Ahmed M. Donia

Effect of structural properties of acid dyes on their adsorption behaviour from aqueous solutions by amine modified silica

Monoamine modified silica particles (MAMS) were prepared and characterized by infrared (FT-IR) and thermogravimetric analysis (TGA). The modified silica particles were used for removal of acid orange 10 (AO-10) and acid orange 12 (AO-12) from their aqueous solutions. The adsorption behaviour of the two dyes was studied at different experimental conditions of pH, contact time, concentration of dye, temperature and salt solution. The adsorption of AO-10 followed pseudo-first order kinetics whereas AO-12 followed pseudo-second order. The two dyes showed different modes of interaction with silica surface. Desorption of the loaded dyes was carried out at pH 10 and found to be 10.4 and 91.6% for AO-12 and AO-10, respectively.

Synthesis of amine and thio chelating resins and study of their interaction with zinc(II), cadmium(II) and mercury(II) ions in their aqueous solutions

Chelate forming resins containing amino and thio groups have been prepared. The interaction of the obtained resins with Zn(II), Cd(II) and Hg(II) from their aqueous solutions was studied. The metal ion uptake behaviour and selectivity of the resins towards the metal ions were investigated by both batch and column methods. Hg(II) showed higher affinity towards the amino and the thio resins compared to Zn(II) or Cd(II). The mechanism of interaction between the resin and the studied metal ions could be explained on the basis of the formation of resin–metal complex in neutral conditions. In mediums acidified by HCl, the interaction of Hg(II) was interpreted to proceed via ion-exchange mechanism. Hg(II) could be separated from Cd(II) in acidic medium. The studied resins were regenerated using HNO3 or acidified thiourea. It was not recommended to use HCl for elution of Hg(II) from the loaded resins due to its affinity for interaction with resins via ion-exchange.

Studies on uptake behaviour of copper(II) and lead(II) by amine chelating resins with different textural properties

Glycidyl methacrylate resins with different ratios of divinylbenzene as cross-linking agent have been prepared. The textural properties such as density, porosity, pore area and pore diameter of the resins obtained were elucidated. The resins were anchored by chelating amino groups through the treatment with ethylenediamine (en). The amino group concentration on the resins was determined. The uptake behaviour of Cu(II) and Pb(II) from their aqueous solutions by the resins was studied. Both uptake capacity and selectivity of the resins towards the studied metal ions were discussed in terms of amino group concentration as well as the textural properties. The study indicated that metal-resin interaction proceeds via surface and diffusion mechanisms. The pH 5.8 found to be the most suitable for the uptake of the investigated metal ions. Copper was selectively separated from lead (using resin RI-en). The studied resins showed good durability and regeneration using HNO3.

Effect of Chain Length of Aliphatic Amines Immobilized on a Magnetic Glycidyl Methacrylate Resin towards the Uptake Behavior of Hg(II) from Aqueous Solutions

Abstract Magnetic resin particles with magnetite (Fe3O4) core and glycidyl methacrylate/divinylbenzene resin shell were prepared. The core‐shell particles obtained were immobilized with ethylenediamine, diethylenetriamine, or tetraethylenepentamine to give resins with names, R‐1, R‐2 and R‐3, respectively. These resins showed good magnetic properties and could be easily retrieved from their suspensions using an external magnetic field. The uptake values of resins towards Hg(II) were found to be 2.1, 3.2, and 4.8 mmol/g for resins R‐1, R‐2, and R‐3, respectively. The effect of chain length as well as the content of amine sites on the uptake behavior was studied at different temperatures. The values of kinetic and thermodynamic parameters of the uptake process were reported. These values reflected the effective role of amine type and chain length on both the rate of uptake and the maximum capacity of the resins. Moreover, the column studies showed that the longer the amine chain was the shorter was the critical bed height.

Complexes of manganese(II), cobalt(II) and nickel(II) with the keto form of some antipyrine schiff base derivatives

Abstract Manganese, cobalt and nickel complexes of some Schiff base derivatives of antipyrine have been prepared and characterized. Spectroscopic and other studies on these air-stable complexes indicated that the Schiff bases are coordinated through the carbonyl oxygen of the pyrazolone ring, the quinonoid oxygen and the secondary nitrogen. The stereochemistry of the complexes as well as the nature of the bonding of the chloride were discussed.

Reversible and irreversible thermochromism of some Schiff base metal complexes

SummaryNickel(II) and copper(II) complexes of Schiff bases derived from salicylaldehyde, 2-hydroxy-1-naphthaldehyde, 2,4-dihydroxybenzaldehyde, 2,3-dihydroxybenzaldehyde or 5-chlorosalicylaldehyde and 8-aminoquinoline have been prepared and characterized. Several of the complexes are thermochromic in the solid state. The origin of the thermochrornism is discussed in terms of changes in ligand field strength and coordination geometry. These changes were studied by means of thermal and spectral methods.

Fast kinetic and efficient removal of As(V) from aqueous solution using anion exchange resins.

Glycidyl methacrylate/methelenebisacrylamide resin with immobilized tetraethylenepentamine ligand was prepared. This pentamine containing resin was transformed to two anion exchange resins through treatment by glycidyl trimethylammonium chloride to give (RI) or hydrochloric acid giving (RII). The resins were used to adsorb As(V) at different experimental conditions using batch and column methods. Kinetics and thermodynamic properties as well as the mechanism of interaction between As(V) and resin active sites were discussed. The maximum adsorption capacities of As(V) on RI and RII were found to be 1.83 and 1.12 mmol/g, respectively. The regeneration and the durability of the loaded resin towards the successive reuse were also investigated.

SYNTHESIS, IDENTIFICATION AND THERMAL ANALYSIS OF COPRECIPITATES OF SILVER-(COBALT, NICKEL, COPPER AND ZINC) OXALATE

Abstract The coprecipitates Ag2M(C2O4)2 · nH2O (M  CO2+, Nit2+, Cue2+ or Zn2+) have been prepared and identified by means of IR, elemental analysis, XRD, SEM and (DTA/TGA). The XRD and SEM data indicate that, the coprecipitates are solid solutions. The thermal decomposition of the compounds in dynamic air and N2 flow has been studied. It is established that, the atmosphere plays a significant role upon the nature of decomposition as well as the type of thermoproducts and their thermal stability. The present study gives also an idea about the nature of interaction of the water of crystallization. The mixed oxide obtained from the thermal decomposition of Ag2Ni(C2O4)2 · 2H20 in air and N2 has been investigated. The XRD and SEM results suggest the formation of a mixed lattice oxide Ag2NiO2.

Thermal behaviour of some aromatic diamine complexes

Abstract The Co(II) and Ni(II) complexes of some aromatic diamines were prepared and characterised by different analytical and spectral methods. The thermal behaviour of the investigated complexes was also studied. The thermal stabilities of the complexes were discussed in terms of chelate ring size and localised electron model.

Thermochromism in Ni(ii) complexes with schiff base derivatives of 4-aminoantipyrine

Abstract Ni(II) complexes of 2-hydroxy-1-naphthylidene-4-aminoantipyrine (I) and salicylidene-4-aminoantipyrine (II) display a change of colour upon heating. The change in II is reversible in the presence of moisture. The thermochromism in crystalline I and II has been studied using differential thermal analysis (DTA), electronic and IR spectroscopy. X-ray powder diffraction and electrical conductivity. Thermochromism in these complexes has been attributed to dehydration.