平板炭气凝胶电极电吸附除氟

采用自制的炭气凝胶平板电极进行模拟水样中氟的电吸附去除研究,通过单因子实验优化了该电吸附技术的操作参数和适用的溶液条件,并研究了反接电极法的再生效果。研究结果表明,自制的炭气凝胶平板由纳米颗粒组成三维网络结构,比表面积为670.90 m2/g,具有良好的充放电可逆性和迅速形成表面双电层的特点。静态电吸附除氟效果最佳的条件为:水样氟离子浓度6 mg/L,pH 7.0,极板间距4 cm,电压1.6 V;共存物质硝酸根、腐殖酸、碳酸根和碳酸氢根等对氟离子的电吸附具有一定的促进作用。吸附氟离子后的炭气凝胶材料的比表面、孔体积、电容值有所减小。对于吸附氟离子后的炭气凝胶平板电极,采用反接电极法取得较好再生效果的条件为:流动状态、电压1.6 V、极板间距4 cm。再生后的炭气凝胶电极与原始炭气凝胶相比,依然具有良好的充放电可逆性。

Fluoride removal by electro-adsorption with plate carbon aerogel electrode

In this study,self-made plate carbon aerogel was used as electrodes to electro-adsorb fluoride from simulated water.Single factor experiments were conducted to optimize operating parameters and solution conditions for fluoride removal and to study fluoride desorption effectiveness with reverse electrode method.Results showed that the self-made plate carbon aerogel formed three-dimensional network structure with nano particles and its BET specific surface area was 670.90 m²/g.Moreover,this plate carbon aerogel possessed excellent reversibility of charging and discharging,and could rapidly form double electric layer on its surface.The optimum conditions for fluoride removal of the static electro-adsorption were as follows:fluorine ion concentration of 6 mg/L,pH of 7,distance between plate electrodes of 4 cm and voltage of 1.6 V.The fluoride removal was promoted when the water samples contained coexisting substances,such as nitrate,humic acid,carbonate or bicarbonate.After the electro-adsorption,the BET specific surface area,pore volume and the capacitance of plate carbon aerogel decreased.With the reverse electrode method,good regeneration effectiveness was achieved at a voltage of 1.6 V and a distance between plate electrodes of 4 cm under dynamic flow.In addition,the regenerated carbon aerogel showed good performance on the reversibility of charging and discharging in comparison with the original carbon aerogel.