摘要
通过静态批处理吸附试验,研究了γ-MnO2对Tl（Ⅰ）（铊）的吸附性能,考察了溶液的pH、离子强度、γ-MnO2投加量、接触时间、初始ρ〔Tl（Ⅰ）〕和温度等因素对吸附的影响.结果表明：在pH为2-3的酸性溶液中,γ-MnO2对Tl（Ⅰ）的吸附容量随着pH的增大而减小;当pH为4-6时,吸附容量随pH的增加而迅速增大;而当pH〉6时,吸附达到平衡.γ-MnO2对Tl（Ⅰ）的吸附量随着离子强度的降低、γ-MnO2投加量的减小而增大.γ-MnO2对Tl（Ⅰ）的吸附在15min内达到平衡,并满足准二级动力学方程.在温度为288、303、318K的条件下,初始ρ〔Tl（Ⅰ）〕为10-1000mg/L时,最大饱和吸附量分别为53.04、49.05、45.03mg/g,符合Freundlich吸附等温方程.γ-MnO2对Tl（Ⅰ）的吸附过程是自发的放热过程.脱附研究表明,γ-MnO2表面的吸附行为属离子交换,并受离子强度影响.试验证明,γ-MnO2是一种极具潜力的Tl（Ⅰ）吸附剂.
Static batch experiments were performed to evaluate the combined effects of pH, ionic strength, γ-MnO2 dosage, contact time, TI（ Ⅰ ） initial concentration and temperature on TI（ Ⅰ ） sorption toward γ-MnO2. The adsorption of TI（Ⅰ ） on γ-MnO2 is pH-dependent; it dropped significantly with pH rise from 2 to 3, was followed by rapid promotion with further increased pH from 4-6, and finally attained equilibrium with pH 〉6. The adsorption of TI（ Ⅰ ） on y-MnO2 was strongly affected by changes in ionic strength and γ-MnO2 dosage, increasing with the decrease of the ionic strength and the sorbent dosage. The experimental data of Tl（ Ⅰ ） adsorption on γ-MnO2 reached equilibrium within 15 minutes and were fitted well by the pseudo-second-order model. Moreover, when initial concentrations of Tl（ Ⅰ ） ranged from 10 to 1000 mg/L, under temperatures of 288, 303 and 318 K, the adsorptions were fitted well by the Freundlich isotherm,and the maximum adsorption capacities of γ-MnO2 for Tl （Ⅰ ） were up to 53.04, 49.05 and 45.03 mg/g, respectively. The adsorption of Tl （Ⅰ ） on γ-MnO2 was essentially an exothermic and spontaneous process. Studies of desorption showed that the adsorption behavior of γ-MnO2 surface is ionic exchange, which is affected by the ionic strength. The results indicated that γ-MnO2could be a promising adsorbent for Tl（ Ⅰ ） in water environments.
出处
《环境科学研究》
EI
CAS
CSSCI
CSCD
北大核心
2015年第1期103-109,共7页
Research of Environmental Sciences
基金
国家自然科学基金项目(41170399)
广东省环境污染控制与修复技术重点实验室(中山大学)基金项目(2013K0010)
