Chemistry Journal of Moldova

 
https://doi.org/10.19261/cjm.2024.1237

Graphycal Abstract: This study assessed water quality in Cișmea, Orhei district (coordinates 47°24’56.0"N 28°45’05.9"E). Surface and underground water were analyzed for pH, conductivity, hardness, chloride, sulfate, and chemical elements. The concentration values of the 36 elements determined by the ICP-OES method are presented. Conductivity and sulfate deviations indicated high dissolved solids. Results revealed significant deviations from permissible levels: As (1.7-1.9x), Cd (3.4-3.5x), Pb (1.2-2.3x), Na (1.2-4.0x), and B (1.6-3.3x). Notably, Ba, Tl, and Bi concentrations were also detected. 




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https://doi.org/10.19261/cjm.2024.1196





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https://doi.org/10.19261/cjm.2024.1144

Abstract (PDF)
Graphical Abstract: This study examines the potential use of a low-cost biosorbent - chamomile tea residues, as an alternative to traditional adsorbents for removing Pb²⁺ ions from aqueous solutions. The results show that lead concentration is reduced under optimized conditions, achieving an impressive nearly 50% Pb²⁺ ions removal with a mere just 0.05 g of the waste material, depicting chamomile tea residues as efficient biosorbent in lead removal.



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https://doi.org/10.19261/cjm.2024.1113

Abstract (PDF)
Graphical Abstract: This study explores the green synthesis of silver and zinc nanoparticles using Laurel extract as a reducing agent. The biosynthesized nanoparticles were characterized for size, shape, and structure. Photocatalytic activities were evaluated for potential environmental applications. Results show promising prospects for sustainable nanoparticle synthesis and efficient photocatalytic degradation.




Downloads: 536

 
https://doi.org/10.19261/cjm.2023.1091

Abstract (PDF)
Supplementary Material (PDF)
Graphical Abstract: The aim of this research work was to evaluate the role of different fractions of humic substances in the binding of Al(III), Fe(III) and Cu(II) ions into complexes. The share of humic substances with a molecular weight of 20–5 kDa increases from 37% to 59%, when the total concentration of humic substances also increases. It was established that humic substances with molecular weight 20–5 kDa bounded the smallest amount of Al(III), Fe(III) and Cu(II) into complexes.




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https://doi.org/10.19261/cjm.2023.1019

Abstract (PDF)
Graphical Abstract: The degradation of diisopropyl methylphosphonate (DIMP) in aqueous solutions was studied using ultrasound irradiation with a fixed frequency of 26.6 kHz, following the first-order kinetic model. The experimental parameters, including the pH, the initial concentration of DIMP, the processing time, and the concentration of the additive CCl₄ were investigated. The best degradation efficiency of 98% was observed at pH of 10, adding 0.8 g/L CCl₄ for a processing time of 45 min.





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Downloads: 114

https://doi.org/10.19261/cjm.2023.924

 

Downloads: 177

https://doi.org/10.19261/cjm.2023.910

Abstract (PDF)
Graphical Abstract: This paper presents the synthesis of a copolymer with reducing properties obtained by functionalizing chitosan with quercetin and determining the antioxidant activity of the derivatives obtained depending on the molar mass of the polymer. For this purpose, low molecular weight chitosan was obtained by oxidizing industrial chitosan with hydrogen peroxide and functionalizing with quercetin by the covalent grafting method. The comparative antioxidant properties of the composite obtained by grafting technical chitosan with quercetin and by grafting low molecular weight chitosan were studied by the DPPH (2,2-diphenyl-1-picrylhydrazyl radical) method. The obtained results indicate that a decrease in the molecular weight of chitosan contributed to its grafting with quercetin. As a result, the functionalized polymer composite acquired a higher antioxidant activity and can be successfully used to inhibit the oxidation of various organic substrates in the cosmetic, food and pharmaceutical industries. 





Downloads: 146

https://doi.org/10.19261/cjm.2023.1049






Downloads: 99