Rapid kinetics of Cu(II) adsorption/desorption on geothite

Journal Article · Mon Aug 01 04:00:00 EDT 1994 · Environmental Science and Technology; (United States)

DOI:https://doi.org/10.1021/es00057a008· OSTI ID:7173319

Grossl, P R; Sparks, D L ^[1]; Ainsworth, C C ^[2]

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1. Univ. of Delaware, Newark, DE (United States)
2. Pacific Northwest Lab., Richland, WA (United States)

The kinetics of Cu[sup 2+] adsorption/desorption on goethite ([alpha]-FeOOH) was evaluated using the pressure-jump (p-jump) relaxation technique. This technique provides both kinetic and mechanistic information for reactions occurring on millisecond time scales. A double relaxation event was observed for Cu[sup 2+] adsorption/desorption on goethite. The rate of these relaxations ([tau]) decreased with an increase in pH, along the adsorption edge. The mechanism ascribed to the relaxations is the formation of a monodentate innersphere Cu[sup 2+]/goethite surface complex. The calculated intrinsic rate constant for adsorption (k[sub 1][prime]int) was 10[sup 6.81] L mol[sup [minus]1] s[sup [minus]1] and was about 2 orders of magnitude larger than the intrinsic rate constant for desorption (k[sub 1][prime]int = 10[sup 4.88] L mol[sup [minus]1] s[sup [minus]1]). Using results from this study and others, it was established that the rate of adsorption of divalent metal cations on goethite was directly related to the rate of removal of a water molecule from the primary hydration sphere of a particular divalent metal cation. 30 refs., 7 figs., 1 tab.

• DOE Contract Number: AC06-76RL01830
• OSTI ID: 7173319
• Journal Information: Environmental Science and Technology; (United States), Journal Name: Environmental Science and Technology; (United States) Vol. 28:8; ISSN ESTHAG; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201 -- Chemical & Physicochemical Properties
54 ENVIRONMENTAL SCIENCES
540320* -- Environment
Aquatic-- Chemicals Monitoring & Transport-- (1990-)
ADSORPTION
CHARGED PARTICLES
COPPER IONS
DESORPTION
GOETHITE
HYDRATION
IONS
KINETICS
MINERALS
OXIDE MINERALS
PH VALUE
POLLUTION
REACTION KINETICS
RELAXATION
SOLVATION
SORPTION
WATER POLLUTION