Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
Key Laboratory of Integrated Regulation and Resources Development on Shallow Lakes, Ministry of Education, Hohai University, Nanjing, 210098, People's Republic of China; College of Environment, Hohai University, Nanjing, 210098, People's Republic of China.
J Hazard Mater. 2018 Jan 15;342:41-50. doi: 10.1016/j.jhazmat.2017.07.041. Epub 2017 Jul 21.
Most studies investigating the influence of TiO NPs on heavy metal bioavailability have focused on the aqueous phase; however, few have examined the sediments containing more nanoparticles. Here, we investigated the effects of TiO NPs on heavy metal bioavailability in C. fluminea in sediments. The interactions between the TiO NPs and metals in sediments, the influence of TiO NPs on metals levels in aqueous phase and geochemical speciation were also explored. The results indicated the large adsorption capacity of TiO NPs and the strong adsorption affinity to metals caused the metals adsorbed on nanoparticles, which decreased the metals concentrations in water phase. Changes in metal speciation caused by metals in EXC, CAR, and IMO partly transported from sediments to TiO NPs during the aging of sediments. Heavy metals contents in C. fluminea tissues were in the order of gill>visceral mass>mantle>foot and increased with the increasing TiO NPs contents in sediments. TiO NPs enhanced the bioavailability of metals in the speciation of EXC, CAR, and IMO in sediments by the Trojan horse effects. The results can facilitate a more realistic evaluation of the environmental risks of TiO NPs to benthic organisms in heavy metal-contaminated sediments.
大多数研究都集中在水相，研究 TiO2 NPs 对重金属生物有效性的影响；然而，很少有研究关注含有更多纳米颗粒的沉积物。在这里，我们研究了 TiO2 NPs 对沉积物中 C. fluminea 重金属生物有效性的影响。还探讨了 TiO2 NPs 与沉积物中金属之间的相互作用、TiO2 NPs 对水相金属水平和地球化学形态的影响。结果表明，TiO2 NPs 具有较大的吸附能力和对金属的强烈吸附亲和力，导致金属被吸附在纳米颗粒上，从而降低了水相中金属的浓度。由于金属在 EXC、CAR 和 IMO 中的存在，导致金属的形态发生变化，部分金属从沉积物中转移到 TiO2 NPs 上，这是在沉积物老化过程中发生的。C. fluminea 组织中的重金属含量顺序为鳃>内脏>套膜>足，并且随着沉积物中 TiO2 NPs 含量的增加而增加。TiO2 NPs 通过特洛伊木马效应增强了 EXC、CAR 和 IMO 中金属的生物有效性。这些结果有助于更真实地评估重金属污染沉积物中 TiO2 NPs 对底栖生物的环境风险。
