Chemistry Journal of Moldova

Ecological chemistry

EFFECT OF COMPLEX FORMATION ON ELECTROCHEMICAL BEHAVIOUR OF METAL-CONTAINING WASTE WATERS

Author(s):

Olga Covaliova


Field: Ecological chemistry
Type: Research paper
Issue: 2009 Volume 4, no.2
Pages: 34-39
Keywords: electrochemical processes, model plating solutions, ligands, complex salts, polarization curves.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2009.04(2).14

Graphical Abstract:
 The problem of preventing the heavy metals and other toxic substances release in environment due to the discharges of untreated plating and rinsing solutions is actual from both ecologic and economic point of view. It is crucial to prevent the environmental pollution and uncontrolled losses of resources (metals and other substances). The treatment technologies used today are not always efficient and cost saving and in some cases they
may even provoke the secondary pollution of environment. Electrochemical treatment of industrial waste waters is one of the most promising technologies as it implies the same principles as the main technological processes and does not require introducing of chemicals into the treated solution. However, until now this method was given insufficient attention, although there are certain publications in this field [1].

Downloads: 17

REACTIVE EXTRACTION OF TARTARIC ACID

Author(s):

Natalia Marchitan


Field: Ecological chemistry
Type: Research paper
Issue: 2009 Volume 4, no.2
Pages: 28-33
Keywords: reactive extraction, tartaric acid, Amberlite LA-2.
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DOI:
dx.doi.org/10.19261/cjm.2009.04(2).15

Graphical Abstract:
 The present paper describes the results of reactive extraction of tartaric acid in model systems, which can be used for its separation from secondary wine products. As extractant have been used a normal/isododecyl mixed secondary amine Amberlite LA-2. The following parameters of the separation process have been varied: nature of diluent and modifier; modifier concentration; concentration, temperature and pH of the tartaric acid solution and the stirring time, and the work intervals have been established. It was concluded that in determinated conditions the extent of tartaric acid extraction attains value 85-95%.

Downloads: 36

EPITHERMAL NEUTRON ACTIVATION ANALYSIS FOR BACTERIAL TRANSFORMATIONS OF CHROMIUM

Author(s):

N.Ya. Tsibakhashvili, L. Mosulishvili, E. Kirkesali, T. Kalabegishvili, S. Kerkenjia, M.V. Frontasyeva, Gh. Duca , I. Zinicovscaia


Field: Ecological chemistry
Type: Review
Issue: 2009 Volume 4, no.2
Pages: 8-13
Keywords: neutron activation analysis, electron spin resonance spectrometry, Arthrobacter.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2009.04(2).18

Graphical Abstract:
 Most powerful primary analytical technique, neutron activation analysis, was applied to study indigenous bacteria, namely, Arthrobacter genera  which can be successfully used in detoxification and immobilization of toxic substances. In the present study the effect of Cr(VI) on the elemental content of these bacteria has been examined. The concentrations from 12 to 19 elements such as Na, Al, Cl, K, Fe, Co, Zn, As, Br, Rb, Sr, Sb, Ba, Tb, Th, U were determined in the bacterial cells. The high rate of Cr accumulation in the tested bacterial cells was shown. In bacteria treated with  chromate some similarity in the behaviour of the following essential elements − potassium, sodium, chlorine − was observed. Such non-essential elements as Ag, As, Br and U were determined in all bacteria and have to be considered by cells as toxins.

Downloads: 12

SOLUTION OF PROBLEM OF SUPPLYING THE POPULATION WITH QUALITY DRINKING WATER

Author(s):

Goncharuk Vladyslav


Field: Ecological chemistry
Type: Research paper
Issue: 2009 Volume 4, no.1
Pages: 79-83
Keywords: high quality drinking water, supplying of the population, concept.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2009.04(1).08

Graphical Abstract:
 The reasons of poor quality of the drinking water, submitted to consumers have been analyzed. The new concept of supplying the population with high quality drinking water is offered. Qualitative and safe for health drinking water is produced on site of its consumption (using the installations for well-room type). The ways for solving of legislative, organization and technical problems required for realization of the proposed concept are considered.

Downloads: 11

SORPTION OF Cu2+ IONS ONTO DIATOMITE CONSTITUENTS

Author(s):

Vasile Rusu and Aliona Vrinceanu


Field: Ecological chemistry
Type: Research paper
Issue: 2009 Volume 4, no.1
Pages: 75-78
Keywords: diatomite, sorption of Cu2+ ions.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2009.04(1).09

Graphical Abstract:
 Studies of the sorption capacity towards Cu2+ ions of diatomite from the Ghidirim location of RM, as well as of the extracted clay phase are presented. Separated clay fraction from diatomic material is clean enough, and especially is rich in montmorillonite. Maximum sorption capacity for studied clay fraction is achieved by rising the temperature of calcination treatment up to 200oC. At higher temperatures the lattice of montmorillonite is contracted and its sorption capacity towards Cu2+ ions decreases strongly.

Downloads: 16

DETOXIFICATION OF PESTICIDES POLLUTED SOIL BY ADSORBTION ON ACTIVATED CARBONS

Author(s):

V.M. Mukhin, Yu. Ya. Spiridonov, T.G. Lupascu


Field: Ecological chemistry
Type: Research paper
Issue: 2009 Volume 4, no.1
Pages: 72-74
Keywords: pesticides, soil, activated carbon, detoxification.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2009.04(1).10

Graphical Abstract:
 The paper emphasizes a very severe social-ecological problem, related to the contamination of soils by pesticides and fodder micotoxins. The authors suggest the utilization of a carbon adsorption based method of purification of soils contaminated with traces of pesticides. It is demonstrated that this method of soil rehabilitation leads to an 80% crop increase, allowing the production of environmentally clean plant products. The utilization of special activated carbons “Ptitsesorb” leads to a 30-40% decrease of necessary combined fodder in chickens breeding.

Downloads: 33

ADSORPTION OF AMMONIA IONS AND AMMONIUM FROM AQUEOUS SOLUTIONS ON MODIFIED ACTIVATED CARBONS

Author(s):

T. Lupashcu, M. Ciobanu


Field: Ecological chemistry
Type: Research paper
Issue: 2008 Volume 3, no.2
Pages: 55-57
Keywords: adsorption, ammonia ion, ammonia and activated carbon.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2008.03(2).09

Graphical Abstract:
 The adsorption process of ammonia ions and ammonium from aqueous solutions on the intact activated carbon obtained from nutshells through activation with phosphoric acid and oxidized with H2O2 and later impregnated with salt containing Co2+, Ag+, Ni2+, Cu2+, has been investigated. The efficiency of ammonia ions and ammonium elimination from various water categories, using both activated carbon (the intact CAN-7 and CAN-7 oxidized with H2O2 and impregnated with Co2+, Ag+, Ni2+, Cu2+ ions) has been demonstrated.

Downloads: 32

ASPECTS CONCERNING THE PHOTO- AND BIODEGRADATION OF BENZOTHIAZOLES IN AQUATIC COMPARTMENT

Author(s):

A.-M.Delort, P.Besse, G.Mailhot, M.Sancelme, B.Combourieu, Ch.Chorao, O.Covaliova, V.Covaliov, A.Bunescu, I.Dragalin, A.Cincilei, S.Tolocichina


Field: Ecological chemistry
Type: Research paper
Issue: 2008 Volume 3, no.2
Pages: 58-64
Keywords: Photocatalysis, biodegradation, Fenton reagent, immobilized cells, dynamic reactor, active radicals, benzothiazoles, iron, Rhodococcus sp.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2008.03(2).14

Graphical Abstract:
 With the scope to provide complete decomposition of benzothiazoles in water environment, two approaches have been applied including the photocatalytic and biodegradation processes. A new type of continuous-action flow-through photocatalytic reactor was developed, in which it is possible to combine the homogeneous and heterogeneous destruction of refractory organic pollutants. The interactions between the different components of the aminobenzothiazole-containing system under the conditions of photo- and biodegradation (light, iron, free and immobilized bacterial strain Rhodococcus rhodochrous) were analysed. The combined systems “Fe ± light +Rh.rhodochrous” are more effective than simple systems.

Downloads: 12

APPLICATION OF CHEMICAL METHODS TO THE SOLID WASTE MANAGEMENT

Author(s):

C. P. Bulimaga


Field: Ecological chemistry
Type: Review
Issue: 2008 Volume 3, no.2
Pages: 17-29
Keywords: waste, hexacyanoferrates, galvanic wastes, waste from Heat and Power Plants, environmental assessment.
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2008.03(2).17

Graphical Abstract:
 The present article is a synthesis analysis of application of chemical methods for the development of technologies of hazardous waste management. Here are offered some technologies of neutralization of the waste containing hexacyanofferates, galvanic wastes and those with contain of vanadium, which are collected at Power Thermoelectric Plants.

Downloads: 26

STUDY ON QUANTITATIVE SPECIATION, BY BCR METHOD, OF ZINC CONTENT FROM RIVER SEDIMENTS

Author(s):

Georgiana Vasile, Stanescu Bogdan, Tudor Claudia, Elena Mihaila


Field: Ecological chemistry
Type: Research paper
Issue: 2008 Volume 3, no.1
Pages: 56-61
Keywords: sediment, sequential extraction, bioavailability, zinc mobility
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Abstract (JPEG)

DOI:
dx.doi.org/10.19261/cjm.2008.03(1).04

Graphical Abstract: The present work presents the results obtained during investigation of the zinc content of the water and river sediments in an area polluted by mining activities, to provide information on the mobility and availability of this element. Sediment and water samples have been collected from significant sites in a former mining area in which with some sterile pits, which represent a major environmental hazard.

Downloads: 10