Data/hora: 13/06/2024 07:24:27

Provedor de dados: 	63	
País: 	Brazil	
Título: 	Copper desorption in a soil with variable charge	
Autores: 	Casagrande,José Carlos; Jordão,Camila Beig; Alleoni,Luís Reynaldo Ferracciú; Camargo,Otávio Antônio de.	
Data: 	2004-04-01	
Ano: 	2004	
Palavras-chave: 	Copper; Desorption; Ionic strength; PH.	
Resumo: 	Adsorption processes of heavy metals in soils have been more extensively studied than desorption, in spite of this latter process being related to nutrient bioavailability in the soil solution. Copper desorption from surface (0-0.2 m) and subsurface (1.0 - 1.2 m) samples of an Anionic Acrudox was studied at two pH values (4.5 and 7.5). Soil samples were incubated with Cu rates varying from 0 to 400 mg kg-1, during 4 and 12 weeks, in the presence of CaCl2 as support electrolyte at concentrations of 0.01 and 0.001 mol L-1. Complete soil adsorption of added Cu was observed at pH 7.5 in all incubation periods, indicating that a 24h-shaking period was enough to reach equilibrium and maximum adsorption. Copper adsorption varied with the incubation period and was much lower at pH 4.5 than at pH 7.5, after the 24 hour-incubation period. After 4 and 12 weeks, Cu adsorption values were higher and similar for all soil samples, irrespective of pH or depth of sampling. The effect of the incubation period on soil Cu adsorption surpassed the pH effect for all Cu rates. The hysteresis was expressive, suggesting that Cu enhances high-energy bonds with the soil colloids. Calcium chloride was not efficient in promoting native soil Cu desorption in the studied concentrations.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162004000200012	
Editor: 	São Paulo - Escola Superior de Agricultura "Luiz de Queiroz"	
Relação: 	10.1590/S0103-90162004000200012	
Formato: 	text/html	
Fonte: 	Scientia Agricola  v.61 n.2 2004	
Fonte: 	info:eu-repo/semantics/openAccess