New article in Photochemistry and Photobiology

[Katarzyna Przybyla-Kelly <kprzybyla-kelly@usgs.gov>]

FYI


Journal
of Photochemistry and Photobiology A: Chemistry 
Volume
186, Issues 2-3 , 25 February
2007, Pages 212-217 

TiO2 as a photocatalyst for control of the
aquatic invasive alga, Cladophora, under natural and artificial
light

Julie R. Peller^{a, ,} , Richard L. Whitman^c, , Scott Griffith^a, Patricia Harris^a, Cassie Peller^{a, c} and Joanne Scalzitti<sup>b

a</sup>Department of Chemistry, 3400 Broadway, Indiana University Northwest, Gary, IN 46408, United States
^bDepartment of Biology, 3400 Broadway, Indiana University Northwest, Gary, IN 46408, United States
^cLake Michigan Ecological Research Station, U.S. Geological Survey, Porter, IN 46304, United States

Received 11 July 2006;  revised 14 August 2006;  accepted 14 August 2006.  Available online 23 August 2006.

Abstract

Cladophora, a nuisance and invasive, filamentous algae (Chlorophyta), massively accumulates along the shores of the lower Great Lakes each summer causing great economic damage and compromising recreational opportunity and perhaps public health. In vitro experiments showed that Cladophora samples were physically and biologically degraded when subjected to TiO₂-mediated photocatalysis. For the most successful photocatalytic process, TiO₂ was immobilized on a glass surface and used in combination with either sunlight or artificial UV light. The loss of vital algal pigments was monitored using UV–vis spectrophotometry, and cell structural changes were determined by microscopic observation. Cladophora, in the presence of TiO₂-covered glass beads, experienced a loss of chloroplast pigments after 2 h of UV lamp light irradiation. In a separate experiment, sunlight exposure over 4 days (24 h) resulted in the complete oxidative degradation of the green chloroplast pigments, verified by the UV spectra of the algal extracts. These results suggest that TiO₂, mobilized on sunlit silicates may be useful in controlling growth and survival of this alga in the Great Lakes, thus mitigating many of the economic, aesthetic ecological impacts of this invasive alga.

Keywords: Photocatalysis; Phycotoxicity; Cladophora; Water quality; TiO₂





Kasia Przybyla-Kelly
USGS, Biological Resource Division
Lake Michigan Ecological Research Station
1100 N Mineral Springs Rd.
Porter, IN 46304
219-926-8336 Ext. 427