2 results

Model of inner-sphere adsorption of oxyanions in goethite – Why is phosphate adsorption more significant than that of sulfate?

Carla Gomes de Albuquerque ORCID logo , Fabiana Gavelaki ORCID logo , Vander Freitas Melo ORCID logo , Antônio Carlos Vargas Motta ORCID logo , Aldo José Gorgatti Zarbin ORCID logo , Caroline Mariano Ferreira ORCID logo

07/Apr/2022

ABSTRACT Phosphorus availability in soils is low due to its strong retention by inner-sphere complexation on minerals in the clay fraction with pH-dependent charges, such as goethite. On the other hand, sulfur has greater availability because it is retained mainly by electrostatic attraction. We evaluated the intensities of the inner-sphere complexation of orthophosphate and sulfate (H2PO4-/HPO42- and SO42- – generically treated as PO4 and SO4) under different experimental conditions (pH, goethite purity, and contact times) on synthetic goethite samples to […]

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SEQUENTIAL EXTRACTION OF PHOSPHORUS BY MEHLICH-1 AND ION EXCHANGE RESIN FROM B HORIZONS OF FERRIC AND PERFERRIC LATOSOLS (OXISOLS)

Danilo de Lima Camêlo, João Carlos Ker, Roberto Ferreira Novais, Marcelo Metri Corrêa, Vinício Coelho de Lima

01/Jul/2015

In general, Latosols have low levels of available P, however, the influence of the parent material seems to be decisive in defining the pool and predominant form of P in these soils. This study evaluated P availability by extraction with Mehlich-1 (M-1) and Ion Exchange Resin (IER), from samples of B horizons of Ferric and Perferric Latosols developed from different parent materials. To this end, in addition to the physical and chemical characterization of soils, 10 sequential extractions were performed […]