Leaching of hydrophobic Cu and Zn from discarded marine antifouling paint residues: evidence for transchelation of metal pyrithiones.
Leaching of Cu and Zn from a composite of discarded antifouling paint residues ([Cu] = 288 mg g(-1); [Zn] = 96 mg g(-1)) into natural sea water has been studied over a period of 75 h. Total Cu and Zn were released according to a pseudo first-order reaction, with rate constants on the order of 0.3 and 2.5 (mg L(-1))(-1) h(-1), respectively, and final concentrations equivalent to the dissolution of about 8 and 2% of respective concentrations in the composite. Time-distributions of hydrophobic metals, determined by solid phase extraction-methanol elution, were more complex. Net release of hydrophobic Cu was greater in the absence of light than under a sequence of light-dark cycles; however, hydrophobic Zn release was not detected under the former conditions but contributed up to 50% of total aqueous Zn when light was present. These observations are interpreted in terms of the relative thermodynamic and photolytic stabilities of biocidal pyrithione complexes.
Holmes
Luke
L
School of Earth, Ocean and Environmental Sciences, University of Plymouth, Drake Circus, Plymouth PL4 8AA, UK.
Turner
Andrew
A
D002614:Chelating Agents / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D004202:Disinfectants / Q000737:chemistry*; D057927:Hydrophobic and Hydrophilic Interactions; D010150:Paint / Q000032:analysis*; D011725:Pyridines / Q000737:chemistry*; D012623:Seawater / Q000032:analysis; D013501:Surface-Active Agents; D013871:Thiones / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D015032:Zinc / Q000737:chemistry*
D002614:Chelating Agents; D004202:Disinfectants; D011725:Pyridines; D013501:Surface-Active Agents; D013871:Thiones; D014874:Water Pollutants, Chemical; C008704:pyrithione; D003300:Copper; D015032:Zinc