[en] Complete text of publication follows. The degradation kinetics due to irradiation of aqueous solutions of two acid dyes, namely Sandolane Milling N-Bl and Telon Fast Red and a basic dye (Sandocryl Blue B-3G) has been investigated. The factors affecting the radiolysis of the dyes such as dye concentration, irradiation dose, dose rate and pH of the solutions were studied. The effect of irradiation dose on various dye concentrations showed the complete destruction of the dyes at a dose of 4 kGy for low dye concentrations (20-50 mg/l), while at higher concentrations (100 mg/l) a dose of 20 kGy did not achieve the same effect. A combined treatment of the dye solutions by gamma irradiation and conventional methods showed that the saturation of these solutions did not enhance the degradation of the dyes. However, the addition of oxygen, hydrogen peroxide and sodium hypochlorite to the dye solutions coupled with γ-irradiation resulted in a remarkable enhancement in the degradation process and complete degradation of these pollutants was achieved using much lower doses of gamma radiation

[en] Carbon membrane made of a mixture of activated carbon and poly vinyl alcohol (PVA)/ N-vinyl pyrrolidone (NVP) was made by single freezing and thawing of the mixture followed by gamma irradiation. The prepared membrane was characterized by SEM, and gel content. The membrane was applied for adsorption of some heavy metal ions such as Co and Ni and dichromate anion from their aqueous solutions. From the results it was found that the prepared membrane possesses greater efficiency towards removal of heavy metal ions than activated carbon. The results have been discussed. (author)

[en] A try was made in the present work to explain the degradation kinetics due to irradiation of aqueous solutions of some materials used in the textile industry such as leomin KW.ET and leomin Ni.ET) (softeners), cassurit HMl and solusoft WAL-ET (finishing agents) and Hostalux-Cs. (Optical Brightner). A combined treatment of gamma irradiation and conventional methods was applied to some concentrated waste solutions in manageable volumes. The combined treatment was more effective than either alone. factors affecting the radiolysis of the pollutants such as concentration, irradiation does, dose rate and PH of the solutions were studied. For the finishing, softening and optical brightener agents (F1, S1 and B1), complete degradation was achieved for low concentrations of these materials, while for higher concentrations this goal was not achieved. This may be due to the difference in their physico-chemical characteristics. Also, Using a low dose rate (0.165 Gy/Sec) resulted in more degradation of the pollutants than using higher dose rates (0.65 Gy/Sec). The effect of different additives such as nitrogen and oxygen on the degradation process of these pollutants was investigated. Nitrogen did not affect the percent of degradation, while oxygen enhanced the degradation process remarkably. It may be concluded that the radiation degradation of the toxic pollutants and their removal from wastewater down to concentrations not exceeding the maximum permissible concentration (MPC), according to international standards, proved to be better than the conventional methods of purification alone and perhaps more economical as well

[en] Aqueous solutions of two reactive dyes, drimarene navy KGRL and drimarene scarlet K-2 G were easily degraded by gamma radiation. The effect of dye concentration, irradiation dose, dose rate and Ph of the dye solutions were studied. More degradation of these dyes was observed in the acidic medium than the neutral and alkaline media. Synergistic treatment of the dye solutions by irradiation and conventional methods showed that the saturation of the dye solutions with nitrogen did not enhance the radiation degradation of the dyes. On the contrary, addition of oxygen resulted in a remarkable enhancement of the radiation degradation of the dye solutions. The addition of sodium hypochlorite (5%) and the oxidation by hydrogen peroxide of concentration 5x10^-3 mol. dm^-3 resulted in more radiation degradation. It may be concluded that radiation degradation of the toxic dye pollutants and their removal from wastewater down to concentrations not exceeding the maximum permissible concentration (MPC) according to international standards, proved to be better than the conventional methods of purification alone

[en] Modified bentonites as cation exchangers were prepared by treating raw bentonite with 3N NaOH at 95⁰C followed by in-situ polymerization using gamma irradiation as well as hydrogen peroxide initiation of acrylic acid or acrylamide in the matrix.Water swelling and acid capacity were determined and cation exchange capacity for Cu²⁺, Ni²⁺ and Co²⁺ was evaluated. It has been found that catiexchange capacity of treated bentonite was increased as result of formed polyacrylic acid and polyacrylamide in the matrix. In case of acrylic acid, the maximum cation exchange capacities of 3.5, 3.1 and 2.5 mg equivalent/g were determined for Cu²⁺, Ni²⁺ and Co²⁺, respectively, and for acrylamide, the corresponding capacities were 2.9, 2.8 and 2.6 mg equivalent/g, respectively. Water swelling was found to be associated with holding large amounts of water, for instance, 49 g of water was sorbed per one gram of the sodium salt form of polyacrylic acid in bentonite matrix, in other words the degree of swelling in water achieved 4500%.

[en] Polyvinyl alcohol /Acrylic acid based hydrogels can be synthesized by Gamma radiation technique using ⁶⁰Co irradiation cell at irradiation dose rate 1.8 Gray/second. The optimum conditions of hydrogel preparation takes place at different factors such as composition ratios of PVA/AAc, different comonomer concentration and different irradiation doses resulting in hydrogel with maximum gel percent as it obtained 98%. The structures of hydrogels were characterized by FTIR analysis. The results can be confirmed the expected structures as well as free radical copolymerization. According to the swelling studies, hydrogels with high content of AAc gave relatively high swelling percent. The hydrogel showed a super adsorbent with swelling capacity 10320 %. Water diffusion into such prepared hydrogel showed a non-Fickian type where a Fickian number was 0.77. This hydrogel was used for the adsorption of amoxicillin drug from their aqueous solutions. The factors affected on the uptake conditions such as ph, time and initial feed concentration on the amoxicillin adsorption capacity of hydrogel was studied depending on Freundlish model of adsorption isotherm.. It was observed that the interaction between drug and ionic comonomers was enhanced in alkaline medium and high initial feed concentration of the drug. The ability of the hydrogel and the affinity of the drug to be adsorbed can be cleared by determining the empirical constants n and k respectively from the logarithmic form of Freundlish equation. The recovery of drug was also investigated in different ph values to study the suitable condition of drug release as drug delivery system.

[en] Copper and nickel oxide samples supported on MgO were prepared by wet impregnation method. The obtained solids were heated at 350 deg C and 450 deg C. The extent of copper and nickel oxides was fixed at 16.7 mol%. The effect of g-irradiation (0.2-1.6 MGy) on the surface and catalytic properties of the solids were investigated. The techniques employed were XRD, nitrogen adsorption at -196 deg C and H₂O₂ decomposition. The results revealed that the g-irradiation up to 0.8 MGy of CuO/MgO-450 deg C effected a measurable decrease in the crystallite size of CuO phase with subsequent increase in its degree of ordering. Irradiation at a dose of 1.6 MGy brought about a complete conversion of MgO into Mg(OH)₂ during its cooling from 450 deg C to room temperature via interacting with atmospheric water vapor. The S_BET and total pore volume of CuO/MgO precalcined at 350 deg C and 450 deg C increased progressively as a function of γ-ray dose reached a maximum limit at 0.8 MGy. Gamma-irradiation of NiO/MgO-450 deg C solids up to 0.8 MGy increased the degree of ordering of MgO and NiO phases without changing their crystallite size. The exposure of these solids to 1.6 MGy led to an effective transformation of some of NiO (not dissolved in MgO lattice) into Ni(OH)₂ via interacting with atmospheric water vapor during cooling from 450 deg C to room temperature. Gamma-irradiation led to a measurable increase in the S_BET and V_p of NiO/MgO system. Gamma-irradiation of the two investigated systems resulted in both increase and decrease in their catalytic activities in H₂O₂ decomposition depending mainly on the irradiation dose and calcination temperature. This treatment, however, did not modify the mechanism of the catalytic reaction, but changed the catalytic active sites without changing their energetic nature. (author)

[en] Super absorbent hydrogels based on the natural polymer chitosan and acrylic acid (CS/AAc) was prepared using 60 Co gamma radiation as a source of initiation and crosslinking, The factors, which affect the preparation of CS/AAc hydrogels such as irradiation dose, CS/AAc ratios, and acrylic acid monomer concentrations, to get the best optimum conditions, were investigated, The kinetic studies of the swelling of CS/AAc hydrogel showed that it follows a Fickian type of water diffusion, The Fickian constant value 'n' was more than 0.5 with a high swelling capacity of 300 gig as super absorbent hydrogel. In addition, the suitability of CS/AAc hydrogel as carrier material for the drug Chlortetracycline-H CI has been investigated by adsorption isotherm studies. The performance of drug release from hydrogel systems, influenced by acrylic acid ratio and the effect of ph of the medium was studied

[en] Super absorbent hydrogels based on the natural polymer chitosan and acrylic acid (CS/AAc) was prepared using 60 Co gamma radiation as a source of initiation and crosslinking, The factors, which affect the preparation of CS/AAc hydrogels such as irradiation dose, CS/AAc ratios, and acrylic acid monomer concentrations, to get the best optimum conditions, were investigated, The kinetic studies of the swelling of CS/AAc hydrogel showed that it follows a Fickian type of water diffusion, The Fickian constant value 'n' was more than 0.5 with a high swelling capacity of 300 gig as super absorbent hydrogel. In addition, the suitability of CS/AAc hydrogel as carrier material for the drug Chlortetracycline-HCl has been investigated by adsorption isotherm studies. The performance of drug release from hydrogel systems, influenced by acrylic acid ratio and the effect of Ph of the medium was studied