Search Results

You are looking at 11 - 13 of 13 items for

  • Author or Editor: S. M. Aly x
Clear All Modify Search
Journal of Thermal Analysis and Calorimetry
Authors: A. A. M. Aly, A. S. A. Zidan and A. I. El-Said

The reactions of bis(2-mercaptobenzothiazolato)nickel(H) with some azoles and morpholine afforded the corresponding mixed ligand complexes. The studied azoles were 2-aminothiazole, benzothiazole, benzoxazole, 2-methylbenzoxazole and 2-mercapto-benzoxazole. The formation of new compounds was confirmed from the spectral data. The thermal decompositions of the compounds together with some related compounds reported in the literature, for comparison, were studied. The activation energies and other kinetic parameters were calculated from the Coats-Redfern and Horowitz-Metzger equations.

Restricted access

Summary  

A humin sample, isolated from organic soil (peat) was used to investigate its interaction with different kinds of radioelements in batch systems. The sorption of the radionuclides 110mAg, 60Co and 65Zn by peat humin was studied under different conditions. The results indicated that humin has high ability to sorb the investigated nuclides with the sequence Co2+> Zn2+> Ag+, and can retained up to 1.04 mmol/g of Ag+, 1.63 mmol/g of Zn2+and 1.73 mmol/g of Co2+. The sorption process was time dependent and the percentage of uptake increased with pH to reach a maximum at pH~7.5, which corresponds to the pKavalue of the humin.

Restricted access

Summary  

In a previous paper we studied the interaction of the radionuclides 110mAg, 60Co and 65Zn with peat humin. These nuclides are among the fission or corrosion products in nuclear reactors. The aim of this paper is to study the effect of certain ligands, which are present in the environment, such as humic acid, fulvic acid, EDTA and urea, on the sorption of these radionuclides by humin. The obtained results indicated that urea has no effect on the sorption of Co and Zn by humin, and only a little in case of Ag. However, the presence of the other ligands (humic acid, fulvic acid or EDTA) leads to different decreases in the sorption of the three nuclides by humin. The results are interpreted in the light of the complex formation between ligands and the metal cations and of the strength of binding of these cations to the humin sorbent. The release of Ag+in the presence of different ligands was found to follow the order: humic acid>EDTA>fulvic acid>urea. In the case of both Co2+and Zn2+, the sequence is changed to be: EDTA>humic acid>fulvic acid>urea, with a higher release in the case of Zn2+. The results showed that cobalt is bound more strongly to humin than silver and zinc. The sulphur content of the humic fractions plays a significant role in the competition for silver and zinc.

Restricted access