RETRACTED: Ultrasonic irradiation enhanced degradation of azo dye on MnO2

This article has been retracted at the request of the Editor-in-Chief. Please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). : Dr. Jiantuan Ge has published two articles: Appl. Catal. B: Environ., 47 (2004) 133–140 and J. Hazard. Mater., 100 (2003) 197–207 without informing his co-author Jiuhui Qu of the submission to Applied Catalysis B: Environmental. Many sections of text between the two articles are similar or identical. Moreover, the Journal of Hazardous Materials article, which was accepted 19 March 2003, was not cited in the Applied Catalysis B: Environmental article, which was accepted 18 August 2003.