摘要
以莲子壳为吸附剂,考察了初始pH值、莲子壳用量、温度和吸附时间等因素对水中Cr(III)去除效果的影响,并对吸附等温过程和吸附动力学进行了数学模型拟合。结果表明:在溶液初始pH值为4.0、莲子壳投加量为8.00g/L、温度为30℃、吸附时间为24h的条件下,Cr(III)的去除率可达96.64%;莲子壳对Cr(III)的吸附过程符合准二级动力学方程,其等温吸附规律可用Langmuir模型进行描述,Langmuir模型得出的理论最大吸附容量为20.08mg/g,与试验得到的最大吸附容量21.95mg/g接近;通过吸附热力学计算得出莲子壳对Cr(III)的吸附是自发的吸热过程;结合FTIR和SEM谱图分析,推断莲子壳对Cr(III)的吸附主要为包含氧化还原反应的复杂的物理化学过程。
This paper uses lotus seed shell as biosorbent to remove Cr（III）from aqueous solution,discusses the adsorption performance of lotus seed shell on Cr（III）and investigates the influences of solution pH,dose of adsorbent,agitating time,metal concentration and temperature on the removal rate of Cr（III）,and models adsorption isothermal process and adsorption kinetics/thermodynamic.The result indicates that when adsorption temperature is 30℃,pH value of initial adsorption solution is 4.0,dosage of lotus seed shell is 8.00g/L and adsorption time is 24 h,the removal efficiency of Cr（III）is up to 96.64%.The adsorption process of lotus seed shell on Cr（III）can be described by the second kinetic equation,and the isothermal adsorption behavior of lotus seed shell on Cr（III）can be described by Langmuir equation.Langmuir isotherm suggests that the optimal adsorption capacity is 20.08mg/g,close to the experimental result of 21.95mg/g.Thermodynamic analysis reveals that the adsorption process is a spontaneous endothermic.Finally,FTIR and SEM imagines indicate that the process of Cr（III）adsorption by lotus seed shell coexists with redox process.
出处
《安全与环境工程》
CAS
北大核心
2014年第6期98-103,共6页
Safety and Environmental Engineering
基金
广西自然科学基金项目(2011GXNSFA018007)
广西科学研究与技术开发计划应用基础研究专项项目(桂科攻1140002-3-2)
广西教育厅资助项目(201012MS097)
