Oxidation process of lead sulfide nanoparticle in the atmosphere or natural water and influence on toxicity toward Chlorella vulgaris
Oxidation process of lead sulfide nanoparticle in the atmosphere or natural water and influence on toxicity toward Chlorella vulgaris
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硫化铅纳米粒子在大气或天然水中的氧化过程及其对小球藻毒性的影响
DOI：
10.1016/j.jhazmat.2021.126016
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发表时间：
2021-05-12
影响因子：
13.6
通讯作者：
Li, Haibo
中科院分区：
文献类型：
--
作者：
Kong, Yu;Sun, Hongyu;Li, Haibo
硫化铅纳米粒子（nano-PbS）释放到环境中会对人类和生态系统造成危害。NanoPbS在环境中可能会发生氧化，但氧化机制尚不清楚。本文研究了臭氧（O3）、过氧化氢（H2 O2）和羟基自由基（HO ⋅）在大气和天然水体中对纳米PbS的氧化动力学和产物。结果表明，纳米PbS的氧化过程可分为3个阶段，依次产生铅的硫酸盐、铅的离子和铅的氧化物。O3或HO⋅与H2 O2相比，纳米PbS在初始阶段释放铅离子的速度更快，但在第二或第三阶段，二价铅转化为四价铅氧化物，从而使铅离子的释放量显著降低。以普通小球藻为例，测定了其毒性大小顺序为PbO 2 <Pb 3 O 4 <纳米PbS < PbO <PbSO 4。铅颗粒的毒性主要取决于影响细胞摄取的大小和与铅在细胞中溶解有关的溶度积常数（Ksp）。结果表明，纳米PbS的毒性在初始氧化阶段增加，并在进一步的氧化阶段降低。本研究为纳米PbS的环境行为研究提供了新的视角，为纳米PbS的生态风险评估提供了新的机理认识。
Lead sulfide nanoparticle (nano-PbS) released into environment can cause hazards to human or ecosystem. NanoPbS potentially undergoes oxidation in the environment, but oxidation mechanism is not understood yet. Herein, oxidation kinetics and products of nano-PbS by ozone (O3), hydrogen peroxide (H2O2) and hydroxyl radical (HO & sdot;) in the atmosphere or natural water were investigated. Results show that oxidation process of nano-PbS can be divided into three stages, producing sulfate, ions and oxides of lead in sequence. O3 or HO & sdot;leads to faster release of ionic lead from nano-PbS in the initial stage than H2O2, but causes significant decrease of ionic lead by transforming divalent lead to tetravalent lead oxides in the second or third stage. Toxicity determined taking Chlorella Vulgaris as an example follows an order of PbO2 < Pb3O4 < nano-PbS < PbO < PbSO4. Toxicity of lead particles is mainly determined by sizes influencing cellular uptake and solubility product constant (Ksp) related with dissolution of lead in cells. The results indicate that the toxicity of nano-PbS increases in an initial oxidation stage and decreases in further oxidation stages. This study provides new insights into environmental behavior of nano-PbS and mechanism understandings for assessing ecological risks of nano-PbS.