Nickel sorption mechanisms in a pyrophyllite-montmorillonite mixture

Journal Article · Sat May 15 04:00:00 EDT 1999 · Journal of Colloid and Interface Science

DOI:https://doi.org/10.1006/jcis.1999.6161· OSTI ID:352699

Elzinga, E J; Sparks, D L ^[1]

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1. Univ. of Delaware, Newark, DE (United States). Dept. of Plant and Soil Sciences

Nickel sorption on pyrophyllite, montmorillonite and a 1:1 pyrophyllite-montmorillonite mixture was studied at pH 7.5 and a reaction time of 40 min. The main modes of Ni uptake under these reaction conditions are adsorption on montmorillonite and surface precipitation on pyrophyllite. For the clay mixture, where adsorption on the montmorillonite component and surface precipitation on the pyrophyllite component compete for Ni uptake, X-ray absorption fine structure spectroscopy (XAFS) was used to estimate the distribution of Ni over the mixture components. This was done by comparison to pyrophyllite-montmorillonite mixtures with known Ni distributions over the mixture components. Nickel uptake on singly reacted pyrophyllite was slightly higher than on singly reacted montmorillonite. This was consistent with the XAFS results for the clay mixture, which suggested that the pyrophyllite component sorbed slightly more Ni than the Montmorillonite component. The findings suggested that both adsorption and surface precipitation were important mechanisms in the overall Ni uptake in the clay mixture, and that neither sorption mechanism truly out-competed the other in the reaction time of 40 min employed. Therefore, both mechanisms should be considered when modeling Ni sorption in similar systems.

• OSTI ID: 352699
• Journal Information: Journal of Colloid and Interface Science, Journal Name: Journal of Colloid and Interface Science Journal Issue: 2 Vol. 213; ISSN 0021-9797; ISSN JCISA5
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ADSORPTION
ENVIRONMENTAL TRANSPORT
KINETICS
MONTMORILLONITE
NICKEL
PRECIPITATION
PYROPHYLLITE
SORPTIVE PROPERTIES