School of Space and Environment, Beihang University, No. 37, XueYuan Road, HaiDian District, Beijing 100191, PR China.
School of Space and Environment, Beihang University, No. 37, XueYuan Road, HaiDian District, Beijing 100191, PR China.
Environ Pollut. 2018 May;236:962-970. doi: 10.1016/j.envpol.2017.10.082. Epub 2017 Nov 11.
Although the risk of graphene materials to aquatic organisms has drawn wide attention, the combined effects of graphene materials with other contaminants such as toxic metals, which may bring about more serious effects than graphene materials alone, have seldom been explored. Herein, the effects of graphene (GN) and graphene oxide (GO, an important oxidized derivative of graphene) on copper (Cu) toxicity to Daphnia magna were systematically investigated. The results indicated that GN remarkably increased the Cu accumulation in D. magna and enhanced the oxidative stress injury caused by Cu, whereas did not significantly alter D. magna acute mortality within the tested Cu concentrations (0-200 μg L). On the contrary, GO significantly decreased the Cu accumulation in D. magna and alleviated the oxidative stress injury caused by Cu. Meanwhile, the presence of GO significantly reduced the mortality of D. magna when Cu concentration exceeded 50 μg L. The different effects of GN and GO on Cu toxicity were possibly dependent on the action of surface oxygenic functional group. Because of the introduction of surface oxygenic functional groups, the adsorption ability to metal ions, stability in water and interaction mode with organisms of GO are quite different from that of GN, causing different effects on Cu toxicity. This study provides important information on the bioavailability and toxicity of heavy metals as affected by graphene materials in natural water.
尽管石墨烯材料对水生生物的风险引起了广泛关注，但石墨烯材料与其他污染物（如有毒金属）的联合效应可能比单独的石墨烯材料带来更严重的影响，这方面的研究却很少有人探讨。在此，本文系统研究了石墨烯（GN）和氧化石墨烯（GO，石墨烯的一种重要氧化衍生物）对大型溞（Daphnia magna）铜毒性的影响。结果表明，GN 显著增加了大型溞体内的铜积累，并增强了铜引起的氧化应激损伤，而在测试的铜浓度（0-200μg/L）范围内，GN 对大型溞急性死亡率没有显著影响。相反，GO 显著降低了大型溞体内的铜积累，减轻了铜引起的氧化应激损伤。同时，当铜浓度超过 50μg/L 时，GO 的存在显著降低了大型溞的死亡率。GN 和 GO 对铜毒性的不同影响可能取决于表面含氧官能团的作用。由于表面含氧官能团的引入，GO 对金属离子的吸附能力、在水中的稳定性以及与生物体的相互作用方式与 GN 有很大的不同，从而对铜毒性产生不同的影响。本研究为天然水中重金属的生物可利用性和毒性受石墨烯材料影响提供了重要信息。
