【作者】 方齐乐；

【导师】 陈宝梁；

【作者基本信息】 浙江大学 ， 环境科学， 2014， 博士

【摘要】 高氯酸盐(C104-)作为一种新型的持久性环境微量污染物,因其抑制机体甲状腺激素分泌并引发一系列代谢和发育疾病,尤其对育龄女性和婴幼儿的干扰异常显著,从而成为环境领域的研究热点之一。C1O4-具有广泛的人为源和普遍的自然源,污染现状尤为严峻；然而目前的调查主要集中在美国,其他国家因研究刚起步,C104-浓度水平调查数据十分有限。高溶解性、强稳定性和快速迁移性等特点不仅使C104-对人体健康和生态安全构成严重威胁,也使其污染控制与修复存在较大难度。论文在简介C104-污染现状、健康风险及其控制技术的基础上,重点评述了不同类型吸附材料对C104-吸附性能和去除机制的研究进展。针对C104-吸附材料制备条件严苛且设计不系统,C104-在材料界面吸附机制和调控因素尚未阐明等问题；本研究在调查水体(地表水和自来水)和大气环境中C104-浓度水平与来源的同时,改性制备了典型的碳质材料(生物碳、碳纳米管、石墨烯)和矿质材料(不同类型与负载量的有机膨润土),利用XPS、XRD、FTIR、 Raman光谱、SEM、Zeta电位、元素分析、比表面积测定和有机碳含量测定等手段表征材料的结构特征、微观形貌和表面性质；系统研究了不同吸附材料对C104-的吸附性能及影响因素,结合吸附前后的结构表征,探讨了C104-在不同材料界面上的作用机制,并建立吸附材料基体、表面性质与吸附性能之间的定量构-效关系。研究结果为设计和制备功能吸附材料、经济高效去除C104-提供理论依据与技术支撑。论文的主要创新性结论如下：(1)通过实际调查与测定首次发现不同消毒工艺对自来水中Cl04-浓度水平的影响。结果表明,臭氧和液氯消毒对饮用水中C104-浓度无影响；而C1O2和NaClO消毒会显著增加出厂水中Cl04-浓度水平,因为两者均可作为C104-形成的活性前体物质,这在以往的研究中被忽略；该结果为重新进行饮用水的安全管理提供理论参考。同时提出人为的烟花燃放活动不仅给大气带来高强度C104-污染,在干／湿沉降的迁移辅助下,也会使地面水C104-污染显著加剧。(2)提出了氢键作用在碳质材料吸附C104-中的相对贡献及其调控因素,阐明了碳质材料的基体和表面性质对C104-绑定的决定性作用。由废弃的生物质材料通过裂解温度的控制制备得到一系列具有不同结构特征和表面性质的生物碳材料,发现高温裂解得到的生物碳不仅适用范围广,且呈现优越的C104-吸附能力并可简易再生。高温生物碳因其疏水性表面和芳香性基体进一步强化含氧官能团对ClO4-的氢键绑定。通过碳基纳米材料碳纳米管和石墨烯的可控改性,证实了碳质材料的界面性质决定着其特定吸附位点的可获得性,疏水性界面有助于吸附位点的暴露并与C104-接触：材料表面的含氧官能团(羟基和羧基)则是C104-吸附绑定的主要位点,而溶液pH值会显著影响这两类官能团的存在形态,并主导着静电引力和氢键作用对C1O4-的吸附贡献。因此,可通过调控碳质材料的基体(芳香性/脂肪性)和表面性质(官能团含量/亲疏水性),以及溶液条件(pH值/共存离子),从而设计碳质材料实现最佳的C104-吸附去除。(3)证实了非常规蓝移氢键在C104-吸附绑定中的作用及其调控因素,建立了有机改性膨润土上阳离子表面活性剂负载量与其吸附能力之间的定量化关系。长碳链阳离子表面活性剂(十六烷基三甲基溴化铵,CTMAB)改性的有机膨润土具有很强的C104-吸附能力,且CTMAB负载量越高,吸附能力越强,两者呈很好的线性关系,实现了吸附材料的可控制备。在有机膨润土纳米层间域,除了常规的离子交换或静电引力外,光谱信息和量子化学计算均证实C104-与CTMAB上[(CH3)3N+-]中的C-H形成了非常规蓝移氢键并以三重成键的构型键合；且可通过纳米层间的亲疏水程度来定量控制蓝移氢键的吸附贡献,疏水性微环境中蓝移氢键的吸附贡献是亲水环境的5.6倍。更多还原

【Abstract】 Perchlorate (ClO4-), as an emerging persistent and trace pollutant, has become one of the research hotspots in environmental field, because it can inhibit the secretion of thyroid hormone in organism and then cause various metabolic or developmental diseases, especially for the women of childbearing age and infant. Due to its broad anthropogenic source and universal natural origin, ClO4-contamination has been very serious, however, the current investigation was mainly limited in America, and the survey data about ClO4-level was extremely deficient in other countries. With the properties of high solubility, strong stability and fast mobility, ClO4-not only poses a great risk for human health and ecological safety, but also makes it hard for the control and remediation of ClO4-polluted environments. On the basis of brief introduction about the contamination status, health risk, and control technologies of ClO4-, the progresses of ClO4-adsorption onto different type of materials were particularly reviewed, including their removal capacities and adsorption mechanisms. In view of the tough conditions and unsystematic design in the preparation of ClO4-adsorption materials, and the unclear recognition of the adsorption mechanisms and regulation factors of ClO4-onto the interface of materials, this dissertation firstly carried out the concentration levels and sources survey of ClO4-in water (surface water and tap water) and air. Then, typical carbonaceous materials (biochar, carbon nanotubes, and graphene) and mineral materials (organobentonites modified with different types and loading-amount of surfactants) were synthesized. Their structural properties were characterized via XPS, XRD, FTIR, Raman spectra, SEM, Zeta potential, elemental analysis, the specific surface area and organic carbon content. In addition to the systematic test of the adsorption capacity and influential factors of the obtained materials for ClO4-, the molecular interaction mechanisms of ClO4-on different material interfaces were deeply investigated according to the structural evolvement before and after ClO4adsorption. The quantitative relationships between the adsorption capacities and material structures (including matrix and surface properties) were established, which provide a theoretical basis and an engineering reference for designing novel and high-efficient adsorption materials for ClO4-removal. The main original conclusions of this work are drawn as follows:(1) The effect of disinfection process on ClO4-concentrations in the tap water was first discovered through the field survey. Results showed that disinfection using ozone and liquid chlorine did not affect the C1O4-concentrations in drinking water, while disinfection using ClO2and NaClO would significantly increase the ClO4-concentration in water, which was mainly resulted from that both of them can act as the active precursor of C1O4-formation. This observation usually ignored in previous studies should be paid attention for drinking water safety management. Meanwhile, the pollution contribution of human fireworks was also elucidated, which not only brought high C1O4-pollution to the air, but also significantly increased the ClO4-contamination in surface water via the dry and wet depositions.(2) Hydrogen bonding and its regulating factors contributed to C1O4-adsorption onto carbonaceous materials were proposed, and the dominant roles of the matrix and surface properties of the carbonaceous materials for ClO4-binding were clearly illustrated. A series of biochars with different structures and properties were prepared from the waste biomass via pyrolysis under different temperatures. It was found that high-temperature derived biochars not only had a broad scope of application, but also behaved superior adsorption capacity for ClO4-and can be easily regenerated. The hydrophobic surface and aromatic matrix of high-temperature biochars can further enhance the hydrogen bonding derived from the surface oxygen-containing groups for ClO4-binding. Carbon nanomaterials of carbon nanotubes and graphene were controllably modified and used for ClO4-adsorption, which demonstrated that the interface property of carbonaceous materials determined the availability of their adsorption sites and a hydrophobic interface will help to expose the sites for ClO4-binding. Furthermore, surface oxygen-containing functional groups (hydroxyl and carboxyl) were the main adsorption sites, whose forms were largely dependent on the solution pH and dominated the contribution of electrostatic attraction and hydrogen bonding for ClO4-adsorption. Thus, the carbonaceous materials can be designed through the regulation of matrix (aromatic/aliphatic) and surface (functional groups/hydrophobic) of materials as well as the solution conditions (pH and co-existing ions), achieving the optimal removal of ClO4-(3) The non-conventional blue-shift hydrogen bonding (BSHB) involved in ClO4-binding and its influential factors were first verified, and a quantitative relationship between the loading amount of cationic surfactant and adsorption capacity of organobentonites was established. The modification using cationic surfactant with long chain (cetyltrimethylammonium bromide, CTMAB) made the obtained organoclay behave high adsorption capacity for ClO4-, and the adsorption capacity will be improved with the increase of the loading amount of CTMAB, which presented good linear relationship between them and reached the controllable preparation of adsorption materials. In the nano-interlayer of organobentonite, besides the ion-exchange and electrostatic attraction, non-conventional BSHB formed between ClO4-and C-H from [(CH3)3N+-] on CTMAB was demonstrated through spectral information and quantum chemical calculations, and the BSHB were bonded in configuration of triple forms. It can be quantitatively controlled of the adsorption contribution of BSHB via the adjustment of the hydrophilic or hydrophobic degree of nano-interlayer, and the contribution of BSHB for ClO4-adsorption in hydrophobic micro-environment was5.6time of that in hydrophilic micro-environment.更多还原