甘蔗渣炭对废水中Cr(Ⅵ)的吸附

摘要

Sugarcane bagasse is used as raw material to carbonize bagasse in a vacuum atmosphere.The bagasse carbonized before and after carbonization was characterized by SEM, FTIR and BET.The adsorption effect of bagasse carbon on Cr (Ⅵ) in wastewater was studied.The results show that the pore structure of bagasse before charring is relatively small and the structure is relatively smooth.After coking, a large number of pores appear in the bagasse and the specific surface area increases greatly.And the carbonized bagasse chemical structure has changed, resulting in new functional groups, the adsorption effect is greatly enhanced.The optimum conditions for the adsorption of Cr (Ⅵ) in waste water were as follows:the adsorption temperature was 25℃, the initial wastewater p H was 1, the amount of bagasse was carbonized 14 g/L, the adsorption time was 120 min, 120 r/min.When the wastewater with the initial concentration of 50 mg/L was treated under this condition, the removal rate reached 94.5％and the maximum adsorption capacity was 4.805 mg/g.The results show that the Langmuir isothermal adsorption model can better reflect the adsorption process.Adsorption kinetics results show that the adsorption process follows the pseudo-second-order kinetic equation.%以甘蔗渣为原料,在真空氛围下炭化,制得甘蔗渣炭.采用SEM、FTIR、BET等方法对炭化前后的甘蔗渣进行表征,研究了甘蔗渣炭对废水中Cr(Ⅵ)的吸附效果.结果显示,炭化前甘蔗渣孔结构较少,结构较平整;炭化后甘蔗渣出现大量孔隙,比表面积大大增加.甘蔗渣化学结构发生了变化,产生新的官能团,吸附效果大大提高.炭化甘蔗渣吸附废水中Cr(Ⅵ)的最佳工艺条件为:吸附温度25℃,初始废水p H=1,炭化后甘蔗渣加入量14 g/L,吸附时间120 min,转速120 r/min.在此条件下处理初始浓度50 mg/L的废水时,去除率达到94.5％,最大吸附量4.805 mg/g.Langmuir等温吸附模型、拟二级动力学方程能更好的反应吸附过程.