Ap. Robertson et Jo. Leckie, Acid/base, copper binding, and Cu2+/H+ exchange properties of a soil humicacid, an experimental and modeling study, ENV SCI TEC, 33(5), 1999, pp. 786-795
Citations number
42
Categorie Soggetti
Environment/Ecology,"Environmental Engineering & Energy
Acid/base, copper binding and proton exchange properties of a soil humic ac
id were studied over a range of pHs and ionic strengths. Results indicate t
hat multiple classes of copper binding sites exist. A number of model formu
lations were used to simulate the data; none were able to reasonably match
all aspects of the observed behavior. Model results and analyses suggest th
at successful replication of humic behavior over a wide range of conditions
requires a model formulation which incorporates electrostatic effects for
a variable geometry entity, multiple site classes, and probably both uni an
d multi dentate complexation. Additionally site heterogeneity estimates fro
m acid/base titration data are not likely to reasonably assess the presence
of low concentration, high (metal) affinity sites that can be relevant in
the study of trace metal complexation.