摘要
以磷酸锡晶体作为吸附剂,应用批量吸附法,研究了pH值、吸附时间、初始浓度、温度、离子强度等因素对去除水溶液中Cu2+的影响,通过热力学分析及电位滴定实验探讨了吸附机理.结果表明:磷酸锡对Cu2+的吸附量随着pH(3～6.5)以及吸附时间的增加而增大,吸附动力学过程符合准二级动力学模型.等温吸附数据用Langmuir方程拟合效果最好,20℃时饱和吸附量达到48.69mg/g.根据吸附自由能Es(kJ/mol)可知,吸附机理属于化学离子交换,即磷酸锡中的H+与溶液中的Cu2+发生了离子交换反应.该反应是一个自发的、吸热的过程,升温有利于吸附.在模拟海水中,高盐强度对磷酸锡吸附Cu2+有一定的不利影响,但幅度不大.当NaCl浓度达到0.6mol/L时,吸附量为21.87mg/g,是淡水介质时的93.3%,表明磷酸锡适用于去除养殖海水中的Cu2+.
Tin acid phosphate （SnP） was used as adsorbent for the removal of Cu（ Ⅱ ） from a- queous solutions..The extent of adsorption was investigated as a function of pH, contact time, adsorbate concentration, reaction temperature with batch experiments. Adsorption mechanism was probed by thermodynamics analysis and potentiometric titration. The results show that the amount of adsorbed copper ions increases with the increase of solution pH in the examined range （3-6.5） and reaction time. The sorption process follows pseudo-second-order kinetics very well. The equilibrium data fits better to the Langmuir isotherm equation. The maximum sorption capacity amounts to 48. 69 mg/g at 20 ℃. The free energy E^（kJ/mol） got from the D- R isotherm indicates the sorption process is a chemical ion-exchange mechanism. The ion-ex- change reaction happens between Cuz＋ and H＋ , which is spontaneous and endothermic. Ad- sorption experiments conducted in stimulated seawater find satisfactory adsorption capacity, 21.87 mg/g, at the NaC1 concentration of 0.6 tool/L, which amounts to 93.3% of the counter- part at fresh water media. So it is feasible for tin acid phosphate in removin Cu2＋ from hvt）er-saline media.
出处
《中国矿业大学学报》
EI
CAS
CSCD
北大核心
2012年第2期320-326,共7页
Journal of China University of Mining & Technology
基金
江苏省普通高校研究生科研创新计划项目(CX10B-158Z)
江苏省海洋资源开发研究院科技开放基金项目(JSIMR09D03)
淮海工学院自然科学基金项目(Z2009017)
关键词
磷酸锡
高盐废水
铜
离子交换
tin acid phosphate
high-salt wastewater
copper
ion exchange
