نتایج جستجو برای: chromium (vi) extraction

تعداد نتایج: 228606  

2017
Barbara Leśniewska Marta Gontarska Beata Godlewska-Żyłkiewicz

A critical appraisal of single-step extraction procedures of chromium species from soil was done in terms of their selectivity towards Cr(III) and Cr(VI) species. Samples of natural mineral and organic soil and samples of soil enriched with different chromium compounds of various solubility (in liquid or solid form) were used to simulate contamination of soil by liquid and solid wastes. The eff...

Journal: :international journal of environmental research 2010
v. eyupoglu b. eren e. dogan

artificial neural networks (anns) are computer techniques that attempt to simulate the functionality and decision-making processes of the human brain. in the past few decades, artificial neural networks (anns) have been extensively used in a wide range of engineering applications. there are only a few applications in liquid membrane process. the objective of this research was to develop artific...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2003
A Ouejhani M Dachraoui G Lalleve J F Fauvarque

A method is introduced for recuperation of chromium(VI) in water samples by liquid-liquid extraction with tributylphosphate PO(C4H9O)3 (TBP) from acidic chloride media. The optimum conditions for quantitative extraction of Cr(VI) were evaluated by varying the experimental parameters, such as the shaking period, the pH of the aqueous phase, the hydrochloric acid concentration, the hydrogen and c...

2010
HARI HARAN

Chromium (VI) Considered as a serious health hazard and it has attracted attention as a pollutant in natural waters. The sources of contamination of chromium in natural waters and in the Environment are from electroplating, tanning industries and waste solution from oxidative dyeing and leaching from sanitary land – fills, In view of this the separation and determination of chromium has been re...

2015
Hamid Shirkhanloo Aisan Khaligh Farideh Golbabaei Zargham Sadeghi Amir Vahid Alimorad Rashidi

BACKGROUND Chromium (VI) has toxic and carcinogenic effects. So, determination and speciation of chromium in environmental samples is very important in view of health hazards. In this study, solid phase extraction (SPE) based on bulky amine-functionalized bimodal mesoporous silica nanoparticles (NH2-UVM-7) as a novel nanoadsorbent was applied for preconcentration and speciation of chromium (III...

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...

2003
A. V. L. N. S. H. HARIHARAN

The extraction of chromium (VI) from hydrochloric, hydrobromic, and acetic acid solutions with Tri caprylamine oxide (TCAO) in benzene has been studied. The extractions from hydrochloric and hydrobromic, acid solutions are nearly quantitative and are partial from acetic acid solutions. The optimum conditions for extraction were established from the study of the effect of several variables like–...

Journal: :Journal of hazardous materials 2009
L Hua Y C Chan Y P Wu B Y Wu

Toxicity of hexavalent chromium (Cr(6+)) was focused on with a publication of EU RoHS directive, a novel method to determine hexavalent chromium is developed. It is a combination of energy dispersion X-ray fluorescence spectrometry (EDXRF), spot test, alkali digestion and UV-vis spectrophotometric analysis. First, by EDXRF screening, the presence or absence of element Cr was established. Spot t...

Darvishmotevalli1, Mohammad , Dehghanifard, Emad, Noorisepehr, Mohammad, Noroozi, Roghayeh,

Introduction: Aerobic granules as a novel type of bio-sorbent have an excellent settling ability and high-porosity structure. This study investigated the feasibility of aerobic granules for chromium (VI) removal from synthetic aqueous solution and compare it with conventional activated sludge. Method: In this research the effect of some important parameters including pH (5, 7, and 9), initial c...

2016
Tsvetomil VOYSLAVOV Stefan TSAKOVSKI Sonya GANEVA

A fast, simple, and reliable method for determination of hexavalent chromium species in soil aqueous and alkaline extracts has been developed. The procedure is based on the ion-pair extraction of Cr(VI) with methyltrioctylammonium chloride (Aliquat 336) into xylene. The extract is analyzed by flame (FAAS) or electrothermal atomic absorption spectrometry (ETAAS). The method allows the detection ...

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