磷酸改性向日葵秸秆对Cr~(6+)的吸附性能

以向日葵秸秆为原料,用磷酸改性制备秸秆活性炭,研究了秸秆活性炭的投加量、pH值、吸附时间和温度等因素对水溶液中Cr6+吸附的影响。结果表明:向日葵秸秆活性炭对Cr6+有很强的吸附去除作用;在吸附震荡时间为1.5 h,温度为25℃,吸附剂的投加质量浓度为8 g/L,pH值为4—7时,向日葵秸秆活性炭对Cr6+的吸附去除率为98.9%以上;升高温度有利于吸附,Langmuir等温模型能很好地反映吸附过程特征,吸附过程符合准二级动力学方程。

Cr6+ adsorptive removal from solutions with sunflower straw-modified by phosphoric acid

With sunflower straw as raw materials,the modified straw active carbon was prepared by phosphoric acid.The influence of the dosage of straw active carbon,pH value,adsorption time,temperature,etc.on adsorption process and adsorption performance of Cr6+ onto straw active carbon were investigated.The results of this experiment show that sunflower straw has better adsorptive removal effects of Cr6+,and the optimal removal efficiency of 98.9% can be obtained after it is oscillated for 1.5 h when the temperature of Cr6+ is 25 ℃,the mass concentration of adsorbent is 8 g/L,the pH value of adjustment solution is between 4 and 7.The adsorption equilibrium fits in with the Langmuir isotherm very well;higher temperature profits this adsorption process,and the adsorption process of Cr6+ conforms to the pseudo-second-order reaction.