نتایج جستجو برای: chromium vi extraction

تعداد نتایج: 228606  

ژورنال: سلامت و محیط زیست 2009
افخمی, عباس, رحمانی, علیرضا, صمدی, محمد تقی, نوروزی, رقیه,

Background and Objectives:Groundwater treatment by nano particles has received increasing interest in recent years. Chromium is a commonly identified contaminant in soils and groundwater. Zero-valent iron, as a natural reduction agent can be used in controlling of contaminated sites. The aim of this research is investigation of hexavalent chromium removal from aqueous solutions by using of iron...

2013
Bhaswati Chakraborty Suvendu Indra Ditipriya Hazra Rupal Betai Lalitagauri Ray Srabanti Basu

Organic pollutants, like phenol, along with heavy metals, like chromium, are present in various industrial effluents that pose serious health hazard to humans. The present study looked at removal of chromium (VI) in presence of phenol in a counter-current continuous packed bed reactor packed with E. coli cells immobilized on clay chips. The cells removed 85% of 500 mg/L of chromium (VI) from MS...

Journal: :The Annals of occupational hygiene 1979
M Bohgard B L Jangida K R Akselsson

A method is described for assessing occupational exposures to chromium aerosols; it involves four procedures. The first, proton induced X-ray emission (PIXE), measures the total chromium. The second, electron spectroscopy for chemical analysis (ESCA), measures the oxidation state of the particle surfaces, and the third, which uses sym-diphenylcarbazide (DPQ, measures the proportion of water-sol...

Journal: :Occupational and environmental medicine 2015
Roberta Welling James J Beaumont Scott J Petersen George V Alexeeff Craig Steinmaus

OBJECTIVES Chromium VI (hexavalent chromium, Cr(VI)) is an established cause of lung cancer, but its association with gastrointestinal cancer is less clear. The goal of this study was to examine whether the current human epidemiological research on occupationally inhaled Cr(VI) supports the hypothesis that Cr(VI) is associated with human stomach cancer. METHODS Following a thorough literature...

Journal: :Journal of environmental quality 2007
Ioannis Ipsilantis Mark S Coyne

Theories suggest that rapid microbial growth rates lead to quicker development of metal resistance. We tested these theories by adding hexavalent chromium [Cr(VI)] to soil, sowing Indian mustard (Brassica juncea), and comparing rhizosphere and bulk soil microbial community responses. Four weeks after the initial Cr(VI) application we measured Cr concentration, microbial biomass by fumigation ex...

2013
M. K. MICHAILIDES A. G. TEKERLEKOPOULOU C. S. AKRATOS

Scientific interest on chromium removal from water and wastewater has escalated recently. Chromium compounds exist in the environment naturally but are mostly found due to anthropogenic activities (tanning, paint, cement industries, etc.). Hexavalent chromium [Cr(VI)] is of major environmental importance because it is one of the most stable chromium forms found in the environment. It is soluble...

2014
Yu-Hsuan Lee Shih-Bin Su Chien-Cheng Huang Hamm-Ming Sheu Jui-Chen Tsai Chia-Ho Lin Ying-Jan Wang Bour-Jr Wang Yu-Jia Chang

Chromium hypersensitivity (chromium-induced allergic contact dermatitis) is an important issue in occupational skin disease. Hexavalent chromium (Cr (VI)) can activate the Akt, Nuclear factor κB (NF-κB), and Mitogen-activated protein kinase (MAPK) pathways and induce cell death, via the effects of reactive oxygen species (ROS). Recently, cell death stimuli have been proposed to regulate the rel...

Journal: :Journal of environmental management 2010
Saidur Rahman Chowdhury Ernest K Yanful

Adsorption of arsenic and chromium by mixed magnetite and maghemite nanoparticles from aqueous solution is a promising technology. In the present batch experimental study, a commercially grade nano-size 'magnetite', later identified in laboratory characterization to be mixed magnetite-maghemite nanoparticles, was used in the uptake of arsenic and chromium from different water samples. The inten...

Journal: :Environmental Health Perspectives 1998
J W Hamilton R C Kaltreider O V Bajenova M A Ihnat J McCaffrey B W Turpie E E Rowell J Oh M J Nemeth C A Pesce J P Lariviere

Certain forms of the heavy metals arsenic and chromium are considered human carcinogens, although they are believed to act through very different mechanisms. Chromium(VI) is believed to act as a classic and mutagenic agent, and DNA/chromatin appears to be the principal target for its effects. In contrast, arsenic(III) is considered nongenotoxic, but is able to target specific cellular proteins,...

Journal: :Analytical sciences : the international journal of the Japan Society for Analytical Chemistry 2005
Saad S M Hassan M S El-Shahawi A M Othman M A Mosaad

The construction and performance characteristics of a novel chromate ion-selective membrane sensor are described and used for determining chromium(III) and chromium(VI) ions. The sensor is based on the use of a rhodamine-B chromate ion-associate complex as an electroactive material in a poly(vinyl chloride) membrane plasticized with o-nitrophenyloctyl ether as a solvent mediator. In a phosphate...

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