摘要
以焦锑酸钾(KSb(OH)6)为Sb(V)锑源,采用XRD,XRF,FTIR对蛇纹石进行表征。探讨了不同吸附时间、Sb(V)初始浓度、初始pH、温度条件下蛇纹石吸附除Sb(V)的效果。结果表明:在动力吸附模型中,Elovich模型和假二级动力学模型对蛇纹石处理Sb(V)的拟合效果均较好,吸附过程为由化学吸附控制的非均相扩散,由假二级动力学模型可知理论最大吸附量为2.82×10-3;在等温吸附模型中,Langmuir模型拟合效果稍优于Freundlich模型,理论最大吸附量可达8.90×10-3;在广泛pH范围内,吸附量随着初始pH的降低而增加,初始pH值在1.9~3.6范围内时,吸附量迅速从6.66×10-3减少至2.97×10-3,初始pH值大于3.6,吸附量随pH值增加而减少的幅度变小;蛇纹石对Sb(V)的吸附去除量随温度的升高而增大,最大为5.25×10-3。蛇纹石Sb(V)的吸附为化学吸附;高零电点使蛇纹石在广泛pH值范围内可被质子化,Sb(OH6)-与质子化的镁氧(氢氧)八面体端面形成配合物。
KSb(OH)6 was selected as Sb(V) antimony source to characterize the natural serpentine by means of XRD,XRF and FTIR.The effect of adsorption on Sb(V) at different adsorption time,initial concentration of Sb(V),initial pH and temperature was discussed and the adsorption and removal effect of natural serpentine on Sb(V) was studied. It shows that,in the kinetic adsorption model,the Elovich model and pseudo-second dynamic model had a better fitting effect of adsorption and removal of natural serpentine on Sb(V).The adsorption process was heterogeneous diffusion controlled by chemical adsorption and the theoretical maximum adsorption of pseudo-second dynamic model was 2.82×10-3.In the isothermal adsorption model,the fitting effect of Langmuir model with a theoretical maximum adsorption capacity of 8.9×10-3 was a bit better than that of Freundich model. It was revealed that the adsorption capacity increased with the decrease of initial pH in a wide range and adsorption capacity dropped slowly from 6.66 to 2.97×10-3 when pH value ranged from 1.9 to 3.6.The adsorption capacity of natural serpentine on Sb(V) increased up to 5.25×10-3 when temperature rised.The study proved that the adsorption process was chemical one. Natural serpentine was protonated at high point of zero charge(PZC) in a wide range of pH and the Sb(OH6)-formed a complex with protonated Mg-O(H-O) octahedral face.
作者
肖中亿
刘爱平
龙智贤
冯钰淞
林胜
Xiao Zhongyi;Liu Aiping;Long Zhixian;Feng Yusong;Lin Sheng(College of Environment of Resources,Southwest University of Science and Technology,Mianyang,Sichuan 621010,China)
出处
《矿物岩石》
CAS
CSCD
北大核心
2019年第4期1-5,共5页
Mineralogy and Petrology
基金
四川省教育厅项目(12zd1121)
西南科技大学大学生创新基金精准资助项目(JZ19-029)
关键词
蛇纹石
Sb(V)
吸附量
质子化
serpentine
Sb(V)
adsorption capacity
protonation
