Ecological chemistry

COMPOSITION OF MINERAL PHASES OF THE GHIDIRIM DIATOMITE

Author(s):

Vasile Rusu, Aliona Vrînceanu and Igor Polevoi

Field: Ecological chemistry
Type: Research paper
Issue: 2007 Volume 2, no.1
Pages: 63-66

Keywords: diatomite, mineralogical composition.
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DOI: dx.doi.org/10.19261/cjm.2007.02(1).13

Graphical Abstract: Studies of the mineralogical composition of diatomite from the Ghidirim location of RM, as well as of the extracted clay phase are presented. The mineral phase of the diatomite contains a number of clay minerals, like montmorillonite (in a mixture with insignificant quantities of slightly chloritized montmorillonite), illite and kaolinite. Diatomite contains also non-clay components as fine-dispersed quartz and amorphous material, the more probable sources of which are opal, amorphous alumosilicates, aluminum and iron hydroxides. The applied procedure for separation of clay fractions by sizing settling in liquid media proves to be very useful, enabling possibilities for more accurate identification of the clay constituents of diatomic material. Procedure allows to separate very clean clay fraction especially rich in montmorillonite, which can be utilized itself as mineral adsorbent for practical purposes.

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USE OF CARBON CATALYSTS FOR OXIDATIVE DESTRUCTION OF WASTEWATERS

Author(s):

Svetlana S. Stavitskaya, Nikolai T. Kartel

Field: Ecological chemistry
Type: Research paper
Issue: 2007 Volume 2, no.1
Pages: 58-62

Keywords: carbon, catalysis, oxidation, destruction, wastewaters.
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Abstract (JPEG)

DOI: dx.doi.org/10.19261/cjm.2007.02(1).14

Graphical Abstract: The paper considers a possibility of using the catalytic action of the carbonaceous adsorbents modified by different ways for the purification of various solutions, natural and wastewaters. It has been found that the oxidative destruction of organic (phenols, dyes, pesticides, etc.) and inorganic (H2S) contaminants in water solutions is considerably intensified in the presence of both ordinary activated carbons and especially, carbons with specially introduced catalytic additives. It is shown that the sewage treatment level is strongly affected by the amount and nature of a modifying agent introduced on the carbon surface.

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STUDIES ON THE WATER SOLUBILIZATION PROCESSES OF OENOTANNINS AND THEIR PHYSICO-CHEMICAL PROPERTIES

Author(s):

Gh. Duca, T. Lupaşcu, P. Vlad, V. Kulciţki, R. Nastas

Field: Ecological chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 60-64

Keywords: physico-chemical properties, water solubilization, oenotannins.
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Abstract (JPEG)

DOI: dx.doi.org/10.19261/cjm.2006.01(1).01

Graphical Abstract: The results of investigation of oenotannins content in the seeds of different grape varieties are presented in the paper. It was demonstrated that the oenotannins content depends on the grape variety as well as on the geographycal zone of grape cultivation. A new procedure for

water sollubilization of oenotannins by depolimerization has been elaborated. The mechanism of the oenotannins depolimerization has been reveiled by mass-spectrometric studies. It has been established, that the depolimerization process brings about formation of carboxilic acids and organic peroxides. The presence of the carboxilic and peroxidic groups was detremined on the basis of

IR spectral analysis. It was demonstrated that the antioxidant properties of modified tannins are higher then those of initial unmodified ones.

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ASSESSMENT OF KINETIC PARAMETERS IN THE WATERS OF THE NISTRU COURSE IN THE SECTION NASLAVCEA – DUBASARI

Author(s):

Elena Bunduchi, Gheorghe Duca, Viorica Gladchi, Nelli Goreaceva, Igor Mardari

Field: Ecological chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 56-59

Keywords: kinetic indicators, hydrogen peroxide, redox state, free radicals, inhibition capacity.
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Abstract (JPEG)

DOI: dx.doi.org/10.19261/cjm.2006.01(1).08

Graphical Abstract: The current work represents the results of a monitoring executed on Nistru River waters between October 2003 and September 2005. The water quality was evaluated on the basis of such kinetic indicators as redox state and capacity of inhibition. The obtained results shows that Nistru River water in the segment Naslavcea village – Dubasari barrage are continuously polluted with reducing substances that diminish the H2O2 content, that actually determines the redox state of natural waters and the content of free radicals.

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DEVELOPMENT OF NATIONAL EMISSIONS FACTORS FOR SOLID WASTEDISPOSAL ON LAND GREENHOUSE GAS SOURCE CATEGORY OF THE NATIONAL INVENTIONAL INVENTORY IN THE REPUBLIC OF MOLDOVA

Author(s):

Tatiana Tugui, Gheorghe Duca, Marius Taranu

Field: Ecological chemistry
Type: Research paper
Issue: 2006 Volume 1, no.1
Pages: 50-55

Keywords: solid waste disposal, greenhouse gas, methane emissions, landfill gas measurements.
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Abstract (JPEG)

DOI: dx.doi.org/10.19261/cjm.2006.01(1).12

Graphical Abstract: The paper summarizes the research results on development national emissions factor for the Greenhouse Gas Inventory (GHGI) Source Category “6A Solid Waste Disposal on Land”. The obtained results offer the opportunity to improve the Intergovernmental Panel for Climate Change (IPCC) methodologies and Emission Factors for assessing the GHG emissions originated from waste sector. The article contains relevant information on composition of landfill gases at managed and unmanaged solid waste disposal sites, as well as the municipal solid waste composition results, investigated during one year in the Republic of Moldova: from autumn, 2004 to summer, 2005.

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Chemistry Journal of Moldova