State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
Water Res. 2017 Nov 1;124:149-157. doi: 10.1016/j.watres.2017.07.051. Epub 2017 Jul 22.
Thallium (Tl) is highly toxic to mammals and relevant pollution cases are increasing world-widely. Convenient and efficient method for the removal of trace Tl from contaminated source water is imperative. Here, the removal of trace Tl by KFeO [Fe(VI)] was investigated for the first time, with the exploration of reaction mechanisms. Six different types of water treatment agents (powdered activated carbon, Al(SO), FeCl, δ-MnO, MnO nano-particles, and KFeO) were used for the removal of Tl in spiked river water, and KFeO showed excellent removal performance. Over 92% of Tl (1 μg/L) was removed within 5 min by applying 2.5 mg/L of KFeO (pH 7.0, 20 °C). XPS analysis revealed that in the reaction of Tl(I) with KFeO, Tl(I) was oxidized to Tl(III), and removed by the KFeO reduced ferric particles. The removal of Tl by in situ formed and ex situ formed ferric particle was examined respectively, and the results revealed that the removal of trace Tl could be attributed to the combination of adsorption and coprecipitation processes. The hydrodynamic size of the reduced particle from KFeO ranged from 10 nm to 100 nm, and its surface was negatively charged under neutral pH condition. These factors were conducive for the efficient removal of Tl by KFeO. The effects of solution pH, coexisting ions (Na, Ca, and HCO), humic acid, solution temperature, and reductive environment on the removal and desorption of Tl were investigated, and the elimination of Tl in polluted river water and reservoir water was performed. These results suggest that KFeO could be an efficient and convenient agent on trace Tl removal.
铊（Tl）对哺乳动物具有高度毒性，相关的污染案例在全球范围内不断增加。因此，开发一种方便、高效的方法，从受污染的水源中去除痕量 Tl 迫在眉睫。本研究首次探索了 KFeO [Fe(VI)] 去除痕量 Tl 的效果，并对反应机制进行了研究。采用粉末活性炭、Al(SO)、FeCl、δ-MnO、MnO 纳米颗粒和 KFeO 等 6 种不同类型的水处理剂去除受污染河水中的 Tl，结果表明 KFeO 具有优异的去除性能。在 pH 值为 7.0、温度为 20°C 的条件下，仅需投加 2.5 mg/L 的 KFeO，5 min 内即可去除 92%以上（1μg/L）的 Tl。X 射线光电子能谱分析结果表明，在 KFeO 与 Tl(I)的反应中，Tl(I)被氧化成 Tl(III)，并被 KFeO 还原生成的铁颗粒去除。通过考察原位生成和外加生成的铁颗粒对 Tl 的去除效果，发现痕量 Tl 的去除归因于吸附和共沉淀两种作用。KFeO 还原生成的铁颗粒的粒径范围为 10~100nm，在中性 pH 条件下带负电荷，这有利于 KFeO 对 Tl 的高效去除。此外，还研究了溶液 pH、共存离子（Na、Ca 和 HCO）、腐殖酸、溶液温度和还原环境对 Tl 去除和脱附的影响，并进行了受污染河水和水库水的除铊实验。这些结果表明，KFeO 有望成为一种高效、便捷的去除痕量 Tl 的水处理剂。
