title: Photocatalytic atrazine degradation by synthetic minerals, atmospheric aerosols, and soil particles.
abstract: In this work, the photocatalytic atrazine degradation by seven synthetic minerals and five environmental particle samples was examined to investigate a possible contribution of photocatalysis to the abiotic degradation of atrazine in the environment. Particle suspensions containing 500 ng/L atrazine were irradiated with a sun simulator, and the atrazine degradation was monitored by enzyme-linked immunosorbent assay (ELISA). Atrazine detection by ELISA proved to be an useful analytical tool because of low cross-reactivity of atrazine metabolites and high sensitivity with detection limits in the lower nanograms per liter range. The atrazine degradation followed first-order kinetics, and the obtained rate coefficients were compared with the rate of direct photolysis. Known photocatalysts, such as TiO2 and ZnO, showed the expected fast photocatalytic degradation (k = 27-327 x 10(-3) min(-1)) of atrazine. The degradation rates detected upon irradiation of titanium-, zinc-, or iron-containing minerals were orders of magnitudes lower (k = 0.15-0.70 x 10(-3) min(-1)) but still significantly faster than direct photolysis without particles (k = 0.10 x 10(-3) min(-1)). With environmental particle samples (soot, fly ash, sand, road dust, and volcanic ash), however, no significant photocatalytic activity was observed (k = 0.07-0.16 x 10(-3) min(-1)). The atrazine degradation rates were in the range of direct photolysis. Thus photocatalysis by aerosol or soil particles appears not to enhance abiotic atrazine degradation in the environment.
authors.affiliation: Institute of Hydrochemistry, Technical University of Munich, Marchioninistrasse 17, D-81377 Munich, Germany.
authors.forename: Marion
authors.initials: M
authors.lastname: Lackhoff
authors.forename: Reinhard
authors.initials: R
authors.lastname: Niessner
mesh_terms: D000336:Aerosols; D000393:Air Pollutants / Q000032:analysis* / Q000494:pharmacology; D000465:Algorithms; D001280:Atrazine / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects / Q000528:radiation effects; D004797:Enzyme-Linked Immunosorbent Assay; D008027:Light; D008903:Minerals / Q000032:analysis* / Q000494:pharmacology; D010316:Particle Size; D012987:Soil / Q000032:analysis*; D012988:Soil Microbiology
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D008903:Minerals; D012987:Soil; D001280:Atrazine