Nano-sized TiO2 particles containing anatase and rutile were applied to arsenic removal from water in natural groundwater conditions in the batch and column experiments. Arsenic concentrations were 200 µg L−1 and the pH range was 6–8.5 (similar to groundwater conditions). The results showed that anatase and rutile could adsorb 95.5% and 63.5% of arsenic in a solution after 60 min, respectively. In both adsorbents, arsenic adsorption was increased by increasing the adsorbent concentration. Increasing pH results increased adsorption in rutile more than anatase. The maximum adsorption capacity of 2.58 mg g−1 and 1.86 mg g−1 were calculated for anatase and rutile, respectively at the adsorbent concentration of 3 g L−1. Isotherm studies showed Freundlich model was more valid to the empirical adsorption data for both nanoparticles. The kinetics of the adsorption processes fitted well the pseudo-first-order adsorption model. To investigate the dynamic sorption, column study was carried out with fine and coarse silica sand porous media. According to the batch experiments, only anatase nanoparticles were injected into the column as an adsorbent at different doses. Breakthrough curves (BTC) showed the best efficiency of arsenic removal can be obtained by an adsorbent dose of 8 g L−1 in the fine sand column. TiO2nanoparticles (anatase and rutile) could be the effective adsorbent for reducing arsenic content from water. The kinetic of the adsorption by rutile fitted well the pseudo-first-order adsorption model. Anatase nanoparticle is more efficient than the rutile for the arsenic removal in groundwater conditions. Anatase nanoparticle could be an instrumental agent for the in situ remediation in arsenic-contaminated aquifers. TiO2nanoparticles (anatase and rutile) could be the effective adsorbent for reducing arsenic content from water. The kinetic of the adsorption by rutile fitted well the pseudo-first-order adsorption model. Anatase nanoparticle is more efficient than the rutile for the arsenic removal in groundwater conditions. Anatase nanoparticle could be an instrumental agent for the in situ remediation in arsenic-contaminated aquifers.

中文翻译：

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在类似于地下水的条件下，TiO2 纳米颗粒对砷的吸附：批量和柱状研究

在分批和柱实验中，将含有锐钛矿和金红石的纳米二氧化钛颗粒应用于天然地下水条件下水中的砷去除。砷浓度为 200 µg L-1，pH 范围为 6-8.5（类似于地下水条件）。结果表明，锐钛矿和金红石在 60 分钟后可分别吸附溶液中 95.5% 和 63.5% 的砷。在两种吸附剂中，通过增加吸附剂浓度来增加砷吸附。与锐钛矿相比，增加 pH 导致金红石中的吸附增加。在吸附剂浓度为 3 g L-1 时，计算出锐钛矿和金红石的最大吸附容量分别为 2.58 mg g-1 和 1.86 mg g-1。等温线研究表明 Freundlich 模型对两种纳米颗粒的经验吸附数据更有效。吸附过程的动力学符合准一级吸附模型。为了研究动态吸附，用细和粗硅砂多孔介质进行柱研究。根据批量实验，只有锐钛矿纳米颗粒以不同的剂量作为吸附剂注入柱中。突破曲线 (BTC) 表明，细砂柱中吸附剂剂量为 8 g L−1 时，除砷效果最好。TiO2 纳米颗粒（锐钛矿和金红石）可能是降低水中砷含量的有效吸附剂。金红石的吸附动力学符合准一级吸附模型。在地下水条件下，锐钛矿纳米颗粒比金红石更有效地去除砷。锐钛矿纳米颗粒可能是砷污染含水层原位修复的工具。TiO2 纳米颗粒（锐钛矿和金红石）可能是降低水中砷含量的有效吸附剂。金红石的吸附动力学符合准一级吸附模型。在地下水条件下，锐钛矿纳米颗粒比金红石更有效地去除砷。锐钛矿纳米颗粒可能是砷污染含水层原位修复的工具。在地下水条件下，锐钛矿纳米颗粒比金红石更有效地去除砷。锐钛矿纳米颗粒可能是砷污染含水层原位修复的工具。在地下水条件下，锐钛矿纳米颗粒比金红石更有效地去除砷。锐钛矿纳米颗粒可能是砷污染含水层原位修复的工具。