Fe_(3)O_(4)/活性炭的制备及其对Cr(Ⅵ)的吸附研究

The Preparation of Fe_(3)O_(4)/Activated Carbon and Its Adsorption on Cr(Ⅵ)

采用化学共沉淀法对活性炭进行改性,制备出磁性Fe_(3)O_(4)/活性炭。通过扫描电子显微镜(SEM)、傅里叶变换红外光谱仪(FTIR)和X射线衍射仪(XRD)研究对改性活性炭进行分析,结果显示Fe_(3)O_(4)成功地负载到活性炭上。用Fe_(3)O_(4)/活性炭吸附模拟废水中的Cr(Ⅵ),考察Cr(Ⅵ)的初始浓度、活性炭投加量、吸附时间、吸附温度和pH值对吸附性能的影响,并对磁性Fe_(3)O_(4)/活性炭进行回收和再生。结果表明,最佳吸附条件如下:Cr(Ⅵ)初始浓度为15 mg/L,溶液pH值为3,活性炭投加量为0.2 g/50 mL,吸附时间为4 h,吸附温度为50℃,此条件下磁性Fe_(3)O_(4)/活性炭的回收率达90%以上,再生的Fe_(3)O_(4)/活性炭循环使用5次后仍具有较好的吸附效果。

Magnetic Fe_(3)O_(4)/activated carbon was prepared by chemical coprecipitation method.The modified activated carbon was analyzed by scanning electron microscope(SEM),fourier transform infrared spectrometer(FTIR)and X-ray diffractometer(XRD).The results showed that Fe_(3)O_(4) was successfully loaded onto the activated carbon.Fe_(3)O_(4)/activated carbon was used to adsorb Cr(Ⅵ)in simulated wastewater.The effects of initial concentration of Cr(Ⅵ),the dosage of activated carbon,adsorption time,adsorption temperature and pH value on the adsorption performance were investigated.The magnetic Fe_(3)O_(4)/activated carbon was recovered and regenerated.The results showed that the optimal adsorption conditions were Cr(Ⅵ)initial concentration of 15 mg/L,pH value of 3,activated carbon dosage of 0.004 g/mL,adsorption time of 4 h,adsorption temperature of 50℃.The recovery rate of magnetic Fe_(3)O_(4)/activated carbon is above 90%,and the regenerated Fe_(3)O_(4)/activated carbon still has good adsorption effect after recycling for 5 times.