The 96 h acute toxic effects of nano-CuO (N-CuO), micro-CuO (M-CuO) and 2+ on Chlorella sp. were investigated in this paper. The results showed that toxicities decreased in an order of Cu2+＞N-CuO＞M-CuO. The 96 h EC50 of Cu2+ on Chlorella sp. was 1.06 mg /L, and of N-CuO it was 74.61 mg /L, while no pronounced toxicity was observed when the concentration of M-CuO was lower than 160 mg/L. Further experiments were carried out in order to study the toxicity mechanism of nano-CuO on Chlorella sp.. The results of Cu2+ release from N-CuO showed less than 0.2 mg/L Cu2+ were released, so the release of Cu2+ was not responsible for the toxicity. Further experiments showed N-CuO inhibited formation of Chlorophyll A. Content of Chlorophyll A in the control group was 4.75 mg/108 cells, while it declined to 2.89 mg/108 cells for 160 mg/L N-CuO after 96 h, which indicated that N-CuO could inhibit photosynthesis of Chlorella sp.. Moreover, N-CuO condensed with algal cells. It affected the activity of SOD and POD, indicating that N-CuO could cause oxidant stress to Chlorella sp.. These may be the toxicity mechanism.
Cite this paper
L. Wang, M. Wang, C. Peng and J. Pan, "Toxic Effects of Nano-CuO, Micro-CuO and Cu2+ on Chlorella sp.," Journal of Environmental Protection, Vol. 4 No. 1, 2013, pp. 86-91. doi: 10.4236/jep.2013.41B016.
 W. Bai, C. Zhang, W. Jiang, “Progress in studies on environmental behaviors and toxicological effects of nanomaterials,” Asian Journal of Ecotoxicology, Vol. 4, No. 2, 2009, pp. 174-182.
 A. Nel, T. Xia, L. Madler, “Toxic potential of materials at the nanolevel,” Science, Vol. 31, No. 1, 2006, pp. 622—627.
 D. Yang, W. Sun, “Structural characters and special properties of nanomaterials,” Materials Review, Vol. 17, No. 10, 2003, pp. 7-10.
 W. F. Grant, Zinoveva Stahevitch A E, K. D. Zura, “In short term tests for chemical carcinogens,” New York San. Springerverlag, 1981, pp. 200 -216. doi:10.1007/978-1-4612-5847-6_18
 J. Ji, Z. Long, D. Lin, “Toxicity of oxide nanoparticles to the green algae Chlorella sp,” Chemical Engineering Journal, 2011, 170, pp. 525–530. doi: 10.1016/j.cej.2010.11.026
 X. Zhu, L. Zhu, Z. Duan Z, et a1., “Comparative toxicity of several metal oxide nano-particle aqueous suspensions to zebrafish(Dardo rerio)early developmental stage,” Journal of Environmental Science and Health(Part A), Vol. 43, No. 3, 2008, pp. 278—284．
 A. J. Miao, K. A. Schwehr, C. Xu , et al., “The algal toxicity of silver engineered nanoparticles and detoxification by exopolymeric substances,” Environmental Pollution，2009，157, pp. 3034–3041. doi: 10.1016/j.envpol.2009.05.047
 E. Navarro，F. Piccapietar，B. Wanger，et al., “Toxicity of silver nanoparticles to Chlamydomonas reinhardtii,” Environ Sci Technol, 2008, 42, pp. 8959–8964. doi: 10.1021/es801785m
 V. Aruoja, H. C. Dubourguier, K. Kasemets, et al., “Toxicity of nanoparticles of CuO, ZnO and TiO2 to microalgae Pseudokirchneriella subcapitata,” Science of the Total Environment, 2 0 0 9, 4 0 7, pp. 1 4 6 1 – 1 4 6 8. doi: 10.1016/j.scitotenv.2008.10.053
 N. M. Franklin, N. J. Rogers, S. C. Apte, et al., “Comparative toxicity of nanoparticulate ZnO, bulk ZnO, and ZnCl2 to a freshwater microalga (Pseudokirchneriella subcapitata): the importance of particle solubility,” Environ. Sci. Technol, 2007,41, pp. 8484–8490. doi: 10.1021/es071445r
 C. Saison, F. O. Perreault, J. C. Daigle, et al., “Effect of core–shell copper oxide nanoparticles on cell culture morphology and photosynthesis (photosystem II energy distribution) in the green alga, Chlamydomonas reinhardtii,” Aquatic Toxicology, 2010, 96, pp. 109–114. doi: 10.1016/j.aquatox.2009.10.002
 A. Oukarroum, S. Bras, F. Perreault, R. Popovic, “Inhibitory effects of silver nanoparticles in two green algae, Chlorella vulgaris and Dunaliella tertiolecta,” Ecotoxicology and Environmental Safety, 2012, 78, pp. 80-85. doi: 10.1016/j.ecoenv.2011.11.012
 C. X. Wei, Y. B. Zhang, J. Guo, et al., “Effects of silica nanoparticles on growth and photosynthetic pigment contents of Scenedesmus obliquus,” Journal of Environmental Sciences, 2010, Vol. 22, No. 1, pp. 155–160. doi.org/10.1016/S1001-0742(09)60087-5
 I. M. Sadiq, S. Pakrashi, N. Chandrasekaran, A. Mukherjee, “Studies on toxicity of aluminum oxide (Al2O3 ) nanoparticles to microalgae species: Scenedesmus sp. and Chlorella sp.,” Nanopart Res, 2011, 13, pp. 3287–3299. doi: 10.1007/s11051-011-0243-0