粉煤灰吸附除磷的改性研究

Adsorption of phosphate using modified fly ash from water solution

研究了粉煤灰的最佳改性条件及其吸附理论模型。获得了粉煤灰用于吸附含磷量为5 mg P/L的模拟二级出水的3种改性的最佳条件(21℃):(1)0.25 mol/L盐酸改性的粉煤灰对磷的去除率为76.0%,出水含1.20 mg P/L;(2)300℃下煅烧的粉煤灰对磷的去除率为93.8%,出水中磷含量达到了0.31 mg P/L;(3)低火(119 W)改性的粉煤灰的磷去除率达95.4%,出水含0.23 mg P/L。试验结果表明:Langmuir方程能很好地解释两种改性粉煤灰的吸附动力学(R2=0.9188,S.E=0.0032),而Simple Elovich方程在描述两者的吸附动力学试验数据上显示出优越性(R2=0.9427,S.E=0.029)。

The optimal conditions of different modification and the theoretical adsorption models were studied. The optimal modification conditions of acid treatment, thermal treatment and microwave activation for fly ash （FA） used in treating artificial secondary effluent （5 mg P/L） were determined, （1） the phosphate removal efficiency of FA activated by 0. 25 mol/L HCl is 76.0% with the effluent containing 1.20 mg P/L. （2） FA calcined at 300 ℃ remove 93.8% of phosphate, remaining 0. 23 mg P/L. （3） FA modified by microwave at 119 W possess 95.4% phosphate removal efficiency with 0. 23 mg P/L residue. The results showed that the Langmuir Equation provides better fittings in terms of R^2 and S. E values（R^2 =0. 9188,S. E =0. 0032） and the Simple Elovich Equation can describe the adsorption data better （R^2 = 0. 9427, S. E = 0. 029）.