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Journal of Nanomaterials
Volume 2012, Article ID 512956, 6 pages
Research Article

Toxicity of Aqueous Fullerene nC60 to Activated Sludge: Nitrification Inhibition and Microtox Test

1Research Center for Environmental Quality Management, Kyoto University, 1-2 Yumihama, Otsu 520-0811, Japan
2Testing and Analysis Division, Shimadzu Techno Research Inc., 1 Nishinokyo-Shimoaicho, Nakagyo-ku, Kyoto 604-8436, Japan

Received 3 April 2012; Accepted 11 June 2012

Academic Editor: Xiaoming Li

Copyright © 2012 Yongkui Yang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The increasing production and use of fullerene nanomaterials raised their exposure potential to the activated sludge during biological wastewater treatment process. In this study, the toxicity of aqueous nanoscaled C60 (nC60) to activated sludge was investigated using nitrification inhibition and Microtox test. The test solutions of nC60 were prepared using two methods: long stirring (Stir/nC60) and toluene exchange (Tol/nC60). The nC60 aggregation in test medium was also evaluated for toxicity assessment. The results showed that the nC60 aggregation behaved differently in two test mediums during the incubation periods. The nC60 toxicity was greatly influenced by the preparation method. Stir/nC60 presented no significant toxicity to both the nitrification sludge and bioluminescent bacteria at the maximum concentration studied. In contrast, the EC20 of Tol/nC60 was obtained to be 4.89 mg/L (3 h) for the nitrification inhibition and 3.44 mg/L (30 min) for Microtox test, respectively.