吸附技术是去除水中砷的首选方法之一 小型饮用水系统。由于成本低，表面积大， 活性氧化铝是首选的吸附剂。然而，吸附过程 使用活性氧化铝对pH值敏感，砷酸盐的最佳pH值 移除范围为5.5到6.0。因为大多数地下水的pH值都在上面 在这个范围内，水处理厂必须经常在吸附过程之前调整pH值。 这种影响很可能是由于砷（V）或其他可分解物质的吸附减少 阴离子随着pH值的增加和吸附剂表面电荷的减少而减少 积极乐观的尽管纯伽马氧化铝（晶体）的等电点（pHiep） 许多活性氧化铝的形态为8.0，当质量比 吸附质与吸附剂表面积之比为164 ug/m2，导致不利的pH值 在大多数水处理方案中去除砷酸盐的范围。虽然这种影响 在大多数吸附介质中都会发生这种情况，材料的pHiep高于活性介质 氧化铝在饮用水的典型pH值下具有较高的砷酸盐吸附能力 水（pH=6.0~8.0）。铝酸镁尖晶石（pHiep=10.2）由以下方法制备: 研究了一种溶胶-凝胶工艺，并将其用作砷酸盐吸附剂，以克服这种pH效应。 这种尖晶石提供了更大的砷酸盐吸附量（每平方米吸附的砷酸盐g） 活性表面）比氧化铝（pHiep）在典型饮用水pH范围内 =8.0）通过类似工艺制备。包括34个参考文献、表格和图表。

Adsorption technologies are one of the preferred methods for removing arsenic in small-scale drinking water systems. Because of its low cost and high surface area, activated alumina has been the preferred adsorbent. However, adsorption processes employing activated alumina are sensitive to pH, with the optimum pH for arsenate removal ranging from 5.5 to 6.0. Because the pH of most groundwaters lies above this range, water treatment plants must often adjust pH prior to the adsorption process. This effect is most likely due to a decrease in adsorption of As (V) or other protolyzable anions as the pH increases and the surface charge of the adsorbent becomes less positive. Even though the isoelectric point (pHiep) of pure gamma alumina (the crystal form of many activated alumina) is 8.0, its pHiep shifts to 6.0 when the ratio of mass of adsorbate to surface area of adsorbent is 164 ug/m2, resulting in an unfavorable pH range for arsenate removal in most water treatment scenarios. Although this effect will occur with most adsorption media, materials having higher pHiep than activated alumina have higher arsenate adsorption capacities at pH values typical of drinking water (pH = 6.0 ~ 8.0). Magnesium aluminate spinel (pHiep = 10.2) was prepared by a sol-gel process and investigated as an arsenate adsorbent to overcome this pH effect. This spinel provides greater arsenate adsorption (g of arsenate adsorbed per m2 of active surface) over the pH range of typical drinking water than does *-alumina (pHiep = 8.0) prepared by a similar process. Includes 34 references, table, figures.