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Retention of Ni, Zn and Cd by Si‐associated goethite
Author(s) -
Gerth Joachim,
Brümmer Gerhard W.,
Tiller Kevin G.
Publication year - 1993
Publication title -
zeitschrift für pflanzenernährung und bodenkunde
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.644
H-Index - 87
eISSN - 1522-2624
pISSN - 0044-3263
DOI - 10.1002/jpln.19931560205
Subject(s) - goethite , dissolution , sorption , chemistry , metal , inorganic chemistry , amorphous solid , oxide , nuclear chemistry , adsorption , crystallography , organic chemistry
Abstract Synthetic goethite used to study the effects of reaction time and temperature on the pH‐dependent sorption of Ni, Zn and Cd was associated with amorphous silica. Ni interacted with dissolved Si and formed a Ni/Si precipitate on the goethite surface. Individual metals added at a concentration of 0.5 μmol g −1 and sorbed during a reaction period of 504 hours (21 days) at 35°C were extracted by 0.7 M HNO 3 for 14 days. At the end of this period 11,28 and 40 percent of Ni, Cd and Zn, respectively, were not extracted whereas 20 percent of the total Fe content of the goethite and 39 percent of the associated Si were dissolved. During the sorption process metals became immobilized in the goethite particles. This effect can be related to a diffusion of metal ions into micropores. A total mobilization of sorbed metals can only be achieved by a complete dissolution of the goethite. The strong fixation of Ni, Zn and Cd by goethite suggests that additions of this Fe oxide could be used to ameliorate highly contaminated sludges or soils.