活性炭孔结构对吸附除磷的影响

Effect of activated carbon pore structure on the adsorption of phosphorus

以果壳活性炭为原料,采用NaOH活化法在不同活化温度下制备改性活性炭,对改性前后活性炭的表面形貌、表面官能团、孔结构变化进行分析。基于电容去离子技术,将活性炭制备成电极材料对含磷废水进行吸附实验,探究活性炭孔结构对吸附除磷的影响。结果表明,改性后的活性炭孔隙变得发达,比表面积及中孔含量增加,微孔孔径变宽;在吸附除磷实验中,改性后活性炭由于丰富的孔隙结构增强了对磷的吸附;吸附量与活性炭孔结构参数的相关性分析结果表明,吸附量与比表面积和总孔体积在0.05水平上显著相关;根据多元线性拟合方程可知,吸附量与1.23~1.54 nm及6.22~8.15 nm范围内的孔容具有较好的线性关系,这两个区间是影响磷吸附量的有效孔径。

Taking nutshell activated carbon as raw material,modified activated carbon were prepared by NaOH activation method at different activation temperatures,and the surface morphology,surface functional groups and pore structure changes of activated carbon before and after modification were analyzed.Based on capacitive deionization,activated carbon was prepared as electrode material to carry out adsorption experiment on phosphorous-containing wastewater,and the effect of activated carbon pore structure on phosphorus removal was explored.The results show that the modified activated carbon pores become more developed,the specific surface area and mesopores content increase,the pore size of micropores become wider.In the experiment of phosphorus removal by adsorption,the modified activated carbons enhance the adsorption of phosphorus due to abundant pore structure.The correlation analysis results of adsorption capacity and typical pore structure parameters of activated carbon show that adsorption capacity is significantly correlated with specific surface area and total pore volume at the level of 0.05.According to the multiple linear fitting equation,the adsorption amount has a good linear relationship with the pore volume in the range of 1.23~1.54 nm and 6.22~8.15 nm,these two intervals are the effective pore diameters that affect the amount of phosphorus adsorbed.