Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1, Xikang Road, Nanjing, 210098, China.
Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, No.1, Xikang Road, Nanjing, 210098, China.
Environ Pollut. 2019 May;248:834-844. doi: 10.1016/j.envpol.2019.02.084. Epub 2019 Feb 27.
Nanoparticles (NPs), heavy metal and natural organic matter (NOM) may simultaneously exist in the aquatic environment, where they will affect the behavior of each other and may enhance their toxicities. Studies on the influences of interactions between NOM and heavy metal ions on the behavior of NPs are scarce. In this study, combined effects of Pb and HA on the aggregation behavior of TiO NPs in water environment were investigated by Dynamic light scattering (DLS) and Nanoparticle tracking analysis (NTA). The results illustrated that interactions between Pb and HA could case the aggregation of TiO NPs obviously. The concurrence of Pb and HA resulted in decreased critical coagulation concentration (CCC) and increased attachment efficiencies. Meanwhile, we found that the addition sequences of HA and heavy metal clearly influenced the aggregation kinetics of TiO NPs. At different addition sequences, the complex reaction between Pb and HA changed the surface charge of TiO NPs, and caused the different aggregation behavior which depended on the complex locations and complex sites. Furthermore, the excitation-emission-matrix (EEM) fluorescence spectra was used to verify the significant effects of the complex interactions between Pb and HA on the aggregation of TiO NPs. Our results would be significant for interpreting TiO behavior in the complicated water system. The complexation between Pb and HA promoted the aggregation of TiO NPs, meanwhile, complex locations and complex sites played an important role.
纳米颗粒（NPs）、重金属和天然有机物（NOM）可能同时存在于水环境中，它们会相互影响，并可能增强彼此的毒性。关于 NOM 和重金属离子之间相互作用对 NPs 行为影响的研究还很少。在这项研究中，通过动态光散射（DLS）和纳米颗粒跟踪分析（NTA）研究了 Pb 和 HA 对 TiO NPs 在水环境中聚集行为的联合作用。结果表明，Pb 和 HA 之间的相互作用明显导致了 TiO NPs 的聚集。Pb 和 HA 的共存导致临界聚沉浓度（CCC）降低，附着效率增加。同时，我们发现 HA 和重金属的添加顺序明显影响了 TiO NPs 的聚集动力学。在不同的添加顺序下，Pb 和 HA 之间的复杂反应改变了 TiO NPs 的表面电荷，导致了不同的聚集行为，这取决于复合物的位置和结合位点。此外，还利用激发-发射矩阵（EEM）荧光光谱验证了 Pb 和 HA 之间复杂相互作用对 TiO NPs 聚集的显著影响。我们的研究结果对解释 TiO 在复杂水系统中的行为具有重要意义。Pb 和 HA 之间的络合促进了 TiO NPs 的聚集，同时，络合位置和络合位点发挥了重要作用。
