二氧化硅/聚噻吩复合吸附剂处理Pb2+和Cd2+

绿色环保、高效等特点是吸附剂发展的趋势。以溶胶-溶剂热法合成了SiO₂,再与聚噻吩反应合成了SiO₂/聚噻吩复合材料。采用扫描电镜(SEM)、傅里叶红外光谱(FT-IR)以及Zeta电位对复合材料进行了表征分析。SiO₂/聚噻吩是表面粗糙的球形,且表面带有负电荷。SiO₂/聚噻吩复合材料用于吸附Pb²⁺和Cd²⁺离子,改变吸附过程中的变量来研究吸附过程的影响因素,通过探讨动力学和等温线模型来研究其吸附机理。研究结果表明,pH通过改变SiO₂/聚噻吩表面的电荷数来影响吸附性能,吸附容量与吸附剂的量不呈正相关。同时得知,SiO₂/聚噻吩吸附剂吸附Pb²⁺和Cd²⁺的过程符合拟二级动力学模型及Langmuir等温线模型。根据研究结果提出吸附机理:SiO₂/聚噻吩表面的负电荷吸引带有正电荷的重金属离子,以单分层的化学吸附为主吸附过程。

Treatment of Pb2+ and Cd2+ with Silica/Polythiophene Composite Adsorbent

Development of adsorbents is required to meet green environmental protection and high efficiency.This contribution reports SiO₂/polythiophene is composites which were synthesized by sol-solvothermal method using SiO₂ and polythiophene,and characterization results by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR)and Zeta potential illustrate the composites to be spherical with surface rough and negatively charged.The composite are used to adsorb Pb and Cd ions,and the factors influencing the adsorption process are studied,and the adsorption mechanism is studied by discussing the kinetics and isotherm model.The results show that pH affects the adsorption performance by changing the charge number of SiO₂/polythiophene surface,and the adsorption capacity is un-correlated with the amount of adsorbent.It is also found that the adsorption process of Pb and Cd on SiO₂/polythiophene is adsorbent conforms to the pseudo second-order kinetic model and Langmuir isotherm model.Consequently,the adsorption mechanism is proposed:the negative charge on the SiO₂/polythiophene surface attracts the positively charged heavy metal ions,and the single layered chemical adsorption is the main adsorption process.