resumo
Cadmium(II) is a toxic hazardous cation, whose presence in the environment causes great concern because of its bioaccumulation in organisms and bioamplification along food chain. Hence, the removal of cadmium compounds from industrial waters and wastewaters is particularly essential, which requires intensive experimental and modelling studies to deal with the problem. In this work, the ion exchange of Cd2+ ions from aqueous solution using microporous titanosilicates (ETS-4 and ETS-10) has been modelled using adapted Maxwell-Stefan equations for the ions transport inside the sorbent particles. The fundamentals of the Maxwell-Stefan equations along with correlations for the convective mass transfer coefficients have been used with advantage to reduce the number of model parameters. In the whole, the model was able to represent successfully the kinetic behaviour of 11 independent and very distinct curves of both studied systems (Cd2+/Na+/ETS-4 and Cd2+/Na+/ETS-10). The predictive capability of the model has been also shown, since several uptake curves were accurately predicted with parameters fitted previously to different sets of experimental data.
palavras-chave
LENGTH-COLUMN METHOD; EARTH METAL-IONS; MASS-TRANSFER; DIFFUSION-COEFFICIENTS; MICROPOROUS MATERIALS; ELECTROLYSIS PROCESS; NUMERICAL-SOLUTION; CATION-EXCHANGER; AQUEOUS-SOLUTION; HEAVY-METALS
categoria
Environmental Sciences & Ecology
autores
Lito, PF; Aniceto, JPS; Silva, CM
nossos autores
Carlos Manuel Silva
Professor associado
José P. S. Aniceto
Investigador Júnior
Patrícia Ferreira Lito
Bolseiro de pós-Doutoramentoagradecimentos
Patricia F. Lito wishes to thank Fundacao para a Ciencia e Tecnologia (Portugal) for the Grant (SFRH/BPD/63214/2009) provided for this study.