Portal de Periódicos da CAPES

Artigo Acesso aberto Produção Nacional Revisado por pares

BIBTEX RIS

Quantification of permanent and variable charges in reference soils of the State of Pernambuco, Brazil

2014; Sociedade Brasileira de Ciência do Solo; Volume: 38; Issue: 4 Linguagem: Inglês

10.1590/s0100-06832014000400012

1806-9657

Jaílson Cavalcante Cunha, Hugo Alberto Ruíz, Maria Betânia Galvão dos Santos Freire, Víctor Hugo Álvarez V., Raphael Bragança Alves Fernandes,

Landfill Environmental Impact Studies

The electrical charges in soil particles are divided into structural or permanent charges and variable charges. Permanent charges develop on the soil particle surface by isomorphic substitution. Variable charges arise from dissociation and association of protons (H+), protonation or deprotonation, and specific adsorption of cations and anions. The aim of this study was to quantify the permanent charges and variable charges of Reference Soils of the State of Pernambuco, Brazil. To do so, 24 subsurface profiles from different regions (nine in the Zona da Mata, eight in the Agreste, and seven in the Sertão) were sampled, representing approximately 80 % of the total area of the state. Measurements were performed using cesium chloride solution. Determination was made of the permanent charges and the charges in regard to the hydroxyl functional groups through selective ion exchange of Cs+ by Li+ and Cs+ by NH4+, respectively. All the soils analyzed exhibited variable cation exchange capacity, with proportions from 0.16 to 0.60 and an average of 0.40 when related to total cation exchange capacity.