饮用水中氟含量超标会严重危害人体健康。目前广泛应用的吸附法除氟工艺需要酸/碱/盐再生，存在二次污染问题。本论文以电吸附工艺为基础，提出以活性炭负载金属氧化物吸附剂为电极的新型电强化除氟工艺。通过施加正电压，能够提升吸附剂电极的除氟吸附容量和除氟速率，并获得对氟离子的吸附选择性。通过施加反向电压，可以实现吸附剂电极的清洁再生。吸附剂电极的周期性吸附脱附结果表明电极的稳定性良好，在多次吸附脱附循环后，吸附剂电极的除氟吸附容量没有降低。选择比表面积为2100 m2/g的微孔活性炭作为电极材料，进行电吸附除氟，加载电压后，活性炭电极对氟离子的吸附符合Langmuir模型，+1.6 V电压下活性炭电极对配水（氟离子+去离子水）中氟离子的饱和吸附容量为16.8 mg/g，电荷效率达到98%。研究发现，水合比（离子水合半径与离子半径之比）是影响电吸附过程中离子吸附选择性的重要因素。离子电荷数和水合比共同决定离子的电吸附选择性，氟离子由于电荷数低且水合比高，电吸附选择性最低。分别研究了以活性炭负载Fe、Ti、Zr氧化物/氢氧化物吸附剂为电极（分别简写为Fe-AC、Ti-AC、Zr-AC）的电强化除氟及再生性能。这些吸附剂电极对氟离子具有优良的吸附选择性。对吸附剂电极施加+1.2 V的电压，氢氧化钛的饱和吸附容量从31 mg/g提高到115.2 mg/g；电极中氢氧化铁的饱和吸附容量从7 mg/g提高到45 mg/g。通过对吸附剂电极施加反向电压，克服氟离子与吸附剂之间的结合力，能实现吸附剂电极的清洁再生。Fe-AC电极在-0.4 V电压下完全再生，Ti-AC电极在-1.6 V电压下完成90%的再生，而Zr-AC电极在-1.6 V电压下不能再生。针对单金属氧化物的吸附剂电极不能同时获得高吸附容量和优良再生性能的问题，论文研究了以复合金属氧化物吸附剂为电极的除氟过程。合成铁锆复合吸附剂电极（Fe-Zr-AC），金属氧化物之间的耦合显著提高了吸附剂电极的吸附除氟容量和再生性能。Fe-Zr-AC吸附剂电极的再生性能良好，在-1.2V电压下实现完全再生，且电极对氟离子的吸附容量高于单金属的锆氧化物。复合金属氧化物吸附剂电极的除氟容量高、再生性能良好，预期形成电吸附单元后，通过数量集成放大，可望形成绿色高效的饮用水除氟工艺，有巨大的应用潜力。
Excess fluoride in drinking water is a serious threat for human health. At present, the widely used adsorption method for fluorine removal requires acid-base regeneration, and there are obvious secondary pollution problems. In this paper, based on the clean electrical adsorption method, a new type of adsorbent electro-fluorination technology was proposed. By applying a positive voltage, the adsorption capacity of the adsorbent electrode for fluoride ion was increased, and the adsorption selectivity for fluoride ion was also ensured. By applying a reverse voltage, the electrode can be clean regenerated. The operation is simple and no secondary pollution occurs. The adsorption and desorption cycle of the sorbent electrode showed that the sorbent electrode had good stability and no adsorption capacity attenuation.Microporous activated carbon with a high specific surface area of 2100 m2/g was used as the electrode material. The adsorption of fluoride ion by the activated carbon electrode conformed to the Langmuir model. The saturation adsorption capacity under the voltage of +1.6 V was 16.8 mg/g, and the charge efficiency was as high as 98%. It was found that the ratio of the ion hydration radius to the ionic radius, ie the hydration ratio, is an important factor influencing the ion selectivity in the electrosorption process. The ion adsorption selectivity is determined by the ion charge number and the hydration ratio. The fluoride ion has the lowest selectivity due to its low charge number and high hydration ratio.Electrochemically enhanced defluorination and regeneration of Fe-AC, Ti-AC and Zr-AC electrodes were investigated. Different adsorbent electrodes have good adsorption selectivity for fluoride ions. By applying a polarization voltage of +1.2 V, the adsorption capacity of the adsorbent for fluorine ions can be significantly improved. The saturated adsorption capacity of titanium hydroxide can be increased from 31 mg/g to 115.2 mg/g; the saturated adsorption capacity of iron hydroxide can be increased from 7 mg/g to 45 mg/g; By applying a reverse voltage, the electrode is regenerated by overcoming the binding force between the fluoride ion and the adsorbent, and the results show that the regeneration of the adsorbent with a high adsorption capacity is difficult. The Fe-AC electrode can be regenerated at a voltage of -0.4 V. The Ti-AC electrode is 90% regenerated at -1.6 V, while the Zr-AC electrode cannot be regenerated at -1.6 V.In view of the problem that the single metal oxide adsorbent electrode cannot take into account both the adsorption capacity and the regeneration performance, the idea of the composite metal oxide sorbent electrode is proposed in this paper. The Fe-Zr-AC composite adsorbent electrode was synthesized. The adsorption capacity and regeneration performance of the composite electrode were significantly improved by the coupling effect between the metals. The Fe-Zr-AC composite electrode has higher fluoride adsorption capacity than single metal Zr-AC electrode, and the electrode regeneration performance is excellent at a voltage of -1.2 V.The composite metal oxide sorbent electrode has the advantages of good fluoride removal and regeneration performance. After the formation of electro-adsorption modules in the future, it will probably replace traditional adsorption methods through quantitative amplification and become an efficient drinking water fluoride removal process，would be applied in broad prospects.
