Dissolved humic material from three locations on the Ogeechee River Estuary near Savannah, GA, was ultrafiltered into three size fractions and used for kinetic experiments with Cu(II). A Cu(II)-humic mixture was reacted with a colorimetric reagent for Cu(II) and absorbance observed from 50 msec to at least 1835 sec corresponding to rate constants from 0.001-40 sec-1. The apparent dissociation rate constants were distributed over a wide range, with most bound Cu(II) having k > 1 sec-1 (t 1 2 < 0.7 sec). Nearly all the variation seen in the kinetic distribution was among size fractions; as size fraction decreased, the distribution of bound Cu(II) shifted to larger rate constants. Location of sampling stations on the estuary had little effect on results.
ASJC Scopus subject areas
- Geochemistry and Petrology