改性麦草秸秆对水中磷酸根吸附效果的研究

Adsorption of phosphate from aqueous solution by modified wheat residue

为实现农作物秸秆资源化，解决水体富营养化问题，将麦草秸秆化学改性成一种可以有效吸附水体中磷酸根的阳离子型吸附剂．考察了吸附剂投加量、磷酸根溶液初始pH、温度等因素对吸附效果的影响，分析了改性麦草秸秆对磷酸根的吸附动力学过程和吸附机理．结果表明，在吸附剂投加量为4g·L^11和磷酸根溶液初始pH为4．0～7．5条件下，改性麦草秸秆对磷酸根的吸附效果最好，去除率均高于90％；改性麦草秸秆对磷酸根的吸附符合Freundlich等温模式，饱和吸附容量为2．38mmol·g^-1；吸附过程符合一级反应动力学方程，为快速反应过程；反应活化能为12．6kJ·mol^-1，反应速率对温度的变化不敏感．

To make wheat residue recyclable and remove phosphate from water and wastewater, wheat residue was modified into an anion exchanger. Its adsorption ability for phosphate was systematically examined through batch experiments. The results indicated that the modified wheat residue adsorbed phosphate effectively. It could reach the best phosphate removal results at 4 g·L^ -1 of adsorbent dosage and pH range of 4.0 ～ 7.5. The adsorption data fitted the Freundlich adsorption isotherm and the maximum adsorption capacity was 2.38 mmol·g^-1. The adsorption process fitted the first order reaction equation and the active energy was 12.6kJ·mol^-1.