State Environmental Protection Key Laboratory of Wetland Ecology and Vegetation Restoration, School of Environment, Northeast Normal University, Changchun 130117, PR China.
Department of Civil and Environmental Engineering, Clarkson University, Potsdam, NY, USA.
J Hazard Mater. 2024 Nov 5;479:135718. doi: 10.1016/j.jhazmat.2024.135718. Epub 2024 Sep 2.
The widespread use of rubber antioxidants, especially p-phenylenediamines (PPDs), has raised increasing concerns about their risk assessment. However, there is a notable lack of research on their transformation products (TPs). Photolysis, influenced by active components, plays a significant role in the environmental fates of PPDs. This study investigated four emerging PPDs (N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6PPD), N, N'-diphenyl-p-phenylenediamine (DPPD), N-isopropyl-N'-phenyl-p-phenylenediamine (IPPD), and N-cyclohexyl-N'-phenyl-p-phenylenediamine (CPPD)) through a combination of experiments (photolysis kinetics, quenching experiments, acute toxicity test to Vibrio Fischeri (V. fischeri) and identification of photolytic products) and theoretical calculations. The results revealed different pathways for indirect photolysis mediated by the hydroxyl radicals (•OH) and singlet oxygen (O) of DPPD and IPPD under simulated sunlight irradiation. The effects of dissolved organic matter (DOM) and fulvic acid (FA) on the rates of photolysis of PPDs highlighted the complex interactions among the molecular structure, light absorption properties, and environmental variables. Quenching for reactive oxygen species (ROS) reduced photo-induced toxicity, whereas the addition of DOM and FA increased it, suggesting the crucial role of ROS in the formation of more toxic photolytic products. The study of photolysis pathways and the evaluation of the health risks provide a comprehensive understanding of the environmental effects of these pollutants.
橡胶抗氧剂，特别是对苯二胺（PPD）的广泛使用引起了人们对其风险评估的日益关注。然而，关于它们的转化产物（TPs）的研究却很少。光解作用受活性成分的影响，在 PPDs 的环境命运中起着重要作用。本研究通过实验（光解动力学、猝灭实验、对发光菌（V. fischeri）的急性毒性测试和光解产物的鉴定）和理论计算相结合，研究了四种新兴的 PPDs（N-（1,3-二甲基丁基）-N'-苯基对苯二胺（6PPD）、N,N'-二苯基对苯二胺（DPPD）、N-异丙基-N'-苯基对苯二胺（IPPD）和 N-环己基-N'-苯基对苯二胺（CPPD））。结果表明，在模拟阳光照射下，DPPD 和 IPPD 的间接光解分别由羟基自由基（•OH）和单线态氧（O）介导，存在不同的途径。溶解有机物（DOM）和富里酸（FA）对 PPDs 光解速率的影响突出了分子结构、光吸收特性和环境变量之间的复杂相互作用。活性氧物质（ROS）的猝灭降低了光诱导毒性，而 DOM 和 FA 的添加增加了光诱导毒性，这表明 ROS 在形成更有毒的光解产物方面起着至关重要的作用。光解途径的研究和健康风险的评估提供了对这些污染物环境影响的全面了解。
