Kinetics of Copper Complexation with Dissolved Organic Matter Using Stopped-Flow Fluorescence Technique
Journal
Toxicological and Environmental Chemistry
Journal Volume
43
Journal Issue
1-2
Pages
1-12
Date Issued
1994
Date
1994
Author(s)
Abstract
This study provided direct observations on reaction kinetics of Cu and dissolved organic matter (DOM). Stopped-flow method and fluorescence technique were used to measure Cu(II)-DOM complexation over time. Suwannee River reference fulvic acid and water soluble soil organic matter were used as model DOM. Experimental conditions of pH 6, 5 × 10–5M Cu(II), and 5 mg C/L of DOM were used and the results were to simulate the relevant natural conditions. Both organic ligands reacted fairly rapidly with Cu(II). Reaction half-life of DOM was in the millisecond range. Two types of metal binding sites of organic ligands were identified. Fulvic acid yield forward rate constants: 1 × 106M-1s-1and 5.15 × 103M-1s-1, based on second-order reaction rate model. Water soluble soil organic matter gave forward rate constants: 1.34 × 105M-1s-1and 2.2 × 103M-1s1. From comparison of kinetic natures, the fast-reacting ligands were comparable to nitrilotriacetic acid (NTA) and slow-reacting ligands were more like salcylic acid. © 1994, Taylor & Francis Group, LLC. All rights reserved.
Subjects
Cu(II) complexation; dissolved organic matter; kinetics; stopped-flow technique
Other Subjects
Copper complexation; Dissolved organic matter; Stopped flow fluorescence technique; Complexation; Copper; Fluorescence; Heavy metals; Measurements; Monitoring; Reaction kinetics; Removal; Water treatment
Type
journal article