摘要
以宝钢电炉钢渣为研究对象,考察了钢渣对溶液中重金属离子Cu2+、Cd2+、Pb2+的吸附动力学、吸附等温线、吸附热力学特征,借助多种分析手段(XRD、BET比表面分析、SEM/EDS等)对钢渣进行了理化性能测试和表征.结果表明,电炉钢渣对重金属离子的吸附速率较快,吸附速率顺序为Cd2+>Pb2+>Cu2+,吸附过程符合一级动力学模型(R2>0.99).吸附等温实验结果表明,Langmuir模型较为适合重金属离子在钢渣上的吸附,实验条件下对Cu2+、Cd2+、Pb2+离子的最大吸附容量分别为0.101、0.058、0.120 mmol.g-1.3种重金属离子在钢渣上的吸附是一个吸热(ΔH0<0)、熵值增大(ΔS0>0)的自发反应过程(ΔG0<0),熵效应是吸附反应自发进行的主要驱动力.SEM/EDS分析结果揭示了吸附前后钢渣表面形貌和化学成分的变化.电炉钢渣以其低价、高效性在重金属废水处理中具有广阔的应用前景.
Batch experiments were carried out to investigate the adsorption kinetics and thermodynamic characteristics of heavy metal ions Cu2＋,Cd^2＋ and Pb^2＋ on the electric arc furnace（EAF） slag from Baoshan Steel Factory.Several kinds of techniques including XRD analysis、BET specific surface analysis and SEM/EDS analysis were employed to determine the physico-chemical and surface characteristics of slag.Results indicated that the adsorption rate of heavy metal ions on the EAF slag was relatively high,and the sorption rate followed the order Cd^2＋〉Pb^2＋〉Cu2＋.The adsorption kinetics obeyed first-order kinetics model（R2〉0.99）.Adsorption isotherm experiment showed that adsorption isotherm of heavy metal ions on slag fitted Langmuir model,and the maximum adsorption capacity of Cu2＋,Cd^2＋ and Pb^2＋ was 0.101,0.058 and 0.120 （mmol·g-1）,respectively.The adsorption of heavy metal ions on slag was a spontaneous reaction（ΔG^0〈0） with endotherm（ΔH^0〈0） and the increase of enthopy（ΔS^0〉0）.The effect of enthopy was the main driving force of the spontaneous adsorption reaction.The analysis results of SEM/EDS revealed the changes of surface morphology and chemical proportion before and after adsorption.Due to low-cost and high-efficiency,electric arc furnace slag showed great potential for the treatment of heavy metal polluted wastewaters
出处
《环境科学》
EI
CAS
CSCD
北大核心
2009年第10期2940-2945,共6页
Environmental Science
基金
科技部国际科技合作项目(2005DFA90960)
关键词
钢渣
重金属
吸附动力学
吸附等温线
热力学
slag
heavy metal
adsorption kinetics
adsorption isotherm
thermodynamic study
