavalent chromium by sulphite in …

The reduction of hexavalent chromium, Cr(VI), in unbuffered aqueous solution by sulphite was investigated as a function of pH, possible dosage and contact time required to reach equilibrium. Dissolved Na 2 Cr 2 O 7.2H 2 O served as the aqueous source of Cr(VI).

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EPA Ground Water Issue

Reduction of Hexavalent Chromium Cr(Vl) is a strong oxidant and is reduced in the presence of electron donors. Electron donors commonly found in soils include aqueous Fe(l I), ferrous iron minerals, reduced sulfur, and soil organic matter. The …

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(PDF) The reduction of hexavalent chromium by sulphite in ...

The reduction of hexavalent chromium, Cr(VI), in unbuffered aqueous solution by sulphite was investigated as a function of pH, possible dosage and contact time required to reach equilibrium.

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Hexavalent chromium reduction by zero-valent magnesium ...

The discharge of hexavalent chromium in aquatic environments represents an issue of great concern. The chemical reduction of Cr 6+ to Cr 3+, which is less mobile and harmful, is a suitable approach for chromium removal.In this regard, in comparison to other reactive metals, the use of zero-valent magnesium (ZVM) has several advantages.

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(PDF) Hexavalent Chromium Removal by Chemical ...

reduction rate of hexavalent chromium. The pH value of 2 and contact time of 5 Mins with the dosage of sodium metabisulphite as 80 mg/l were found to be optimum

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Chromium adsorption and Cr(VI) reduction to trivalent ...

Hexavalent chromium can be reduced to the trivalent state using various reductive agents or it can be removed from solution by surface-active adsorbents. In this study, both of these methods were evaluated using soya cake. A high efficiency for reduction of Cr(VI) to trivalent chromium was observed at pH < 1.

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