最近，随着氧化阴离子铬酸盐（HCrO₄^-/CrO₄^2-）的出现，砷酸盐 （H₂AsO₄-/HAsO₄^2-）和高氯酸盐（ClO₄^-）；以及它们的污染和自然污染 作为一个重要的饮用水水质问题，要仔细评估 采用膜技术去除痕量无机污染物。A. 实验室规模的横流平板过滤装置已用于评估输送 单价和/或二价氧阴离子（HCrO₄^-/CrO₄^2-，H₂AsO₄^- /HAsO₄^2-， 以及通过带负电荷的反渗透（RO）、纳滤（NF）和 紧密超滤（UF）膜和扩散池测试装置已用于 研究氧阴离子在空气中通过膜孔的传输（通过阻碍扩散） 各种水化学条件。 在本研究中，对RO、NF和紧密超滤膜进行了测试，以评估 pH值和电导率（离子强度）对这三种有毒物质的传输/排斥的影响 氧阴离子。这项研究调查了铬酸盐的运输（排斥）机制， 砷酸盐和高氯酸盐，包括溶液扩散、空间（尺寸）排斥和/或 RO、NF和紧密超滤膜的静电排除。 目标阴离子根据分子量、水合度进行表征 离子半径（大小）和在水中的扩散系数（Dw）。一种扩散池，包含 实际RO、NF和紧密超滤膜样品已被用于估算包含各种溶质-膜相互作用的阻碍扩散（Dp），并测量了阻碍扩散 扩散系数比相应的扩散系数小几个数量级 在水中的系数，从而证明了静电和空间位阻的重要性 微量阴离子排斥的障碍。包括11个参考文献、表格、图表。

With the recent emergence of oxyanions chromate (HCrO₄^-/CrO₄^2-), arsenate (H₂AsO₄^-/HAsO₄^2-), and perchlorate (ClO₄^-); and their contamination and natural occurrence as an important drinking water quality issue, a careful assessment of membrane technology for trace inorganic contaminants removal has been performed. A bench-scale cross-flow flat-sheet filtration unit has been used to evaluate the transport (rejection) of mono-valent and/or divalent oxyanions (HCrO₄^-/CrO₄^2-, H₂AsO₄^-/HAsO₄^2-, and ClO₄^-) through negatively charged reverse osmosis (RO), nanofiltration (NF), and tight ultrafiltration (UF) membranes, and a diffusion cell testing unit has been used to investigate oxyanion transport (by hindered diffusion) through membrane pores under various water chemistry conditions. In this study, RO, NF and tight UF membranes have been tested to evaluate the effects of pH and conductivity (ionic strength) on the transport/rejection these three toxic oxyanions. The study investigated the transport (rejection) mechanisms of chromate, arsenate, and perchlorate including solution diffusion, steric (size) exclusion, and/or electrostatic exclusion for RO, NF and tight UF membranes. The target anions were characterized according to molecular mass, hydrated ionic radius (size), and diffusion coefficient in water (Dw). A diffusion cell containing actual RO, NF, and tight UF membrane specimens has been used to estimate hindered diffusion (Dp) embodying various solute-membrane interaction, with measured hindered diffusion coefficients several orders of magnitude less than corresponding diffusion coefficients in water, thus demonstrating the importance of electrostatic and steric hindrance in trace anion rejection. Includes 11 references, table, figures.