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Wyszukujesz frazę "chromium" wg kryterium: Temat


Wyświetlanie 1-7 z 7
Tytuł:
Kinetic studies for the biosorption of chromium using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/10873.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
kinetics
biosorption
chromium
cherry
leaf
Muntingia calabura
Opis:
Biosorption is an attractive technology which is used for the sorption of substances by a biomaterial. In this present work the heavy metal chromium was subjected to biosorption because of their non-degradability nature and causes water and land pollution. Cherry leaves were used as a biomaterial for the biosorption. Kinetic studies were performed for the biosorption experiment. From the experiment it was found that the reaction follows pseudo first order reaction because of the larger value of regression coefficient R2 and lower value of standard errors (χ2) for pseudo first order reaction than second order reaction.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of thermodynamic properties for the biosorption of chromium by using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/11897.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
thermodynamic property
biosorption
chromium
cherry
leaf
Muntingia calabura
entropy
Opis:
Chromium is a heavy metal which has widely used in tannery and electroplating industries. Contaminations of these industrial metals into the river possess major threat to an environment. Therefore, biosorption is a technique which is applied for the sorption of heavy metal by a biomaterial. In the present study reveals that cherry leaves was used as a biomaterial and for that the thermodynamic properties was evaluated for the biosorption of chromium. From the thermodynamic studies it was found that the reaction was feasible, spontaneous and exothermic because the values of ΔG = negative, ΔS = negative and ΔH = positive. So, it was concluded that the experiment was thermodynamically feasible.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of chromium by biosorption method (chitosan)
Autorzy:
Abatneh, Y.
Sahu, O.
Powiązania:
https://bibliotekanauki.pl/articles/11428.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
removal
chromium
biosorption
chitosan
absorbent
polymer
water
rheological measurement
Opis:
Discharge of metal containing effluents into water has been a cause of major concern. Traditional treatment methods are proving to be ineffective and expensive. Chitosan was studied as a potential biosorbent due to its positive charge and relatively low cost. The study involves evaluating the metal binding performance of chitosan in a Polymer Enhanced Diafiltration (PEDF) system which uses an ultra filtration membrane to retain the chitosan which, in turn, binds the metal, thereby preventing passage into the permeate stream. Conditions for binding such as pH, concentration of polymer and chromium were studied. Optimal performance was obtained when the system was operated at pH values lower than the pKa of chitosan i.e. 6.3. Using 6 g/L chitosan at pH 4.0, chromium concentration was reduced to less than 1mg/L from a feed concentration of 20 mg/L. Equilibrium dialysis experiments were done to study the kinetics of binding and the uptake of metal per gram of polymer. Rheological measurements demonstrated that in the presence of 1-100 mM chromate, chitosan was found to be slightly shear thickening at low concentrations such as 4 g/L and 6 g/L whereas it was slightly shear thinning at higher concentrations like 12 g/L and 20 g/L This suggests that neutralization of chromium anions is due to the interaction of multiple chitosan molecules. This result is consistent with the relatively stiff nature of the polysaccharide. Overall, this study suggests that some modification of the native polymer would be required to improve uptake and make it an industrially workable process.
Źródło:
International Letters of Natural Sciences; 2014, 03
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of adsorption isotherm models for the biosorption of chromium using cherry leaves (Muntingia calabura L.)
Autorzy:
Aathithya, R.
Sowparnika, J.R.
Balakrishnan, V.
Powiązania:
https://bibliotekanauki.pl/articles/11799.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
determination
adsorption isotherm model
biosorption
chromium
cherry
leaf
Muntingia calabura
Opis:
Contaminations of industrial metals into the river possess major threat to environment. Chromium is a heavy metal which has the wide applications in tannery and electroplating industries. Above the permitted level of Chromium(VI) into surface water leads to severe health hazards. Therefore, biosorption is a technology used for the sorption of heavy metal. In this present study adsorption isotherm models was studied for the biosorption of chromium by cherry leaves. From the adsorption isotherms it was found that the experimental data fits well with the Langmuir isotherm than the Freundlich isotherm. The monolayer capacity Qm was fond to be 11.98 mg/l and the adsorption affinity was found to be positive which indicates the efficient biosorption of chromium.
Źródło:
International Letters of Natural Sciences; 2014, 20
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of chromium on growth, biochemicals and nutrient accumulation of paddy (Oryza sativa L.)
Autorzy:
Nagarajan, M.
Sankar Ganesh, K.
Powiązania:
https://bibliotekanauki.pl/articles/11254.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
chromium
heavy metal accumulation
plant growth
nutrient
paddy
Oryza sativa
Opis:
Chromium is a heavy metal; this element is considered as an environmental hazard. Toxicity effects of chromium on growth and development of plants including inhibition of germination process decrease of growth and biomass of plant. The aim of this research is to study accumulation of Chromium along with nutrients and its effect on the growth of Paddy plant (Oryza sativa L). Thus, paddy seedlings grown in petriplates lined with filter paper undergoing, different treatments of Cr (0, 2.5, 5, 10, 25, 50, 75, 100 and 200 mg/L). After one week seedlings were removed and morpho physiological parameters like root length, shoot length and dry weight of plants and Biochemicals ,accumulation of nutrients along with Cr in roots and shoots were determined. The results indicated that the concentrations more than 100 mg/L chromium cause the reduction of morphophysiology parameters in the treatment plants rather than control plant and Cr addition in the cultures caused enhancement of chromium content in roots and shoots of plant seedlings. Similarly the biochemicals and nutrient accumulation also affected by increasing concentrations of chromium. It was also noted that accumulation of chromium in the roots was much higher than the shoots of the seedlings under treatment.
Źródło:
International Letters of Natural Sciences; 2014, 18
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ecophysiological and biochemical changes in Abelmoschus esculentus (L.) Moench under chromium stress
Autorzy:
Unnikannan, P.
Vedhanarayanan, P.
Sundaramoorthy, P.
Powiązania:
https://bibliotekanauki.pl/articles/10841.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
ecophysiological change
biochemical change
Abelmoschus esculentus
bhendi
chlorophyll content
mineral nutrient
chromium stress
biochemical parameter
Opis:
Increasing concentrations of chromium caused reduction in growth, chlorophyll contents and mineral mutrients of bhendhi. At increasing concentrations of chromium, all the attributes were found to be reduced. Chromium is one of the toxic elements discharging from tannery industry. The long disposal of tannery effluent to the agricultural land causes serious damages in the soil texture; reduce the growth of microorganisms and agricultural crops. Large areas of Vellore district of Tamilnadu was seriously affected by the tannery effluent irrigation to the agricultural land. The present study was conducted to identify the phytotoxic effect and physiological changes of Abelmoschus esculentus (L.) Moench under the treatment of different concentrations of chromium solutions (2.5, 5, 10, 25, 50, 75 and 100 mg/l). The result shows that there was a gradual reduction in the morphological parameters (root length, shoot length, fresh weight and dry weight). Similarly the photosynthetic pigments (Chlorophyll and carotenoid) and biochemical parameters such as protein, amino acid, and sugars were also gradually decreased with increasing concentrations of chromium.
Źródło:
International Letters of Natural Sciences; 2014, 02
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chromium toxicity in Sesbania sesban (L.) Merr
Autorzy:
Bakiyaraj, R.
Mahakavi, T.
Baskaran, L.
Powiązania:
https://bibliotekanauki.pl/articles/10775.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
chromium
toxicity
Sesbania grandiflora
pot experiment
toxic effect
plant
germination
chlorophyll
enzyme
metal accumulation
seedling
shoot
Opis:
Chromium is one of the most common toxic metals present in the environment that induces various toxic effects in plants. A pot experiment was conducted to determine the effects of chromium on germination percentage, seedling growth, chlorophyll ‘a’, ‘b’ and proline content of Sesbania sesban (L.) Merr. The seedlings were treated with different concentrations of control, 0.10, 0.25, 0.50, 0.75 and 1.00 g kg-1 of chromium. The parameters such as germination percentage, root and shoot length, seedling fresh weight dry weight, chlorophyll ‘a’, ‘b’ and proline content of leaves were measured. Our results indicated that a significant inhibitory effect was observed at all levels of chromium compared to control. Increasing the concentration of chromium to 1.00 g kg-1 showed a significant decrease in seed germination, shoot and root length, fresh weight, dry weight and chlorophyll ‘a’ and ‘b’ content of plant. While proline, catalase and peroxidase contents were increased by increasing Cr concentration. It was also noted that accumulation of chromium in the roots was much higher than the shoots of the seedlings under treatment.
Źródło:
International Letters of Natural Sciences; 2014, 04
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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