Chemistry Journal of Moldova. General, Industrial and Ecological Chemistry

9-19

Authors: Gheorghe DUCA

Nowadays, our human civilization existing on Earth faces a series of top importance challenges that represent direct impact on its existence and development, both industrial and social. All the natural compartments and their components are subjected to the strong and unprecedented anthropogenic influence, including lithosphere, soil, surface and ocean water, atmosphere, vegetal and animal world. Anthropogenic activities has reached such high proportions that provoke the changes in the energy (heat) balance of certain regions and planet as a whole that can affect the climate, increase of water level in oceans and seas, flooding of large areas.

29-36

Authors: Iurie Pinzaru, Tatiana Manceva, Raisa Sircu, Ion Bahnarel, Elena Sanduleac

The incidence and the type of acute chemical poisoning in Republic of Moldova during 2011-2015 were assessed. Records show 22458 cases of poisonings, including 919 death cases. The analysis of poisoning cases involving various types of chemical substances causing the intoxication reveals that the medicines-related poisoning accounts for the highest record of cases (6971), followed by alcohol poisoning (6556 cases); gas poisoning is the third with 1860 cases, and pesticide-related poisoning with 707 cases. Age and gender characteristics of chemical poisonings and ways of exposure to chemicals are discussed.

45-52

Authors: Michal Šereš, Tereza Hnátková, Jan Vymazal, Tomáš Vaněk

Constructed wetlands were proven to be the efficient method for treatment of agricultural wastewaters in last two decades. In this study, the performance of a constructed wetland for treating wastewater from small farm was tested. The constructed wetland for 75 PE with horizontal subsurface flow at Chrámce, Central Bohemian Uplands, Czech Republic, was built in 2011. A hybrid constructed wetland combining the horizontal (HF), vertical filter (VF) and horizontal (HF) filter stages has been designed to treat wastewater from the agriculture production (processing of fruits, sheep, pigs, production of jams, spirits and wine, etc.). The mechanical pretreatment consists of two accumulation tanks (for different wastewater types) from which the wastewater is intermittently pumped into a settling tank. The treatment system consists of two horizontal flow beds and one vertical flow bed with intermittent feeding. The filters are planted with Phragmites australis, Phalaris arundinacea, Iris pseudacorus, Iris sibirica, Glyceria maxima and Lythrum salicaria. For tertiary treatment, three shallow ponds with littoral vegetation were designed. During the feed batch operation the inflow values up to 25.400 mg/L COD and 2.640 mg/L BOD5 were reduced by up to 99%. The volume of each feed batch was applied at one to five day intervals. Also, the effect of discharged water on the littoral zone of aquatic biotopes has been evaluated. This knowledge is necessary for the design of a stable, artificial water system.

61-66

Authors: Narcis Barsan, Valentin Nedeff, Antonina Temea, Emilian Mosnegutu, Alexandra Dana Chitimus, Claudia Tomozei

Development of infrastructure in sewerage systems is essential for improving the living conditions and human health. Considering this situation, research was oriented to the use of a small Sequencing Batch Reactor (SBR) treatment system as a small-scale plant in certain sewers. This type of treatment system was chosen because it can be adapted to the quantitative changes of flows. The most important advantages of SBR process include the possibility of modifying the operating cycle, the elimination of secondary clarifiers and the satisfying control of operations that constitute the treatment. Comparing the problems in Romania and Senegal, regarding wastewater treatment, the present paper aims to identify the best methods and techniques to treat the municipal wastewater in small treatment plants with sequential operation. This paper examines the possibility of using SBR process to treat the municipal wastewater characterized by low flow. This paper also presents a comparative analysis of the degree of purification achieved in a SBR wastewater treatment plant, as well as legislative regulations in Romania and Senegal. Finally, the paper identifies the possible uses of the treated wastewater in different household activities.

74-80

Authors: Olesea Cuzan

The novel N-(methylene-2-pyridine)-N,N-bis(diethoxyphosphorylmethyl)amine ligand (L) was obtained through a double Kabachnik-Fields reaction, starting from 2-(aminomethyl)pyridine (2-picolylamine). Based on the L ligand, a new palladium(II) coordination compound [Pd(L)2Cl2] has been synthesized and comprehensively characterized by spectroscopic methods (1H NMR, UV-Vis), ESI mass spectrometry and X-ray crystallography.

87-94

Authors: Delia-Andrada Duca, Mircea Laurentiu Dan, Nicolae Vaszilcsin

In this paper, the possibility to use ceftriaxone (CEFTR) active compound from expired Cefort® drug as additive in nickel electrodeposition from Watts bath has been investigated. Electrochemical behaviour of CEFTR and preliminary information about its influence on nickel electrodeposition process were obtained using cyclic voltammetry technique. Cyclic voltammograms have been drawn on platinum electrode at scan rates between 5 and 500 mV s-1. Linear voltammograms recorded at low scan rate emphasized the influence of the drug concentration in 5 g L-1 Ni2+ electrolyte solution. Kinetic parameters such as exchange current density and cathodic transfer coefficient have been calculated using Tafel polarization plots at different temperatures in the range of 25÷65°C. Further, activation energy has been determined from Arrhenius plots. Electrochemical impedance spectroscopy technique was used to study the charge transfer resistance and surface coverage degree in the same solutions at different deposition potentials.

102-109

Authors: Andreea-Floriana Enache, Mircea Laurentiu Dan, Nicolae Vaszilcsin

In this paper, anodic oxidation of sulphite ions on platinum nanoparticles modified nickel electrode (Ni–Pt NPs) in aqueous alkaline solution was investigated in order to establish the relationship between kinetic parameters and sulphite concentration. The purpose of this research is both to clarify the oxidation mechanism and to find optimal parameters for sulphite oxidation process using various electrochemical methods. Cyclic voltammetry and linear polarization have been applied to investigate the electrochemical behaviour of sulphite ions and Tafel plots method has been used in order to determine kinetic parameters. To confirm the anodic oxidation mechanism, electrochemical impedance spectroscopy studies have been performed. Furthermore, chrono-electrochemical methods (chronoamperometry, chronopotentiometry, chronocoulometry) have been used in order to obtain more information on sulphite electrooxidation process.

115-118

Authors: Saeid Taghavi Fardood, Ali Ramazani, Sajjad Moradi

Present work involves synthesis of NiO nanoparticles using Arabic gum by the sol-gel method. The synthesized NiO nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM) and X-ray powder diffraction (XRD). It was shown that the synthesized NiO nanoparticles of cubic phase have a spherical shape and an average size of 34 nm.