Metal adsorption in soils has been studied in the scope of environmental geotechnics mainly to predict migration of contaminant plumes, to study feasibility of remediation techniques, and to design waste disposal sites. The consideration of adsorption as an immediate and reversible phenomenon is generally accepted in those applications; however, the study of adsorption kinetics in tropical soils may improve back-calculation of field data and interpretation of experimental results. This study presents theoretical aspects of adsorption kinetics, including factors that affect adsorption kinetics, models to determine mechanisms that control adsorption kinetics and adsorption kinetics models. Adsorption and adsorption kinetics of cadmium and lead in a Brazilian lateritic red clay were investigated by means of Batch adsorption tests on. Initial solutions concentrations varied from 2 mg/L to 2000 mg/L. Contact times varied from 5 minutes to 6 months. Chemical extraction and digestion tests were also performed. Models were then applied to experimental data to determine the mechanisms that control adsorption kinetics and adsorption kinetics models were also fitted to experimental data. The results show that adsorption can be represented by two different behaviors: a short time behavior, until circa 8 hours, and a long time behavior, for longer times. For cadmium, the importance of non specific adsorption increases as the contaminant concentration in the solid phase increases, while this relation is not clear for lead. The investigated adsorption kinetics models can only represent the short time behavior, and fitting of these models, even for short-time adsorption, depends considerably on the utilized mathematical method. Finally, adsorption kinetics can be well represented by a power function with negative exponent.
Ao meu pai (Álvaro), minha mãe (Roseli), e meus irmãos (Catarina, Júlia, Glória e Matheus), pelo amor e incentivo. Aos meus sobrinhosOtávio e Daniel. À minha tia/amiga Meloca e sua família, pelo enorme carinho e apoio. Às minhas avós Alzira e Brígida. Ao Prof. Dr. Madson Cortes de Almeida, pela orientação, atenção e disponibilidade no desenvolvimento deste trabalho. Aos Professores Luiz Carlos Pereira da Silva e Carlos Alberto de Castro Jr. pela orientação no programa de estágio docência (PED) e ensinamentos não só acadêmicos mas também pessoais. A todos os amigos do DSEE, em especial Fabiano, Victor, Paulo e Rafael, por terem contribuído direta e indiretamente com o desenvolvimento desse trabalho. Às amizades feitas nesse período de mestrado, em especial Yuri, Oriana, Vanessa, Márcio, Gustavo e Ricardo.
Tabla 2: Niveles de ruido propuestos para lograr la homologación bajo normativa 9297/CEE (Medidas Objetivo a 7.5 m de distancia) 1.-Comunicado de prensa OMS, nuevas pruebas de la OMS sobre los efectos para la salud relacionados con ruido del tráfico en Europa, Bonn y Copenhague (30 de marzo 2011):www.euro.who.int/en/what-we-do/health-topics/environmental-health/noise 2.-CE Delft (2007): reducción del ruido del tráfico en Europa: efectos de salud, los costos sociales y opciones técnicas y políticas para reducir el ruido por carretera www.transportenvironment.org/Publications/prep_hand_out/lid:495 3.-Fuente: programa "QUIET please" de la Unión Europea: Better health through strong EU regulation of road and rail traffic noise OPTIMIZACION DEL CONFORT ACUSTICO-TERMICO EN VEHICULOS CONVENCIONALES (MCIA) Y ELECTRICOS Una vez más, no es posible adoptar un único conjunto de objetivos de ruido aplicables a todos los motores posibles, pero se ofrece un conjunto indicativo en la tabla 1.4. Esta tabla se refiere a un motor diesel particular usado en camionetas europeas y vehículos deportivos utilitarios. Componente Nivel Sonoro Carter 102 Bloque 104 Culata 93 Escape 102 Aspitación 97 Bomba inyección 96 Total 108 Tabla 3: Objetivos típicos en potencia sonora en dB para un motor diesel de 4 litros atmosférico inyección directa (usado típicamente en camionetas y deportivos) 2.1.2.2.2. Objetivos del ruido exterior radiados por la aspiración: Comúnmente se establecen como niveles máximos de presión acústica, registrados a una distancia de 100 mm desde la entrada de aire a un ángulo de incidencia de 90°.
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