[en] In an attempt to develop an environmentally friendly bifunctional graft copolymer for wastewater treatment, a grafted starch with amphoteric character was prepared by grafting the mixed monomer system of acrylic acid (AAc) and N-vinylpyrrolidone (NVP) onto naturally occurring maize starch using g-irradiation, followed by amination of the produced graft copolymer with diethylene triamine (DETA) and characterized by FTIR and SEM. The prepared bifunctional graft copolymer was applied for removal of cadmium and dichromate from aqueous solution, adsorption results showed that the adsorption tendency of bifunctional copolymer towards C d is higher at ph 6 than at ph 3 and obeys freundlich isotherm, whereas the adsorption behaviour towards dichromate is higher at ph 3 compared with ph 7 and 9 and obey both Freundlich and Langmuir isotherm

[en] Acrylic acid (AAc) grafted cotton fabric was prepared by radiation- induced graft polymerization. Grafting conditions were optimized and the sample with grafting percentage 160% were used for further experiments. (AAc) grafted chains were quaternized by introduction of a tertiary amine function onto the sample by the estrification of the carboxylic groups, via an acid chloride intermediate, with 4-hydroxy-N-methyl piperidine. The tertiary amine of the piperidine ring was then quarternized with benzyl chloride. The prepared anion exchanger was characterized by FTIR and SEM. Adsorption experiments were conducted with quarternized (AAc) grafted cotton fabric for sulphate removal at concentration (100-500 ppm) at different ph values. Adsorbed sulphate amounts were found to be (60, 32.5 and 22.5 mg/g) at ph 3, 7 and 9, respectively, showing the efficiency of the adsorbent material in the removing sulphate. Also the results showed that the adsorption data fit the Freundlich isotherm model. Kinetic data were fitted using pseudo-first-order, pseudo-second order equations and with the pseudo-second-order equation generated being in best agreement with the experimental data for the adsorption systems

[en] Network wood pulp based on acrylonitrile has been chemically modified through different reactions to obtain group capable of anion exchange. Graft copolymerization of acrylonitrile onto wood pulp was carried out by using gamma-radiation ⁶⁰Co. Factors affecting the grafting process e.g radiation dose and monomer concentration were investigated.The chemical modification of cyano groups were carried out by reaction with ethanol amine producing oxazoline group followed by quaternization of tertiary amine by reaction with benzyl chloride producing quaternary ammonium salt. The grafted and modified wood pulp were characterized by FTIR, SEM and TGA.Qualitative experiments of adsorption were conducted to evaluate the modified wood pulp on fixing sulfate, phosphate,nitrate and dichromate from aqueous solution using batch extractions. Based on the results obtained, it may be concluded that it is possible to modify chemically wood pulp containing cyano groups by different routes for its usage as anion exchanger

[en] Decomposition by ionizing radiations of two pesticides (Lannate and Fenvalerate) present in an aqueous solution has been studied on laboratory-scale experiments. The effect of pH of the solution, the concentration of the pesticide and the irradiation dose on the degradation process was investigated. Gamma-irradiation was carried out in air and in combination with nitrogen, oxygen and ozone. Lannate showed more degradation than Fenvalerate in all conditions investigated. Radiation was not enough to achieve the complete decomposition of the pesticides. Adsorption of the pollutants after irradiation was achieved using granular activated carbon (GAC) and two anion exchangers (Dowex 1-X8 and Lewatit AP 246). (author)

[en] In the present study, a try was made to explain the degradation kinetics due to irradiation of aqueous solutions of some active ingredient pesticides. These pesticides are as follows: one type of triazine herbicide Ametryn and one type of carbamate insecticide (Applaud) and two types of chlorinated organic pesticides, Aldrin and Chlorothalonil. Factors affecting the radiolysis of these pesticides such as the pesticide concentration, irradiation dose, dose rate and pH of the solutions were studied. Ametryn, Applaud, Chlorothalonil and Aldrin insecticides were degraded by gamma radiation and in the case of the chlorinated pesticides hydrochloric acid was detected. The pH effect has proved to vary according to the type of the pesticide and little degradation was observed in alkaline medium, while more degradation of the pesticides in the neutral medium was observed depending on the type of pesticide and on its chemical structure. However, the degradation in the acid medium was even higher. A drop in pH was observed and may be attributed to the degradation of the pesticide molecules to lower molecular weight compounds, such as organic acids. A combined treatment of gamma irradiation and conventional methods was applied and the effect of different additives such as nitrogen and oxygen showed that nitrogen did not enhance the degradation, while an enhancement in the degradation process was observed when oxygen was added. Experiments on the adsorption of these pesticides on certain polymeric materials and on Granular Activated Carbon (GAC), showed that GAC has the highest adsorption capacity. It may be concluded that the radiation degradation followed by adsorption of the toxic pesticide 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. (author)

[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] The treatment of wastewaters containing toxic pesticides poses a serious environmental problem. Many of the pesticides are not readily biodegradable and complete removal in many cases is a relatively expensive process. Ionizing radiations proved to be more effective for the treatment of these wastewaters than ordinary conventional methods. In the present study a try was made to explain the degradation kinetic due to irradiation of aqueous solutions of some active ingredient pesticides.. These pesticides are: two Organophosphorous Pesticides; Dimethoate and Sumithion and one Organo chlorine Pesticide: DDT. A combined treatment of gamma irradiation and conventional methods was applied . Factors affecting the radiolysis of pesticides such as pesticide concentration, irradiation dose, dose rate and ph of the solutions were studied. The effect of different additives such as nitrogen and oxygen showed an enhancement in the degradation process. Experiments on the adsorption of pesticides on some polymeric materials and on Granular Activated Carbon (GAC), showed that GAC has degradation followed by adsorption of the toxic pesticide 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 and more economical as well

[en] The adsorption of cupper, lead, cobalt and nickel from water by granular activated carbon (GAC), a strong cation exchanger (Dowex 50 w-x 8), calcium aluminum silicate and bentonite clay was studied. Batch experiments were carried out to determine the time to maintain equilibrium followed by adsorption isotherm. results obtained by using the different adsorbents were found to match with the freundlich equation. Different factors that affect the absorbability of dissolved metals were studied; among these the chemical form, solution Ph and ionic radii. The results showed that the adsorption treatment by using calcium aluminum silicate and bentonite clay resulted in more removal percent than GAC, and the strong cation exchanger. The removal of heavy metal ions from water using gamma irradiation has been investigated for the cases of Cu²1, Pb²1, Co²1 and Ni²1 ions. These metal ions are reduced by hydrated electrons and hydrogen atoms to lower valence state and eventually precipitate out of solutions

[en] Decomposition of two pesticides as active ingredient (Lannate and Fenvalarate) present in aqueous solution by ionizing radiations has been studied on laboratory-scale experiments. The effect of ph of the solution, the concentration of the pesticide and the irradiation dose on the degradation process was investigated carried out alone and in combination with other additives such as nitrogen, oxygen and ozone. A synergistic effect was detected which enhanced the degradation process remarkably. Lannate showed more degradation than Fenvalarte under conditions investigated. Radiation alone was not enough to achieve the complete decomposition of the pesticides. Adsorption of the un degraded pollutants was achieved using Granular Activated Carbon (GAC) and two anion exchangers (Dowex 1-X 8 and Lewatit AP 246) It may be concluded that irradiation followed by adsorption resulted in the removal of these organic pollutants from wastewater

[en] Radiation induced decomposition of various organic hydrocarbons such as pesticide (Atrazine) and dye (Cresol Red) in water represents a new and very efficient possibility for elimination of the steadily increasing pollution. Experimental results considering the removal of pesticides and dyes alone and in their mixtures were studied. Adsorption of the remaining part of the under graded pollutants will be carried out using granular activated carbon (GAC) and acrylamide (AAm) graft copolymer onto poly vinylalcohol (PVA).Freundlich model will be used to predict the equilibrium uptake of pesticide and dye in binary and single solutions.the preliminary results show that the method of radiation combined with adsorption using GAC was effective than that of a graft copolymer