Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "hexavalent chromium" wg kryterium: Temat


Wyświetlanie 1-6 z 6
Tytuł:
Use of dead and living fungal biomass for removal of hexavalent chromium
Autorzy:
Holda, A.
Mlynarczykowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/109742.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
hexavalent chromium
Aspergillus niger
biosorption
bioaccumulation
Opis:
The removal of hexavalent chromium from aqueous solution was carried out in batch experiments using dead and living biomass of Aspergillus niger. The effects of the operating parameters such as influent Cr(VI) concentration, influent pH and biomass concentration on the Cr(VI) reduction were investigated. The results indicates that the removal rate of Cr(VI) increased with a decrease in pH or with increase of Cr(VI) and biomass concentrations. For chromium bioaccumulation along with nutrients the process is the most intensive within the first 5 days of mycelium formation. For biosorption, the greatest binding of this metal is achieved within the first 4 days of the process.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 551-563
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Equilibrium and kinetic studies of Cr (VI) removal from synthetic wastewater by Acroptilon repense flower powder
Autorzy:
Ghaneian, M. T.
Ehrampoush, M. H.
Arany, A. M.
Jamshidi, B.
Dehvari, M.
Powiązania:
https://bibliotekanauki.pl/articles/778278.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Acroptilon repens
biosorbent
Hexavalent Chromium
adsorption kinetic and isotherm
Opis:
In this study the removal of Cr (VI) from synthetic wastewater was investigated using Acroptilon repens (Russian Knapweed) flower powder under various conditions (pH, contact time and initial concentration of Cr). The capacity of chromium adsorption at equilibrium conditions by this biosorbent was increased by adsorbate concentration. The results also showed that the removal efficiency of Cr (VI) was increased by increasing the contact time. By increasing the initial concentration of Cr (VI) solution, chromium removal was reduced. The suitability of adsorbents and their constants was tested or evaluated with the Langmuir, Freundlich and Temkin isotherms models. The results indicated that the Freundlich and Langmuir models (R2 > 0.99) gave a better concordance to the adsorption data in comparison with the Temkin equation (R2 = 0.97). The adsorption of Cr (VI) followed the pseudo-second-order kinetics (R2 = 0.991). The study showed that Acroptilon repens flower powder can be used as an effective lignocellulosic biomaterial and biosorbent for the removal of Cr (VI) from wastewater.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 2; 40-47
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Can the effects of chromium compounds exposure be modulated by vitamins and microelements?
Autorzy:
Sijko, Monika
Janasik, Beata
Wąsowicz, Wojciech
Kozłowska, Lucyna
Powiązania:
https://bibliotekanauki.pl/articles/2086573.pdf
Data publikacji:
2021-08-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
zinc
folic acid
selenium
hexavalent chromium
vitamin E
vitamin C
Opis:
Chromium (Cr) is a very common element. It occurs in 2 oxidation states, Cr(III) and Cr(VI). Although Cr(III) is not considered an element essential for mammals, it raises lots of controversy due to its role in the body. While Cr(III) action should be considered an effect of pharmacological action, Cr(VI) is included in the first group of carcinogens for humans. Moreover, it induces numerous pathological changes in the respiratory, urinary, reproductive and digestive systems. In addition, Cr(VI) is used in many industry branches, causing millions of workers all over the world to be exposed to Cr(VI) compounds. A considerable number of the occupationally exposed individuals are in favor of a deep analysis of the mechanisms of Cr(VI) action and a search for a way to reduce its negative impact on the human body. Numerous reactive oxygen species inducing oxidative stress and causing various damage are produced during Cr(VI) reduction in the cells. A good balance between antioxidants and pro-oxidants can reduce Cr(VI)-induced damage. The influence of vitamins and microelements on the adverse Cr(VI) effects has no systematic research results summary. Therefore, this work focuses on the role of dietary antioxidants such as vitamins and microelements in the prevention of Cr(VI) adverse health effects. Numerous studies have revealed a protective influence of vitamins (mainly vitamins E and C) as well as microelements (especially selenium) on the reduction of Cr(VI)-induced adverse changes. A potential protective effect of these ingredients may be useful in occupational groups that are particularly exposed to Cr(VI). However, more research in this area is required.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 4; 461-490
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fate and Management of Pollution of Hexavalent Chromium Cr(VI) and Heavy Metals in the Zarqa River Basin in Jordan
Autorzy:
Shammout, Maisa'a W.
Shatanawi, Muhammad
Awwad, Akl M.
Powiązania:
https://bibliotekanauki.pl/articles/2026728.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
Zarqa River Basin
industrial activity
water pollution
hexavalent chromium
Cr(VI)
heavy metals
decision maker
Opis:
This paper focused on the fate of pollution and management of hexavalent chromium Cr(VI) and heavy metals in the Zarqa River Basin in Jordan. The Zarqa River basin was selected in this research because it contains the majority of Jordanian industries, which are the main source of pollutants including Cr(VI) and heavy metals. This will help in assisting water resource management organizations in decision making when coping with pollution. Industries related to sources and impacts of Cr(VI) and heavy metals were identified, and the administration measures were highlighted according to their role in improving water quality. An analysis of water samples along the Zarqa River was conducted between 2016-2019 to evaluate the heavy metals concentrations and compare the results with the Jordanian standards. Findings showed that Cr(VI) was below the allowable limits (<5 μg/l), and the heavy metals were within the allowed limits set forth in the Jordanian Standard. The ranges of water analysis values (μg/L) were; DO 4640–6480, Fe <40–80, Mn 20–128, Co <20–30, Pb 80–190, Zn 70–100, and Cu <80–190, Al 700–730, V <70–100, B <300–351, Si 1100–1800, Ni 30, and Cd <10. These findings indicated that the quality of the Zarqa River would not cause hazardous effects. However, this was not the case few years ago due the current protection measures. At present some industries have been relocated from the Zarqa Basin to an area that does not pose any environmental hazards, while the rest of industries remained in the basin, but they have established an on-site treatment plant for industrial waste under the control of Jordanian government, and the enforcement of the environmental protection law. These measures must be monitored and updated by decision makers in a sustainable manner to prevent any water pollution.
Źródło:
Journal of Ecological Engineering; 2022, 23, 2; 108-115
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sorption of Cr(VI) onto hdtma modified zeolitic tuffs
Sorpcja Cr(VI) na tufach zeolitowych modyfikowanych HDTMA
Autorzy:
Sobolewska, Paulina
Chojnacka, Maria
Kramski, Dawid
Warchoł, Jolanta
Powiązania:
https://bibliotekanauki.pl/articles/1819520.pdf
Data publikacji:
2020
Wydawca:
Towarzystwo Chemii i Inżynierii Ekologicznej
Tematy:
hexavalent chromium
HDTMA-Br modified zeolites
clinoptilolite
phillipsite
sorption equilibrium
chrom sześciowartościowy
zeolity modyfikowane HDTMA-Br
klinoptylolit
filipsyt
równowaga sorpcji
Opis:
The removal of Cr(VI) from aqueous solutions was investigated using clinoptilolite and phillipsite-chabazite rich tuffs. These minerals were modified using hexadecyltrimethyl – ammonium bromide (HDTMA-Br) and used for Cr(VI) ions removal. The physicochemical characteristics of zeolitic minerals were revealed by XRD, XRF, BET and FT-IR techniques. The uptake capacities of modified zeolites were compared in batch sorption experiments. To predict the sorption isotherms and to determine the characteristic parameters for process design, three isotherm models the Freundlich, the Langmuir, and the Bilangmuir, were applied to experimental data. The data obtained reveal homogeneous Cr(VI) sorption on one kind of active sites on PC-HDTMA surface and heterogeneous sorption on two kinds of active sites on CL-HDTMA surface.
Źródło:
Ecological Chemistry and Engineering. A; 2020, 27, 1-2; 1-9
1898-6188
2084-4530
Pojawia się w:
Ecological Chemistry and Engineering. A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of hexavalent chromium from aqueous solution by adsorption on γ-alumina nanoparticles
Autorzy:
Golestanifar, H.
Haibati, B.
Amini, H.
Dehghani, M. H.
Asadi, A.
Powiązania:
https://bibliotekanauki.pl/articles/207945.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption
alumina
aluminum
chemicals removal
water treatment
chromium
chromium compounds
nanoparticles
sorption
alumina nanoparticles
hexavalent chromium
adsorpcja
aluminium
usuwanie chemikaliów
uzdatnianie wody
chrom
związki chromu
nanocząstki
sorpcja
nanocząstki tlenku glinu
chrom sześciowartościowy
Opis:
The use of γ-alumina (γ-Al2O3) nanoparticles as adsorbent to remove Cr(VI) from aqueous solution was investigated using batch experiments. Adsorption experiments were carried out for various initial doses of Al2O3, initial concentrations of chromium(VI), contact times and pH. The structure and morphology of the sorbent was characterized by XRD, SEM, and TEM techniques. Results demonstrated that the removal efficiency of chromium(VI) was increased by increasing the contact time, initial concentration, and pH. The results of the study showed that adsorption of chromium by γ-alumina nanoparticles reached equilibrium after 60 min and after that a little change of chromium removal efficiency was observed. Furthermore, kinetics of chromium sorption was well fitted by pseudo-second order kinetic model, and well explained by the Freundlich isotherm (R2 > 0.992). Overall, alumina nanoparticles recognized as an effective sorbent to remove chromium(VI) from aqueous solutions.
Źródło:
Environment Protection Engineering; 2015, 41, 2; 133-145
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-6 z 6

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies