Hexavalent chromium reduction by Providencia sp.

2006-6-1 · Microorganisms can play an important role in the detoxification and removal of hexavalent chromium from the polluted sites . It has been reported that hexavalent chromium …

How Do You Remediate Hexavalent Chromium …

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 …

Hexavalent Chromium (Cr VI) Bioreduction Potential of …

2022-10-15 · Effect of Process Conditions. A Bioreduction capacity of varying concentrations of ARE on hexavalent chromium is seen in Fig. 2.The Figure showed a smooth upward increase in Cr VI reduction with increasing ARE concentration from 0.01 to 0.1 mg/ml, which indicated an increment in Cr VI bioreduction from 65 to 96% in simulated chromium (VI) solution and …

Hexavalent Chromium Removal by Chemical …

2011-1-1 · 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 .

Hexavalent chromium reduction through redox electrolytic …

2019-2-15 · Hexavalent chromium reduction through redox electrolytic cell with urea and cow urine as anolyte J Environ Manage. 2019 Feb 15;232:554-563. doi: 10.1016/j.jenvman.2018.11.071. Epub 2018 Nov 30. Authors Saranya Sriram 1, Indumathi M Nambi 2, Raghuram Chetty 3 Affiliations 1 Department of ...

Hexavalent Chromium Reduction with Zero-Valent Iron …

2011-4-19 · Reduction of Cr(VI) carried out by Guha and Bhargava at different ZVI concentrations, for both high and low Cr(VI) concentrations, showed that the rate of Cr(VI) …

Hexavalent Chromium-Induced Alteration of Proteomic …

2013-7-5 · Hexavalent chromium [Cr(VI)] generated during industrial processes is carcinogenic. Although much is known about the deleterious effects caused by reactive oxygen species generated during the reduction of Cr(VI) after its absorption by biological systems, the precise mechanisms underlying Cr(VI) cytotoxicity remain poorly defined.

Hexavalent chromium risk reduction strategy

2005-10-1 · Details. Recommended strategy to reduce the environmental risks of using hexavalent chromium. Published 1 October 2005. Get emails about this page.

Reduction of hexavalent chromium with colloidal and

2013-3-27 · The PVP-Pd colloidal nanocatalysts were active on the complete reduction of Cr (VI) to Cr (III) with a rate of 22.2 mol Cr / (mol Pd min) or a turn-over frequency (TOF) of 1,329 h −1 at pH 4.0 and 45 °C. Magnetic Fe 3 O 4 support was used for recycling the palladium nanocatalysts.

Reduction mechanism of hexavalent chromium in aqueous …

2021-9-20 · The main form of chromium on the Cr-loaded FeS-GAC was Cr(III). Only 7% of Cr was hexavalent and formed inner-sphere complexation by iron(hydro)oxides. This indicates …

Bioreduction mechanisms of high-concentration …

The results showed that, when the concentration of metabisulfite was 2.0 g L-1, and the initial OD 600 was 0.33, the reduction rate of R. sphaeroides SC01 reached up to 91.3% for 500 mg L-1 Cr(VI) exposure at 96 h. Moreover, thiosulfate and sulfite also markedly increased the concentration of reduced Cr(VI) in R. sphaeroides SC01.

Highly efficient removal of hexavalent chromium in …

The removal of hexavalent chromium [Cr(VI)] from aqueous solutions using plate-like micro/nanostructured zero valent iron ... (VI) via reduction immobilization of chromium and has a Cr(VI) removal capacity of about 182 mg g −1 in electroplating wastewater with pH = 4.82. However, the ZVI nanoparticles easily aggregate; this leads to loss of ...

Photocatalytic reduction behavior of hexavalent chromium …

2017-6-5 · The Cr (VI) reduction efficiency decreased from 93% (MT-1.0 and MT-2.0) to 75% (MT) after 30 min of UV irradiation ( Fig. 8 a).The photocatalytic performance was in good …

Bioreduction of Hexavalent Chromium Using Microalgae

2018-11-4 · The trivalent chromium or Cr(III) and hexavalent chromium or Cr(VI) are the most stable chromium ions present in the environment [].Cr(VI) exists as Cr 2 O 7 2−, HCrO 4 −, H 2 CrO 4, and CrO 4 2−, and Cr(III) exists as Cr 3+, CrO +, Cr(OH) 2 +, HCrO 2, and CrO 2 − in the solution state [].Na 2 CrO 4 is a primary product of the lime treatment of minerals and further …

Hexavalent Chromium Reduction with Zero-Valent Iron …

2011-4-19 · 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 …

Hexavalent chromium reducing bacteria: …

2021-3-10 · Reduction of hexavalent chromium with bacteria Brief introduction of hexavalent chromium reducing bacteria The bioreduction of Cr (VI) is preferable to the detoxification of chromium because the Cr (III) is less toxic and …

Removal of hexavalent chromium from wastewater by …

2021-5-25 · 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 ).

Hexavalent Chromium Reduction under Fermentative …

2013-12-23 · Microbial reduction of toxic hexavalent chromium (Cr(VI)) in-situ is a plausible bioremediation strategy in electron-acceptor limited environments. However, higher [Cr(VI)] may impose stress on syntrophic communities and impact community structure and function. The study objectives were to understand the impacts of Cr(VI) concentrations on community structure …

Bioreduction mechanisms of high-concentration …

2022-10-13 · 1 troduction. The heavy metal (HM) hexavalent chromium [Cr(VI), as Cr 2 O 7 2− (dichromate) or CrO 4 − (chromate)] in solution is typically introduced into the environment from anthropogenic activities, such as chrome mining, smelting, and electroplating (Wang et al., 2017; Xia et al., 2020).Cr(VI) is known to be highly soluble and strongly oxidizing, which results in its …

Reduction of hexavalent chromium by cell-free extract of …

2005-9-15 · Cell-free extracts (CFEs) of chromium-resistant bacterium Bacillus sphaericus AND 303 isolated from serpentine soil of Andaman, India reduced Cr(VI) in in vitro condition, and the reductase activity was solely localized in the soluble cell-fractions (S12, S32, and S150). The enzyme was constitutive as the CFEs from cells grown in Cr(VI)-free and Cr(VI)-containing …

Bioreduction of hexavalent chromium by Pseudomonas …

2016-11-18 · Bioreduction of the very toxic hexavalent chromium ion [Cr(VI)] to the non-toxic trivalent chromium ion [Cr(III)] is a key remediation process in chromium-contaminated sites. In this study, we investigated the bioreduction of Cr(VI) by Pseudomonas stutzeri L1 and Acinetobacter baumannii L2. The optimum pH (5–10), temperature (27, 37 and 60 °C) and …

A study on the reduction of hexavalent chromium in …

Hexavalent chromium introduced to the water ecosystem is an important issue due to the toxic effect it poses. The first step of conventional treatment of wastewaters containing hexavalent …

Hexavalent chromium reduction by chromate-resistant …

2014-7-4 · Main effect analysis revealed that, five out of the nine variables (glucose, tryptone, KH 2 PO 4, (NH 4) 2 SO 4 and inoculum size) included in this study were found to have a positive …

Hexavalent Chromium Reduction and Precipitation by ...

2001-9-1 · Interactions of chromium with microorganisms and plants Carlos Cervantes, Jesús Campos-García, Silvia Devars, Félix Gutiérrez-Corona, Herminia Loza-Tavera Fems Microbiology Reviews 2001-05-01 25 (3): 335-347 :913

Removal of hexavalent chromium ions and mixture dyes …

2022-10-17 · Removal of hexavalent chromium ions and mixture dyes by electrospun PAN/graphene oxide nanofiber decorated with bimetallic nickel-iron LDH ... [email protected] nanochains with high saturation magnetization and abundant amino groups for hexavalent chromium adsorption and reduction. J. Hazard. Mater., 384 (2020), Article 121483, 10.1016/j ...

Hexavalent chromium reduction through redox electrolytic …

2019-2-15 · The Cr(VI) reduction efficiencies were 11.84 ± 0.27%, 10.55 ± 0.17%, 77.24 ± 0.38% at 24 h, 13.57 ± 0.25% at 72 h with glass frit, cation exchange membrane (CEM), sandwiched …

Mechanisms of hexavalent chromium resistance and …

Cr(VI) reduction by microorganisms may proceed on the cell surface, outside the cell, or intracellularly, either directly via chromate reductase enzymes, or indirectly via metabolite reduction of Cr(VI). The uptake of chromium ions is a biphasic process. The primary step is known as biosorption, a metabolic energyindependent process.

Determination of hexavalent chromium reduction using Cr …

2012-5-15 · Cr stable isotope measurements can provide improved estimates of the extent of Cr(VI) reduction to less toxic Cr(III). The relationship between observed (53)Cr/(52)Cr ratio shifts and the extent of reduction can be calibrated by determining the isotopic fractionation factor for relevant reactions. P …

Comparative evaluation of five plant extracts and juices for ...

2019-11-1 · The effectiveness of five plant extracts and juices, i.e. extracts of Camellia sinensis (green tea, GT), Syzygium aromaticum (clove, CL), Mentha spicata (spearmint, SM), Punica granatum juice (pomegranate, PG) and Red Wine (RW), for the production of nanoiron suspensions and their application for Cr (VI) reduction was investigated.

Hexavalent chromium removal from municipal wastewater …

2018-3-1 · Options that have been explored previously for removing aqueous chromium include: reduction via sulphur compounds and iron salts; electrocoagulation and electrodissolution using a variety of metallic or carbonic electrodes; photocatalytic reduction alongside organic matter or ferric iron and titanium dioxide; and biological reduction using bacteria and fungi (Barrera-Diaz …

Comparative evaluation of five plant extracts and juices for ...

2019-11-1 · Comparative evaluation of five plant extracts and juices for nanoiron synthesis and application for hexavalent chromium reduction. Science of the Total Environment ( IF 10.753 ) Pub Date : 2015-09-12, DOI: 10.1016/j.scitotenv.2015.08.091

Reduction of hexavalent chromium by cell-free extract of …

2005-9-15 · Abstract: Through the synergistic effect of reduction and mineralization by Bacillus strain T124, hexavalent chromium (Cr (VI)) is reduced to a state with lower toxicity, where stable mineralization occurs, and this results in the reduction of the migration and bioavailability of Cr (VI) in the environment.

Effects of citrate on hexavalent chromium reduction by …

2017-9-23 · @article{osti_1395357, title = {Effects of citrate on hexavalent chromium reduction by structural Fe(II) in nontronite}, author = {Liu, Xiaolei and Dong, Hailiang and Yang, Xuewei and Kovarik, Libor and Chen, Yu and Zeng, Qiang}, abstractNote = {Previous studies have shown that organic ligands could influence Cr(VI) reduction by aqueous Fe2+ and pyrite.