نتایج جستجو برای: cr vi

تعداد نتایج: 85905  

2012
Siew-Leng Loo

The objectives of this study are to evaluate the efficiency of removal of hexavalent chromium (Cr(VI)) in a sequencing batch reactor (SBR) and to ascertain the fate of Cr(VI) in the treatment process. An SBR was operated with the FILL, REACT, SETTLE, DRAW and IDLE periods in the time ratio of 2:12:2:1.5:6.5 for a cycle time of 24 h. The study was divided into 5 phases with the addition of 0.5, ...

Journal: :Environmental Health Perspectives 2002
Susan K Vilcheck Travis J O'Brien Daryl E Pritchard Linan Ha Susan Ceryak Jamie L Fornsaglio Steven R Patierno

Fanconi anemia (FA) is an autosomal recessive disorder characterized by diverse developmental abnormalities, progressive bone marrow failure, and a markedly increased incidence of malignancy. FA cells are hypersensitive to DNA cross-linking agents, suggesting a general defect in the repair of DNA cross-links. Some forms of hexavalent chromium [Cr(VI)] are implicated as respiratory carcinogens a...

Journal: :Journal of inorganic biochemistry 2004
Viviana Roldán Mabel Santoro Juan C González Juan Manuel Salas-Peregrin Sandra Signorella Luis F Sala

The oxidation of D-lactobionic acid by Cr(VI) yields the 2-ketoaldobionic acid and Cr(3+) as final products when a 20-times or higher excess of the aldobionic acid over Cr(VI) is used. The redox reaction takes place through a complex multistep mechanism, which involves the formation of intermediate Cr(IV) and Cr(V) species. Cr(IV) reacts with lactobionic acid much faster than Cr(V) and Cr(VI) d...

This work describes the synthesis of a novel magnetic graphene oxide composite for removal of Cr(VI) ions. The synthesized nanosorbent were characterized with various techniques such as FT-IR, X-ray diffraction (XRD), scanning electron microscopy (SEM), elemental analysis and vibrating sample magnetometry (VSM). This material is illustrated to represent a viable sorbent for the removal of Cr(VI...

ژورنال: :دانش آب و خاک 2013
سیدرسول حسینی شاهین اوستان ناصر علی اصغرزاد نصرت‎اله نجفی

اکسایش cr(iii) به cr(vi) در خاک سبب افزایش تحرک کروم و خطرات زیست محیطی ناشی از آن می­شود. لذا، بررسی عوامل مؤثر بر این واکنش حائز اهمیت است. در این تحقیق اثر ph، غلظت کروم و ماهیت محلول زمینه بر اکسایش کروم در تعدادی از خاک­های شمال و شمال غرب کشور مورد مطالعه قرار گرفت. نتایج نشان داد که اکسایش cr(iii) به cr(vi) در محیط نیتراتی با افزایش ph از 3 به 5 افزایش یافت ولی در محیط کلرایدی بیشترین اک...

Journal: :Environmental science & technology 2003
Jeanine S Geelhoed Johannes C L Meeussen Martin J Roe Stephen Hillier Rhodri P Thomas John G Farmer Edward Paterson

Chromite ore processing residue (COPR), derived from the so-called high lime processing of chromite ore, contains high levels of Cr(III) and Cr(VI) and has a pH between 11 and 12. Ferrous sulfate, which is used for remediation of Cr(VI) contamination in wastewater and soils via reduction to Cr(III) and subsequent precipitation of iron(III)/chromium(III) hydroxide, has also been proposed for rem...

2006
R. Michalski

Chromium exists usually in the (III) or (VI) oxidation states. In contrast to Cr(III), which is essential to mammalian systems, Cr(VI) is dangerous for humans due to its toxicity and carcinogenic properties. Cr(VI) compounds are highly soluble, mobile and bioavailable compared to Cr(III) species. Chromium is usually analyzed using instrumental methods such as AAS or ICP, which are accurate and ...

Journal: :Journal of hazardous materials 2008
Mohamed Hasnain Isa Naimah Ibrahim Hamidi Abdul Aziz Mohd Nordin Adlan Nor Habsah Md Sabiani Ali Akbar Lorestani Zinatizadeh Shamsul Rahman Mohamed Kutty

This study proposed an oil palm by-product as a low-cost adsorbent for the removal of hexavalent chromium [Cr (VI)] from aqueous solution. Adsorption of Cr (VI) by sulphuric acid and heat-treated oil palm fibre was conducted using batch tests. The influence of pH, contact time, initial chromium concentration and adsorbent dosage on the removal of Cr (VI) from the solutions was investigated. The...

2016
Guey-Horng Wang Chiu-Yu Cheng Man-Hai Liu Tzu-Yu Chen Min-Chi Hsieh Ying-Chien Chung

Fast hexavalent chromium (Cr(VI)) determination is important for environmental risk and health-related considerations. We used a microbial fuel cell-based biosensor inoculated with a facultatively anaerobic, Cr(VI)-reducing, and exoelectrogenic Ochrobactrum anthropi YC152 to determine the Cr(VI) concentration in water. The results indicated that O. anthropi YC152 exhibited high adaptability to ...

Journal: :Toxicological sciences : an official journal of the Society of Toxicology 2015
Julieta Martino Amie L Holmes Hong Xie Sandra S Wise John Pierce Wise

Particulate hexavalent chromium (Cr(VI)) is a well-established human lung carcinogen. Lung tumors are characterized by structural and numerical chromosome instability. Centrosome amplification is a phenotype commonly found in solid tumors, including lung tumors, which strongly correlates with chromosome instability. Human lung cells exposed to Cr(VI) exhibit centrosome amplification but the und...

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