Chemistry Journal of Moldova

Abstract (JPEG)

DOI: dx.doi.org/10.19261/cjm.2011.06(1).01

Graphical Abstract: The increasing contamination of soil, sediment, and water with heavy metals by natural and industrial processes is a worldwide problem. Many bacteria and microalgae have demonstrated ability to absorb toxic elements. To study mercury biosorption by bacteria Arthrobacter globiformis and microalga Spirulina platensis neutron activation analysis (NAA) was applied. The process of mercury biosorption by these media was described by Freundlich and Langmuir-Freundlich Model. Both microorganisms showed a great potential to be used as biosorbing agents for mercury removal from the environment.


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DOI: dx.doi.org/10.19261/cjm.2010.05(2).04

Graphical Abstract: The intact activated carbon CAN-8, obtained from nutshells by activation with water vapours, in the presence of oxygen and at relatively low temperatures, possesses catalytic activity, caused by the presence of alkaline functional groups on its surface, as well as by the formation, in these experimental conditions, of the OH radical, which has a high oxidation potential. After 25 cycles of the process of methylene blue oxidation, the data of chromatographic analyses indicate the presence of three organic components in the solution.


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DOI: dx.doi.org/10.19261/cjm.2010.05(2).05

Graphical Abstract: The old pesticide storages in Moldova showed a large quantity of polluted sites. The inventory of POPs polluted sites showed a huge number of extra high polluted sites (more 50,0 mg/kg) which need the first place a remediation or other action to eliminate direct contact with people and animals. The pollution spectrum of POPs is a complex and consists of five groups: DDTs isomers, HCHs isomers, Toxaphene mixture, Chlordane and Heptachlor. The principal groups among these substances are DDTs and HCHs isomers.


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DOI: dx.doi.org/10.19261/cjm.2010.05(1).06

Graphical Abstract: Nitrification is the oxidation of ammonia to nitrate, via nitrite and it occupies a central position within the global nitrogen cycle. Nitrifying bacteria are the organisms capable of converting the most reduced form of nitrogen, ammonia, to the most oxidized form, nitrate, but their activity is influenced by pollution level. Starting with the assumption that pollution of small internal water courses in the Republic of Moldova remained severe (phenols, detergents and copper regularly exceed the MACs) the work presented in the paper discusses the evolution of ammonia ions nitrification in the water of river Prut tributaries and its correlation with the content of pollutants in water: surface-active substances, Cu, BOD5, COD and other compounds.


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DOI: dx.doi.org/10.19261/cjm.2010.05(1).07

Graphical Abstract: As sources of water supply in the Republic of Moldova underground waters constitute 15,2% (bore holes, springs and wells). The present work includes water quality investigations and aims to reveal local sources in river Nistru hydrographic basin (Rezina district) for drinking water provision in villages. Chemical composition of investigated spring’s water shows that in Rezina district 19% of springs are polluted with nitrogen compounds. Water of only 9% of springs is in conformity with the standard for drinking water. Water from 102 springs meets the requirements of irrigation that doesn’t present the risk of soil salinization (K > 18) – 1 383 L/min.


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DOI: dx.doi.org/10.19261/cjm.2011.06(2).12

Graphical Abstract: It was proved the possibility of determination the total potassium in soils by gamma-spectroscopic method with subsequent calculation of total potassium content in according to value of 40K isotope (expressed in Becquerel, Bq), using the formula:
К2О, % = С . А, where: C – conversion coefficient, A – activity of isotope 40K in soil, Bq/kg. Conversion coefficient for chernozems of Moldova – C=0,00337.


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DOI: dx.doi.org/10.19261/cjm.2011.06(2).13

Graphical Abstract: The compound Enoxil is a mixture of polyphenols, esthers, and carboxylic acids, which could be involved in reducing the risk of diseases associated with oxidative stress. The results of the investigation of antioxidant activity for the compound Enoxil and its forms are presented in this paper. It can be concluded that acetone-Enoxil has a higher antioxidant activity that other tested compounds.


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DOI: dx.doi.org/10.19261/cjm.2011.06(1).07

Graphical Abstract: It was established that the process of catalytic oxidation of methylene blue, at low concentrations (20 mg/L), i.e. in real solutions, gives sulfates and nitrates and new product, which can be categorized, in their vast majority, as impurities, probably got from the vacuum distillation unit, which make up for only ~ 10 % of methylene blue used in the experiment. Methylene blue adsorption at the interface occurs in real solutions. In case of performing the process at methylene blue concentration of 120 mg/L, hemi-micelles are adsorbed at the interface and the OH• radical acts more effectively due to the presence at the interface of a greater number of dye molecules.


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