Systematic and Quantitative Investigation of the Mechanism of Carbon Nanotubes鈥?Toxicity toward Algae

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• 作者：Zhifeng Long ; Jing Ji ; Kun Yang ; Daohui Lin ; Fengchang Wu
• 刊名：Environmental Science & Technology (ES&T)
• 出版年：2012
• 出版时间：August 7, 2012
• 年：2012
• 卷：46
• 期：15
• 页码：8458-8466
• 全文大小：552K
• 年卷期：v.46,no.15(August 7, 2012)
• ISSN：1520-5851

文摘

Concurrent with the increasing production and application of carbon nanotubes (CNTs) comes an increasing likelihood of CNTs presenting in the aquatic environment, and thereby potentially threatening aquatic organisms via toxic mechanisms that are, at present, poorly understood. This study systematically investigated the toxicity of three multiwalled CNT (MWCNT) samples toward a green alga (Chlorella sp.), focusing on examining and quantifying the contributions of five possible mechanisms to the algal growth inhibition. The results showed that the MWCNTs significantly inhibited the algal growth. The contribution of metal catalyst residues in the MWCNTs to the algal growth inhibition was negligible, as was the contribution from the MWCNTs鈥?adsorption of nutrient elements. The algal toxicity of MWCNTs could mainly be explained by the combined effects of oxidative stress, agglomeration and physical interactions, and shading effects, with the quantitative contributions from these mechanisms depending on the MWCNT size and concentration. At MWCNT concentrations around 96 h IC₅₀, the oxidative stress accounted for approximately 50% of the algal growth inhibition, whereas the agglomeration and physical interactions, and the shading effects each took approximately 25% of the responsibility.