电吸附活性炭电极制备及电吸附特性

Preparation of activated carbon electrodes and their electrosorption performances

电极的材料和制备是电吸附技术的核心。本研究进行了活性炭电极的制备、改性和表征,并分析其电吸附特性。结果表明,物理化学改性活性炭电极比表面积可达748.54 m2/g,分别是物理改性、化学改性活性炭电极的1.22和12.16倍,电吸附效果最佳。其对Na Cl紊态电吸附效果是物理改性活性炭电极的1.28倍,化学改性活性炭电极的3.75倍。对Na Cl紊态电吸附单位吸附量为7.19 mg/g,是静态吸附的8.78倍。对Na Cl、Na2SO4和Na3PO4紊态电吸附单位吸附量依次为5.94、11.83和21.47 mg/g,单位吸附量和吸附平衡时间随着被吸附离子的负电荷增加而增加。紊态电吸附过程符合一级动力学,吸附过程是由扩散机制控制的、伴随着电场作用的慢吸附过程。

Electrode materials and preparation is the core of electrosorption technology. Carbon electrodes were prepared,modified and characterized,their electrosorption performances were studied though adsorption experiments. The results showed that physically and chemically modified activated carbon electrode had the best effect. The specific surface area of physically and chemically modified activated carbon electrode was 748. 54 m2/g and the unit adsorption amount of turbulent electosorption on Na Cl was 7. 19 mg / g,which was 1. 28 times of physically modified activated carbon electrode,3. 75 times of chemically modified one and 8. 78 times of static adsorption. Unit adsorption amount and adsorption equilibrium time of turbulent electosorption on Na Cl,Na2SO4 and Na3PO4increased with the negative charge of adsorbed ions. The electrosorption process accorded with the first-order kinetics as it was a slow adsorption process controlled by diffusion and accompanied by the electric field.