粉煤灰/膨润土复合除砷吸附剂的制备及应用

Study on the Preparation and Application of Flyash/Bentonite Composite Arsenic Removal Sorbent

利用粉煤灰、膨润土和硅酸钠制备复合除砷吸附剂,研究原料配比、固化温度、固化时间、吸附时间、p H值等对其除砷性能的影响。试验结果表明:制备的除砷吸附剂可将废水中砷浓度从0.51mg/L降低到0.025mg/L,砷去除率为95.28%,出水达到GB3838-2002《地表水环境质量标准》中Ⅰ类水质的砷浓度限值要求。动态吸附试验的出水砷浓度最低降到0.059mg/L,砷去除率最高达88.43%。吸附剂对砷的吸附等温线能够用Langmuir吸附模型很好的描述,为单分子层吸附。

The composite arsenic removal sorbent was made from flyash, bentonite and sodium silicate. The effects of raw material ratio, curing temperature, curing time, absorption time and p H on arsenic removal were studied. The results show that the composite sorbent could highly decrease the As concentration in wastewater from 0.51mg/L to 0.025mg/L, and the arsenic removal ratio is up to 95.28%, achieving the groundwater environmental quality standards. The dynamic adsorption experiments show that the concentration of effluent reaches 0.059mg/L, and the arsenic removal ratio is up to 88.43%. The adsorption isotherm can be well described by Langmuir adsorption model and mono-layer molecule adsorption.