نتایج جستجو برای: chromium vi

تعداد نتایج: 64211  

2016
Krystyna PYRZYNSKA

Chromium is an element with important biological characteristics, depending on its different species. Cr(III) is considered as essential; however, the Cr(VI) form is classified as carcinogenic. For this reason, speciation analysis in food samples is a very important question. The proposed data procedures for chromium redox speciation in the literature can be divided into those with the use of o...

ارغوان, فاطمه السادات, اسلامی, هادی, انتظاری, اطهر, تقی زاده, علی اکبر, خدادادی, مریم, خسروی, رسول,

Background and Objectives: Because of toxical and hazardous properties of hexavalent chromium (Cr(VI)), its removal by an economical and efficient method is necessary. The use of activated carbon, as an adsorbent, is a common and effective method for hexavalent chromium removal. Thus the aim of this study was to produce granular and powdered activated carbon form Peganum Harmala and compare the...

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...

Journal: :international archives of health sciences 0
mostafaii gh.r. sayyaf h. environmental health engineering department, health faculty, kashan university of medical sciences, kashan, iran iranshahi l. mosavi gh.a. aseman e.

aims: heavy metals are the main pollutants in nature. chromium is a heavy metal which is widely used. hexavalent chromium solubility and mobility in aqueous solutions is so high and it is easily reduced. biosorption is a process in which heavy metals are uptake through passive binding by nonliving biomass from aqueous solutions. the present study aimed to determine the capability of powdered sp...

2016
Sumaira Aslam Ali Hussain Javed Iqbal Qazi

We conducted a study for enhanced biological rehabilitation of chromium-contaminated soils using a chromium-reducing and nitrogen-fixing bacterial species (Bacillus megaterium-ASNF3). The bacterial species was isolated from a chromium-rich land area, characterized, and employed under optimum conditions for the treatment of artificially prepared chromium-rich soil. The bacterium reduced Cr(VI) u...

2008
A. Kannan S. Thambidurai

In this study, removal of chromium(VI) from aqueous solutions by Palmyra palm fruit seed carbon (PPFSC) and commercial activated carbon (CAC) was investigated. The metal adsorption capacity has been studied as a function of contact time, pH and carbon dosage. The adsorption yields increased with the increasing of adsorbent dosage and contact time, and subsequently reached the equilibrium. The s...

Journal: :Carcinogenesis 1998
U Werfel V Langen I Eickhoff J Schoonbrood C Vahrenholz A Brauksiepe W Popp K Norpoth

DNA damage (alkaline filter elution) and sister chromatid exchange (SCE) frequencies were measured in lymphocytes of 39 welders and 39 controls. The welders showed a significantly higher rate of DNA single-strand breakages and significantly elevated SCE values. These results are not in accordance with those of a former study in which only DNA-protein cross-links were measured. The different res...

2017
Matthias Weil

Reaction of chromium(III) precursors with TeO2 in PbF2/PbO melts in air led to oxidation of chromium(III) to chromium(VI), whereas tellurium remained its oxidation state of IV. In the resulting title compound, Pb2(CrO4)(TeO3), the two types of anions are isolated from each other, hence a double salt is formed. The two independent Pb2+ cations exhibit coordination number nine under formation of ...

Journal: :محیط شناسی 0
انسیه فدائی کارشناس ارشد محیط زیست، دانشکده منابع طبیعی، گروه محیط زیست دانشگاه بیرجند علیرضا پورخباز استادیار، دانشکده منابع طبیعی، گروه محیط زیست،دانشگاه بیرجند غلامرضا نبی بیدهندی استاد،دانشکده محیط زیست،گروه مهندسی محیط زیست، دانشگاه تهران محمد جواد امیری استادیار، دانشکده محیط زیست، گروه مدیریت و برنامه ریزی محیط زیست، دانشگاه تهران احمد جمشیدی دکتری مهندسی آب، دانشکده عمران، گروه مهندسی آب و محیط زیست، دانشگاه علم و صنعت ایران هادی والهی کارشناس ارشد مهندسی hse، پردیس بین المللی ارس، دانشگاه تهران

chromium (cr) is one of the elements presents in crust of the earth. due to its toxicity, chromium is considered as water contaminant that may disturb metabolic activity. in the present study, adsorption of dissolved chromium (vi) onto elaeagnus angustifolia fruit charcoal, jujube fruit charcoal and the standard granular activated carbon (gac) has been investigated and compared. the effect of c...

2011
P. Kanmani J. Aravind D. Preston

Chromium contaminants emanating from industrial activities pose a significant threat to human’s wellbeing. Chromium (III) and Chromium (VI) are the forms in which they are commonly encountered, of which the trivalent form is relatively benign. Hence, biological reduction of hexavalent chromium has been widely explored by researchers, yielding fruitful outcomes, opening up exciting avenues and a...

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