Wyniki wyszukiwania - AGRO

1

Investigations of sequential extraction of chromium from soil

100%

Kalembkiewicz J., Soco E.

Polish Journal of Environmental Studies

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2002

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tom 11

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nr 3

The sequential extraction of Cr from soil to soil eluates was studied. The influence of conditions of soil sample preparation and conditions of eluates obtained in the final result of Cr extraction from soil and its determination were found. Conditions protecting the total extraction of Cr from soil to solutions were established.

2

Selection of technological variants of sodium chromate [VI] production process with the use of chromic waste

100%

Walawska B., Kowalski Z.

Polish Journal of Environmental Studies

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2000

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tom 09

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nr 2

Various variants of the technological concept of using chromic waste as a substitute of natural raw materials, i.e. chromium ore and dolomite, in the standard process have been proposed. The object (process) function, valid in the researched area, was determined by assuming material balance equations (which describe each of the above-mentioned technological nodes) and by using the relations determined on the basis of experiment results. To work out this function the collections of values characterizing this function and a classification of these values were created.

3

Sequential extraction of chromium from galvanic wastewater sludge

100%

Bielicka A., Bojanowska I., Wisniewski A.

Polish Journal of Environmental Studies

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2005

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tom 14

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nr 2

The sequential extraction of chromium from galvanic wastewater sludge was studied. A five-step sequential fractionation scheme was used to partition the chromium into exchangeable (F I), acid-soluble (F II), reducible (F III), organic matter (F IV) and residual (F V) fractions. The results of investigations indicate that 59.5% of chromium occurred in residual fraction, which is permanently immobilized, whereas 40.5% of chromium in galvanic wastewater sludge can be released to ecosystems under changing natural conditions.

4

The conditions favourable to oxidation of Cr [III] to Cr [VI] and the presence of chromium forms on the area contaminated by tannery wastes

100%

Stepniewska Z., Bucior K.

Folia Histochemica et Cytobiologica. Supplement

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2001

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tom 39

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nr 1

5

Utilization of leather scraps in fertilizer production

100%

Kowalski Z.

Polish Journal of Environmental Studies

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1997

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tom 06

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nr 6

This study applies a new method for utilizing wasted leather scraps after chrome and vegetable tanning. It was found that alkaline hydrolysis with high pressure results in the production of fertilizer solution with N content up to 2.8% and Cr(III) amount lower than 1000 ppm. The method is actually applied.

6

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Soil dehydrogenase activity in the presence of chromium [III] and [VI]

88%

Stepniewska Z., Wolinska A.

International Agrophysics

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2005

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tom 19

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nr 1

7

Chromium analysis in soil

88%

Kalembkiewicz J., Filar L.

Biological Bulletin of Poznań. Supplement

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1996

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tom 33

8

Essentiality of chromium for human nutrition and health

88%

Krejpcio Z.

Polish Journal of Environmental Studies

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2001

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tom 10

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nr 6

The aim of this paper is to review current knowledge about the essentiality of trivalent chromium for animal and human nutrition, and its biological function with special reference to its role in carbohydrate and lipid metabolism, dietary intake and recommendations.

9

Speciation analysis of chromium in waters

88%

Swietlik R.

Polish Journal of Environmental Studies

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1998

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tom 07

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nr 5

The total content of chromium in natural waters does not generally exceed several mg/l. Thus, it is obvious that various forms of chromium will occur at the levels of tenths or hundredths of mg/l. Their determination requires the application of a sufficiently sensitive method, but an important role to play has its specificity in the case of chemical individuals or selectivity in regard to speciation of a group of compounds, e.g. valency states or organic chromium complexes. Generally, however, there is a lack of specific and selective methods, and the concentrations of various forms of the analyte occur often at the level of detection limits of even such sensitive techniques as atomic absorption spectrometry. This paper presents a review of currently available analytical possibilities of chromium speciation investigations in natural water samples. Analytical procedure schemes enabling "total speciation analysis" have been discussed in some detail. A large group of methods used in the speciation analysis of chromium(III) and chromium(VI), both in off-line and on-line mode, has also been discussed.

10

The effect of chromic mud graining on the technological parameters of the sodium chromate production process

88%

Kowalski Z., Fela K., Wieczorek-Ciurowa K.

Polish Journal of Environmental Studies

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2003

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tom 12

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nr 1

The most important solution in the new sodium chromate production process implemented in Alwernia Chemical Works is in-process recycling of chromic mud. This allows lessening the hazard to the natural environment resulting from released chromic waste. It also involves economical advantages. This paper presents studies on the optimisation of this process using of a fuzzy logic method. The influence of the grain size of chromic mud on the sodium chromate production process with chromic mud in process recycling has been estimated. The optimal values of the process parameters can be achieved applying preliminary ground chromic mud and fine-ground fractions of chromic ore. “Deep” milling of chromic mud is not necessary.

11

Chromium speciation in the samples of the 1st water bearing level underground waters subjected to antropopression

88%

Siepak J., Kabacinski M., Baralkiewicz D.

Polish Journal of Environmental Studies

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1996

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tom 05

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nr 2

A method of trivalent and sexivalent chromium speciation in well waters in the city of Poznań was developed. The determinations were performed using atomic spectrophotometric absorption with a graphite cuvette, which involved multiple injection and the CDS (initial tube cooling). The total chromium was determined directly in the collected and acidified samples, while the sexivalent chromium in the extract from a water sample. The extraction was performed using ammonium tetramethylendithiocarbamate (APDC) and methy-isobuthylketone (MIBK) in the presence of a buffer. The trivalent chromium was calculated from the difference between the Cr and Cr(VI). Chromium concentration in underground waters falls between 0.0-5.0 μg/1, with the detection limit for the direct determination method for chromium - 0.01 μg/1. The amount of Cr(VI) ranges from 0.00-1.20 μg/l, with the detection limit for the determination method in extract - 0.01 μg/l.

12

Influence of some factors on chromium occurrence in teeth

75%

Malara P., Kwapulinski J., Drugacz J., Orzechowska-Wylegala B.

Journal of Elementology

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2005

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tom 10

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nr 4 Suppl.1

63

13

Mobilnosc chromu w osadach sciekowych roznego pochodzenia

75%

Gondek K., Filipek-Mazur B.

Acta Scientiarum Polonorum. Formatio Circumiectus

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2003

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tom 02

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nr 1

51-60

14

Determination of adsorption isotherm models for the biosorption of chromium using cherry leaves (Muntingia calabura L.)

75%

Aathithya R., Sowparnika J. R., Balakrishnan V.

International Letters of Natural Sciences

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2014

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tom 20

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.

15

Influence of preparation of rat liver samples on determination of chromium and vanadium using electrothermal atomic absorption spectrometry

75%

Strzyzewski K., Rutkowska M., Iskra M., Baralkiewicz D., Torlinska T.

Journal of Elementology

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2005

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tom 10

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nr 4 Suppl.1

102

16

Effect of chromium on growth, biochemicals and nutrient accumulation of paddy (Oryza sativa L.)

75%

Nagarajan M., Sankar Ganesh K.

International Letters of Natural Sciences

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2014

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tom 18

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.

17

Removal of Cr(III) through bread mold fungus

75%

Shoaib A., Aslam N., Athar M. M., Akhtar S., Nafisa, Khurshid S.

Polish Journal of Environmental Studies

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2013

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tom 22

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nr 4

Cr(III) removal ability of indigenous soil fungus of Pakistan (i.e. Rhizopus arrhizus Fisher) was checked through batch trails. Experiments were performed by taking 0.1 g of powdered fungal biomass in 100 mL of metal solution kept at 150 rpm for 3 hours. Results of FTIR spectroscopy revealed that amine (-NH2) and hydroxyl (-OH) groups participated in Cr(III) binding with the fungal biomass. There was an inversely proportional relationship between adsorption efficiency and capacity on increasing initial metal concentration in the range of 20-100 mg/L. The adsorption capacity of fungal biomass was 43.47 mg/g as determined by Langmuir isotherm. High correlation coefficient (R2: 0.99) acquired through Langumir and Frendulich models adequately described the adsorption mechanism on fungal biomass. pH optimization trials in the range of 2-10 exhibited significantly greater adsorption efficiency of 75% at pH 4, while metal removal rate declined with increasing pH. Adsorption/adsorption trials with four acids indicted that maximum desorption of Cr(III) was found with HCl, followed by HNO3, CH3COOH, and H2SO4. Adsorption-based trials summarized that R. arrhizus is a potential and inexpensive biomaterial with viable application in the removal of Cr(III) from the aqueous solution.

18

Evaluation of thermodynamic properties for the biosorption of chromium by using cherry leaves (Muntingia calabura L.)

75%

Aathithya R., Sowparnika J. R., Balakrishnan V.

International Letters of Natural Sciences

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2014

|

tom 20

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.

19

Kinetic studies for the biosorption of chromium using cherry leaves (Muntingia calabura L.)

75%

Aathithya R., Sowparnika J. R., Balakrishnan V.

International Letters of Natural Sciences

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2014

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tom 20

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.

20

Determination of chromium in soil of Lodz gardens

75%

Jankiewicz B., Ptaszynski B.

Polish Journal of Environmental Studies

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2005

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tom 14

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nr 6

Our work presents the results of the determination of bioavailable and total chromium (III) and chromium (VI) in the soil of an allotment garden situated in the center of Łódź. Chromium was determined by the spectrophotometric method in the form of a purple-red Cr (VI) complex with 1,5-diphenylcarbazide in the acid medium, following the establishment of the optimum amounts of the oxidant (ammonium peroxidisulphate (VI)) in the soil solutions. Moreover, the effects of iron and copper ions on the determination results were examined. For comparison, chromium was also determined by atomic absorption spectrometry.

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