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  • Author or Editor: J. Dávila Rangel x
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Summary  

The sorption of cobalt from aqueous solutions was studied for two Mexican clinoptilolite rich tuffs zeolitic rocks and kaolinite clay. The effects of pH and contact time on the sorption were examined. Cobalt was determined by neutron activation analysis of the exchanged aluminosilicates. The sorption of cobalt by the aluminosilicates was similar in the pH range from 4 to 7. Kinetic studies showed a rapid sorption in the first 5 hours and equilibrium in about 24 hours. Sorption kinetics was best described by the second-order Ritchie modified model. The experimental results obtained at different concentrations and room temperature for both zeolites were fitted to Freundlich, Langmuir and Freundlich-Langmuir isotherms. The sorption pattern was found to follow the Freundlich model.

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Summary  

The sorption of cadmium from aqueous solutions was evaluated in three Mexican aluminosilicates (two zeolites and one clay). The effects of pH and contact time on the sorption process were examined. Cadmium was analyzed by neutron activation analysis in the exchanged aluminosilicates. The sorption of cadmium by aluminosilicates was the same in the pH range from 4 to 8, considering the standard deviation. Kinetic studies were carried out and showed a rapid sorption of cadmium in the first 5 hours but the equilibrium was reached in about 20 hours. The sorption kinetics of cadmium ions was best described by the second-order Ritchie modified model. The experimental results obtained in different concentrations and at room temperature for both zeolites were fitted with classical isotherms of Freundlich, Langmuir and Freundlich-Langmuir models. The sorption pattern followed the Langmuir-Freundlich model.

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Abstract  

The conditions to measure the gross alpha and gross beta radioactivity in water samples from Zacatecas and Guadalupe cities in the State of Zacatecas, Mexico were established. The gross alpha and beta radioactivity of water samples were measured using a liquid scintillation detector. The results show that the gross beta radioactivity in all cases is lower than the maximum contaminant level and the gross alpha radioactivity is higher in the samples collected from Guadalupe City and in the samples collected from the Southwest of Zacatecas City.

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