Adsorption of pharmaceuticals and personal care products in hydrophobic zeolites

药品和个人护理产品(PPCP)是一类新出现的污染物，由于其广泛存在并对健康和环境产生潜在的负面影响，因此受到特别关注。已在各种自然环境中检测到PPCPs，包括城市和工业废水、地表水、地下水和沉积物。由于常规废水处理厂不是为去除PPCP而设计的，因此为此目的探索了其他几种备选方案，其中之一是基于吸附的工艺。尽管碳基吸附剂的研究最为深入，但疏水沸石(具有高硅铝比直到全硅组成)也表现出一些重要的优点，最突出的是稳定性高，对天然有机物的共吸附可以忽略不计。虽然许多研究小组已经在实验上研究了PPCP在高硅沸石上的吸附，但大多数研究集中在一种或几种沸石-PPCP组合上。由于缺乏系统的研究，对于对感兴趣的PPCP(或一组PPCP)合理选择合适的沸石吸附剂的指导方针很少。计算模拟技术可以提供洞察孔拓扑结构和吸附性能之间关系的能力，但在这一领域几乎没有人利用。该项目将使用分层的计算-实验相结合的方法来研究PPCPs在疏水沸石中的吸附。在第一部分中，基于力场的计算被用于筛选许多沸石-PPCP组合，考虑了大约30到40个PPCP和10到15个不同的沸石。液相吸附的直接模拟将针对组合的子集进行。在第二部分中，色散校正密度泛函理论计算(DFT-D)将被用来更深入地研究沸石-PPCP的组合，例如，从主导相互作用和吸附诱导的变形的角度。最后，选择两个或三个组合进行实验研究。这些实验研究将包括液相吸附实验，以及使用衍射法、热重法和不同的光谱技术对负载PPCP的沸石样品进行多方法表征。该项目的筛选部分旨在展示相对廉价的模拟如何能够在不需要费力的实验的情况下识别有前景的沸石-PPCP组合。这种基于模型的方法的能力的展示，通过对选定案例的实验验证，应该会对未来与沸石去除PPCP的应用相关的研究产生重大影响。DFT-D计算和PPCP负载样品的全面实验表征将有助于从根本上理解复杂有机分子在沸石中的吸附，这在各个领域都是相关的。

Pharmaceuticals and personal care products (PPCPs) are a group of emerging contaminants of particular concern due to their widespread occurrence and potential negative effects on health and environment. PPCPs have been detected in various natural environments, including urban and industrial wastewaters, surface waters, groundwater, and sediments. As conventional wastewater treatment plants were not designed for the removal of PPCPs, several other options have been explored for this purpose, one of them being adsorption-based processes. Although carbon-based adsorbents have been most intensively investigated, hydrophobic zeolites (with high Si/Al ratios up to all-silica composition) also present some important advantages, most prominently high stability and negligible co-adsorption of natural organic matter. While a number of groups have investigated the adsorption of PPCPs in high-silica zeolites experimentally, most studies focused on one or a few zeolite-PPCP combinations. Due to a lack of systematic investigations, there are few guidelines for a rational choice of a suitable zeolite adsorbent for a PPCP (or group of PPCPs) of interest. The capabilities of computational modelling techniques, which can deliver insights into the relationships between pore topology and adsorption properties, have hardly been exploited in this area.The project will use a hierarchical, combined computational-experimental approach to study the adsorption of PPCPs in hydrophobic zeolites. In the first part, force-field-based calculations are used for a “screening” of many zeolite-PPCP combinations, considering about 30 to 40 PPCPs and 10 to 15 different zeolites. Direct simulations of liquid-phase adsorption will be performed for a subset of combinations. In the second part, dispersion-corrected density functional theory calculations (DFT-D) will be used to study zeolite-PPCP combinations of interest in more depth, e.g., in terms of dominant interactions and adsorption-induced deformations. Finally, two or three combinations will be selected for experimental study. These experimental investigations will comprise liquid-phase adsorption experiments as well as a multi-method characterisation of PPCP-loaded zeolite samples using diffraction, thermogravimetry, and different spectroscopic techniques.The screening part of this project aims to show how relatively inexpensive simulations can permit the identification of promising zeolite-PPCP combinations without the need for laborious experiments. The demonstration of the capabilities such a modelling-based approach, validated through experiments for selected cases, should have a significant impact on future application-related studies of zeolites for PPCP removal. The DFT-D calculations and the thorough experimental characterisation of PPCP-loaded samples will contribute to the fundamental understanding of the adsorption of complex organic molecules in zeolites, which is relevant in various fields.