摘要
应用批量平衡法,以膨润土、硅藻土和氧化镁为原料,探索了组配固化剂对Pb^(2+)的吸附性能、作用机制及影响因素,为将天然材料固化剂应用于重金属污染土壤修复提供理论参考。结果表明,组配固化剂对Pb2+的吸附行为符合二级动力学模型,等温吸附曲线符合Langmuir方程,吸附过程是自发、吸热反应,以物理吸附为主,30、40和50℃的最大吸附量分别为96.2、114.9和151.5 mg·g^(-1)。吸附过程受pH值和盐度的影响,膨润土、硅藻土与氧化镁混合,能有效提高对Pb^(2+)的吸附固化效果。
A magnesia-based curing agent was prepared using bentonite,diatomite,and magnesia with the help of the batch equilibrium method. Pb^(2+) adsorption and its influential factors on securing a matching curing agent in aqueous solution were investigated. The sorption kinetic processes followed a pseudo-second-order kinetic model,as the isothermal data more closely followed a Langmuir model than a Freundlich or Tempkin model. The maximum Pb^(2+) adsorption capacity to matching curing agent of 96. 2,114. 9,and 151. 5 mg·g^(-1)was observed at30,40 and 50 ℃,respectively. The apparent thermodynamic parameters( ΔG^0,ΔH^0,and ΔS^0) indicated that the adsorption process was spontaneous,endothermic,and entropically unfavorable toward physisorption. The pH and calcium ion strength affected the adsorption,indicating that bentonite and diatomite promoted the adsorption effect of magnesia.
出处
《环境工程学报》
CAS
CSCD
北大核心
2016年第7期3859-3865,共7页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(41371317)
广东省普通高校特色创新项目(2014KTSCX056)
广州市产学研协同创新重大专项(201604020077)
关键词
氧化镁
组配固化剂
铅
吸附
magnesia
matching curing agent
lead
adsorption