【作者】 曾德华； 杨琛； 陈澄宇；

【Author】 Zeng Dehua;Yang Chen;Chen Chengyu;South China University of Technology, School of Environment and Energy;South China Agricultural University, College of Natural Resources and Environment;

【机构】 华南理工大学环境与能源学院； 华南农业大学资源与环境学院；

【摘要】 异型凝聚是影响纳米塑料（NPs）在水体中的环境归趋以及生态风险的关键因素。而煤烟纳米颗粒（Soot）因其结构性质显著异于其他纳米颗粒,其与NPs的异型凝聚行为亦可能有所不同。本研究利用时间分辨动态光散射仪（TR-DLS）考察了聚苯乙烯纳米塑料（PSNPs）与Soot在水环境中的异型凝聚行为,分析颗粒浓度比、离子强度以及天然有机物对凝聚行为的影响。结果表明,PSNPs-Soot的异型凝聚行为与纳米颗粒本身的性质、颗粒浓度比以及溶液的化学性质相关。由于PSNPs与Soot表面带有很强负电荷（静电斥力）,除了1/9下,PSNPs-Soot在单价盐（NaCl）体系的临界凝聚浓度(CCC_PSNPs-Soot)值随着PSNPs/Soot浓度比的减小而略微增大;在二价盐（CaCl₂）体系中,双电层压缩以及由Soot丰富含氧官能团引起的桥连作用共同促进了PSNPs-Soot的凝聚,且CCC_PSNPs-Soot值与颗粒浓度比正相关。因此,特定电解质溶液中的CCC_PSNPs-Soot值遵循以下规律:CCC_PSNPs>CCC_PSNPs-Soot>CCC_Soot。腐殖酸（HA）存在由于空间位阻效应对单价盐体系下PSNPs-Soot的异型凝聚具有显著的抑制作用。相反,在二价盐体系中,HA的加入通过与Ca²⁺桥连作用显著促进了PSNPs-Soot的异型凝聚。此外,PSNPs与Soot之间存在疏水作用以及π-π键作用也是影响两者异型凝聚的重要原因。该研究为预测实际水体中纳米塑料与煤烟纳米颗粒的命运和风险提供了新见解。更多还原

【Abstract】 Heteroaggregation plays an important role in the fate, transport, and risk of nanoplastics in aquatic environment. This study employed time-resolved dynamic light scattering（TR-DLS） to investigate the effects of particle concentration ratio, ionic strength, and natural organic matter on the heteroaggregation of polystyrene nanoplastics（PSNPs） and soot nanoparticles（Soot）. The results indicated that the heteroaggragtion between PSNPs and Soot strongly depended on particle type, electrostatic properties, and solution chemistries, and the total critical coagulation concentration（CCC） of heteroaggregation followed the sequence of CCC_PSNPs>CCC_PSNPs-Soot>CCC_Soot, but distinct aggregation mechanism was dominated in NaCl and CaCl₂ solutions. The CCC_PSNPs-Soot values of PSNPs-Soot slightly increased due to electrostatic repulsion as the concentration ratio decreased except for 1/9, where the homoaggregation of Soot exceed the heteroaggregation. Electrostatic repulsion and bridging effect dominated the heteroaggregation of PSNPs-Soot in CaCl₂ solution, and the CCC_PSNPs-Soot values were positively correlated with the particle concentration ratio. The presence of humic acid（HA） significantly inhibited the heteroaggregation of PSNPs-Soot in NaCl solution due to the steric hindrance effect, while destabilized PSNPs-Soot by cation bridging in CaCl₂ solution. In addition, hydrophobic interactions and π-π bonding interactions between PSNPs and Soot were also important in influencing their heteroaggregation. This study provided new insights for predicting the fate and risk of NPs and Soot in aquatic environment.更多还原