饮用水砷污染是一个世界性问题。在缺氧条件下，地下水中的砷以三价为主。与五价砷（As(V)）相比，三价砷（As(III)）毒性强，溶解度高，更难用传统水处理方法去除。本论文针对现有除砷材料和方法的不足，制备出具有不同结构和表面化学性质的新型铜基碳纳米管复合膜，并深入探究了复合膜的结构性质与除砷效果之间的关系；在此基础上，建立了阴离子交换预处理和吸附膜过滤组合的新型地下水除砷工艺。研究成果对新型膜材料的研发以及饮用水除砷技术的创新具有重要意义。 本论文的主要工作和发现如下： （i）探究了不同结构铜基碳纳米管复合膜的制备方法，初步揭示了膜结构与除砷效果之间的内在关系。利用真空抽滤、磁控溅射和真空蒸镀方法制备了具有不同结构性质的铜基碳纳米管复合膜。通过表征及简单过滤实验发现，真空抽滤和磁控溅射法可在复合膜表面形成铜或氧化铜的稳定沉积层，且铜基颗粒分布均匀致密，除砷效果较好。相比之下，真空蒸镀后，碳纳米管复合膜表面形成的铜或氧化铜沉积层结构疏松，分布不均匀，除砷效果较差。 （ii）系统研究了真空抽滤制备的纳米零价铜负载膜的除砷作用，确定其除砷机理。结果表明：（1）该复合膜的结构对As(III)去除影响较小，而纳米零价铜颗粒负载量的增加会提高As(III)的去除效率，当纳米零价铜负载量为82.2 mg m^-2时，As(III)去除率为90%以上；（2）复合膜表面和溶液中砷的形态变化表明，复合膜可直接吸附去除As(III)，或者将As(III)转化成As(V)并吸附去除；（3）原水pH、Cl^-、NO^3-、SO4^2-、HCO^3-，以及低浓度天然有机质对复合膜过滤吸附砷的影响较小，但HPO42-对砷的竞争吸附作用显著。 （iii）考察了磁控溅射镀铜复合膜的除砷效果，初步揭示其除砷机理。研究发现，镀铜复合膜的除砷途径与纳米铜负载膜相似，包括As(III)的直接吸附或As(III)氧化生成As(V)并被复合膜吸附去除。在此过程中，溅射到碳纳米管表面的纳米铜颗粒主要发挥催化氧化和吸附作用，而均匀分散的碳纳米管层有利于均匀铜镀层的形成，从而增强复合膜对As(III)的去除效率。但原水中HPO4^2-及NOM的竞争吸附作用会降低As(III)的去除效率。 （iv）针对纳米铜负载膜及磁控溅射镀铜膜除砷效果受磷酸盐影响大的缺点，制备了CuFe₂O₄负载的碳纳米管复合膜，提高其在磷酸盐存在时对As(III)的去除效率。CuFe₂O₄所含的Fe(III)可能会促进其对As(III)的氧化和吸附。因此，复合膜的结构性质及低浓度HPO4^2-（0.1 mmol L^-1）和NOM（2.5 mg L^-1）对复合膜的除砷效果影响较小。但高浓度HPO4^2-（1 mmol L^-1）或NOM（5 mg L^-1）存在时，复合膜对As(III)的去除效率降低，但仍高于负载纳米铜的复合膜和磁控溅射镀铜膜。 （v）根据吸附过滤原理，构建预处理-铜基复合膜过滤的组合工艺，探究预处理强化去除As(III)的效果和机理。在过滤过程中磷酸根离子与As(III)和As(V)存在竞争吸附作用，因此NaClO预氧化不能有效提高CuFe₂O₄/CNT复合膜对As(III)的去除效率。而阴离子交换预处理能去除地下水中90%的SO4^2-、HPO4^2-和NOM，从而消除共存物质对As(III)去除的抑制作用，提高As(III)的去除效率。阴离子交换预处理加CuFe₂O₄/CNT膜过滤的组合工艺操作简便、能耗低，在地下水除砷方面具有良好的应用前景。

Arsenic contamination of drinking water is a global issue. Under anoxic conditions, arsenic in groundwater is dominated by the trivalent species. Compared with As(V), As(III) is highly toxic and soluble in water, which makes it more difficult to remove by conventional water treatment methods. In this study, novel copper-based carbon nanotube membranes with different structures and properties were prepared and investigated for As(III) removal from groundwater. Furthermore, anion exchange pretreatment were studied for enhancing As(III) filtration by these membranes. The outcome of this research has great significance for the development of novel membrane materials and processes for drinking water purification. Major findings of this research are as follows: (i) Copper-based carbon nanotube composite membranes with different structural properties were prepared by vacuum filtration, magnetron sputtering and vacuum evaporation. Through characterization and simple filtration experiments, it was found that stable layers of copper or copper oxide could be formed on the surface of the composite membrane by vacuum filtration and magnetron sputtering, and the arsenic removal efficiencies were high. In contrast, after vacuum evaporation, the copper or copper oxide deposits formed on the surface of carbon nanotube membrane were loose and unevenly distributed, and the performance of arsenic removal was poor. (ii) The arsenic removal performance of nano-copper membranes prepared by vacuum filtration was systematically studied, and the removal mechanism was determined. The results showed that: (1) the structure of the composite membrane had little effect on the removal of As(III), while the increase of the nano-copper particles loading increased the removal efficiency of As(III). When the nano-copper loading was 82.2 mg m-2, the As(III) removal ratio was above 90%; (2) The morphological changes of arsenic on the surface of the composite membrane and the solution indicated that the composite membrane could directly adsorb As(III) or convert As(III) to As(V) and then adsorb them; (3) initial solution pH, Cl-, NO3-, SO42-, HCO3-, and low concentration of natural organic matter had little effects on the adsorption of arsenic by the composite membrane, but the presence of HPO42- played a significant competitive adsorption effect on arsenic. (iii) The performance of arsenic removal by the Cu-based membrane prepared by magnetron sputtering was investigated, and the mechanism of arsenic removal was revealed. The magnetron sputtering-prepared membranes removed As(III) in the means similar to the vacuum filtration-prepared membranes, including direct adsorption of As(III) or the oxidation of As(III) into As(V) and adsorbed by the composite membrane. In this process, the sputtered Cu particles served both as the catalysts for As(III) oxidation and as the adsorbents for As(III) and As(V) species. Meanwhile, the CNT substrate layer potentially facilitated the formation of a uniform Cu layer, and consequently, As(III) removal. However, the competitive adsorption of HPO42- and NOM also reduced As(III) removal. (iv) Considering the adverse effect of aqueous phosphate, CuFe2O4 nanoparticles having high As(III) adsorption were synthesized and loaded onto the CNT membranes via the vacuum filtration method. Subsequent filtration results showed that low concentrations of HPO42- (0.1 mmol L-1) and NOM (2.5 mg L-1) had little effects on As(III) removal by the membranes. In the presence of high concentration of HPO42- (1 mmol L-1) or NOM (5 mg L-1), As(III) removal efficiencies noticeably decreased, but were still higher than those of the aforementioned Cu/CNT membranes. (v) Based on the filtration mechanisms, the combined process of pretreatment and copper-based composite membrane filtration was constructed, and the performance of the integrated process was investigated. Preoxidation of the synthetic groundwater by NaClO was performed but did not noticeably improve As(III) removal by the CuFe2O4/CNT membrane. In contrast, anion exchange pretreatment effectively removed HPO42- and NOM from the groundwater, which led to enhanced As(III) removal. Therefore, anion exchange pretreatment was plausible for Cu/CNT membrane filtration of groundwater arsenic. This finding is of great significance to the development of next-generation, low energy consumption, groundwater purification techniques.