腐殖酸广泛存在于环境，其结构的复杂性和不同环境腐殖酸的非同质性使得完全依赖实验进行与其相关的界面机制探索陷入困境；而其参与形成的复杂界面体系因具有典型自组装特性和相行为，使得难以采用量化和全原子分子动力学等常规计算手段进行研究。腐殖酸参与的环境界面形成规律和污染物界面行为机制仍是困扰领域研究的一个难点。本项目提出以整合全原子模型与粗粒化模型为依托，建立基于量化计算、分子动力学模拟和耗散粒子动力学分析等不同尺度计算手段集成的新方法以突破研究瓶颈，构建链接微观与介观的腐殖酸参与界面体系多尺度化学模型，并辅以必要实验验证。项目拟以环境危害大且结构各异的持久性有毒物质为界面研究探针分子，阐明水-腐殖酸等复杂体系自组装形成多种界面的化学机制，诠释不同结构特征腐殖酸、体系含水率、共存无机固相组分等对界面形成和污染物界面行为的影响，回答腐殖酸参与的典型环境界面形成与污染物界面行为化学机制这一领域难题。

Humic acid (HA) is ubiquitous in environment. Intensive efforts have been made to find the effective ways to assess the HA-involved interfacial behavior of contaminants since it is one of the important criteria to evaluate the migration, persistency and bioavailability of organic pollutants in the environment. However, the underlying mechanism of interface formation and pollutant interfacial behavior is still unclear due to the structure complexity and environmental heterogeneity of HA even with the aid of advanced analytical methods. As HA presents several characteristics of soft matter such as self-assembly and phase equilibrium, quantum mechanics (QM) calculation and all-atom molecular dynamics (MD) simulations are not suitable for analyzing HA-involved interface assembly, a mesoscopic issue presenting features of soft matter. This study is an effort aiming to break the methodology bottleneck by integrating all-atom models with coarse-grained (CG) ones and developing a novel computation method coupling various calculation techniques from different scales, such as QM, MD, and dissipative particle dynamics (DPD), to establish multiscale models linking the molecular level with the mesoscopic scale of an environmental interface problem. Moreover, with the aid of selected probes from typical persistent toxic substances (PTS) of various structural features, the chemical mechanism of interface formation for the water-HA system will be elucidated by DPD analysis and subsequent local QM calculations. The role of HA structural feature, water content, coexisting inorganic solid component on the interface formation and pollutant interfacial processes will then be discussed. The necessary experimental analysis will also be adopted to verify the predicted environmental parameters such as density, adsorption capacity and diffusion coefficient. The project not only helps to reveal the molecular mechanism of HA-involved interface formation, annotate the structural basis of the HA-involved interfacial behavior of environmental pollutants, but also provide a new tool of high efficiency for assessment of the mobility and interfacial behavior of organic chemicals in the environment.