【作者】 姜丹丹； 张金利； 李韡； 张铭； 韩优；

【Author】 Dandan Jiang;Jinli Zhang;Wei Li;Ming Zhang;You Han;School of Chemical Engineering and Technology,Tianjin University;The Institute of Seawater Desalination and Multipurpose Utilization;

【机构】 天津大学化工学院； 国家海洋局天津海水淡化与综合利用研究所；

【摘要】 近年来,超临界水(SCW)以其独特的性质受到人们的广泛关注,被应用于废水处理领域。但由于超临界水处理废水技术对反应器的要求苛刻并且目前对超临界水处理废水过程的反应机制研究不够完善,使得超临界水技术的发展受到了一定的限制。而基于Reax FF反应力场的反应分子动力学模拟则能为人们研究超临界水处理生物难降解废水的机理提供一种简单、方便和有效的方法。本研究以ReaxFF反应力场为基础进行了反应分子动力学模拟,分析了以苯并芘(BaP)为代表的焦化废水在超临界水降解过程中的结构变化,进而总结出超临界水气化和氧化技术降解BaP的反应机理,指出羟基在超临界水处理废水过程中的重要作用,并分析了超临界水氧化体系中活泼自由基的来源;通过对不同温度和氧气浓度下降解过程的模拟以及产物分布的分析指出温度和氧气浓度对超临界水氧化路径及产物分布的影响;通过与相同氧气浓度下单分子BaP降解路径的对比分析了BaP分子之间相互作用对降解过程的影响;此外还通过向体系中添加苯酚、吡啶和苯三种组分研究了四种物质在超临界水中的相互作用,并通过与纯BaP在超临界水中降解的对比揭示了苯酚、吡啶和苯对BaP降解的影响。该研究工作不仅为合理确定反应条件和设计超临界水处理焦化废水反应器奠定了理论基础,也为超临界水相关反应体系的研究和工业化过程提供了理论指导。更多还原

【Abstract】 In recent years, supercritical water(SCW) has drawn people’s attention due to the unique properties,and has been applied in the field of wastewater treatment. The development of the SCW technology has been restricted because of the high requirement for reactor and incomplete reaction mechanism study. However, as simple, convenient and effective methods, the molecular dynamics(MD) simulations based on ReaxFF reactive force field can be used to study the reaction mechanisms of non-biodegradable wastewater treatment using SCW method. The present work has introduced ReaxF F reactive force field to take some simulations about the SCW reactions on coking wastewater treatment using the model of benzo[a]pyrene(BaP) and has summarized the degradation mechanisms of Ba P through the analysis of structural evolutions of BaP during supercritical water gasification(SCWG) and supercritical water oxidation(SCWO) processes. The results indicate the importance of OH radicals during SCW reactions and the source of active radicals in the SCWO system. The present study also shows the effects of temperature and oxygen concentrations on the reaction paths and product distributions of SCWO system. Besides, the effects of molecular interactions between Ba P molecules and other organic molecules have been studied here. This research will not only lay a theoretical foundation for determining the reaction conditions reasonably and designing SCW wastewater treatment reactor, also provide theoretical guidance for the research and industrialization process related to the SCW reactive systems.更多还原