Search

Co(II), Cd(II) and Rh(III) complexes with 2-(1H-1,2,4-triazol-3-yl)pyridine (Htzp) as ligand were synthesized and investigated. The neutral mononuclear complexes with a generic [M(tzp)n] structure have been prepared from Htzp and corresponding transition metals chlorides at 2:1 and 3:1, respectively molar ratios in H2O–EtOH. The resulted crystalline complexes were investigated through magnetic and molar conductivity measurements, elemental analysis, FT-IR, mass spectroscopy, thermal analysis, UV-Vis and P-XRD. The experiments indicate that Htzp acts as bidentate anionic ligand, [Co(tzp)2]·1.5H2O and [Cd(tzp)2] are in the tetragonal coordination, whereas six coordinate octahedral [Rh(tzp)3]·H2O complex undergoes a weak tetragonal distortion. In case of Co(II) complex, an interesting feature was revealed through fluorescence spectroscopy, as the fluorescent emission intensity of the free ligand is dependent on the Co(II) solution content. Through complexation, the fluorescence is gradually quenched according to the Co(II) aqueous solution content, which may recommend it as a method of detection of Co(II) presence in waste water.

Construction and demolition wastes (C&DW) are usually recognized as not dangerous, but their accumulation can generate serious environmental problems. In spite of C&DW high potential to be reused/recycled, the practical procedures need to be assessed in terms of environmental consequences. The objective of this study is to quantify the environmental impacts of C&DW recycling/reuse, specifically in the production of aggregate 0/30 mm, comparative to those generated during the natural inert processing, in terms of global impacts addressing the whole process and for each technological phase. The analysis was carried out using Life Cycle Assessment methodology, assisted by SimaPro software, and based on primary data collected directly from the Italian Emilia Romagna region. Three methods were used for impact quantification: Eco-Indicator 99, EDIP/UMIP and Cumulative Energy Demand. The analysis revealed that the environmental impacts generated by C&DW recycling/reuse accounting for about 40% of the impacts induced by natural inert processing.

The effect of synthesis conditions on sorptive properties of glycerol-derived mesoporous carbon materials were studied. Sorption properties of the synthesized carbon-based materials regarding to different adsorbate molecules, as well as water vapors, phenol and methylene blue molecules were analyzed. The sorption capacity of the synthesized mesoporous carbons depends upon synthesis conditions, namely upon pyrolyzing temperature and carbon precursor to silica weight ratio, being determined by the nature of the adsorbate molecule and the chemical and structural properties of carbon-based mesoporous material. The templated mesoporous carbons were synthesized using two different glycerol/silica weight ratios (0.5 and 1) and were pyrolyzed at various temperatures (800 degrees C and 1000 degrees C) to study changes in their textural, structural, morphological and chemical surface properties, as well their sorptive properties. The obtained data showed that both considered parameters, glycerol/silica weight ratio and pyrolysis temperature, are important factors in developing the carbon properties. The variation of above mentioned parameters conduct to a progressive deterioration of the carbon structure, associated with structure shrinking and pore walls breaking. Especially significant changes in the structural properties of the studied mesoporous carbon materials occurred for those heated at 1000 degrees C, which manifested themselves in a loss of the total pore volume. It was found that the mesoporous carbons exhibited better thermal stability reflected by the presence of residual mesopores and/or nanostructure ordering. The studies show that the adsorption of methylene blue and phenol onto glycerol-derived mesoporous carbon materials is influenced by their surface chemistry given by the synthesis conditions.

The present research reports the synthesis of poly-N-isopropylacrylamide / mesoporous carbon composites, prepared by radical polymerization of N-isopropylacrylamide inside mesoporous carbon pores functionalized with carboxylic groups. The deposition of poly-N-isopropylacrylamide on mesoporous carbon was confirmed by FT-IR spectroscopy, TEM, N2-sorption measurements. The mesoporous carbon material was found to adsorb vitamin B2 from aqueous solution at room temperature. The obtained composite, poly-N-isopropylacrylamide / mesoporous carbon, exhibited a higher adsorption capacity for vitamin B2 as compared to un-functionalized mesoporous carbon sample, due to hydrogen bonding between carbonyl groups of poly-Nisopropylacrylamide immobilized on the mesoporous carbon surface and amino groups of vitamin B2 molecules.