【摘要】 利用合成的非晶态磷酸锡作为吸附剂,研究了多种因素(pH、吸附时间、初始浓度、温度、离子强度)对吸附剂吸附水溶液中Cu2+的影响。结果表明,非晶态磷酸锡对Cu2+的吸附量随着pH(3.00～6.50)的增大、吸附时间的延长而增加。用Freundli-ch、Langmuir方程对等温吸附数据进行处理,Langmuir方程拟合效果更好,293K时饱和吸附量达到238.10mg/g。Dubinin-Ra-dushkevich方程的吸附能(Es)介于4.44～10.33kJ/mol,表明吸附过程是化学离子交换,吸附机制为非晶态磷酸锡中的H+与溶液中的Cu2+发生离子交换反应。吸附过程的热力学研究表明,非晶态磷酸锡对Cu2+的吸附是一个自发的、吸热的过程,升温有利于吸附。离子强度实验结果表明,高盐强度对非晶态磷酸锡吸附Cu2+有一定的不利影响,但影响幅度不大,可以用于去除养殖海水中的Cu2+。所吸附的Cu2+可以用HCl解吸,说明非晶态磷酸锡具有重复利用的潜能。更多还原

【Abstract】 The batch removal of Cu2+ from aqueous solutions by adsorption of amorphous tin(Ⅳ) phosphate adsorbent was investigated to determine the effect of pH,contact time,adsorbate concentration,reaction temperature and ionic strength on the adsorptive capacity for Cu2+.Experimental results showed that the adsorption quantity increased with increasing of solution pH(3.00-6.50) and reaction time.The equilibrium data were analyzed by the Freundlich and Langmuir isotherm models.The results showed that the sorption process followed Langmuir model well.The maximum sorption capacity amounted to 238.10 mg/g at 293 K.The free energy Es(4.44-10.33 kJ/mol) got from the Dubinin-Radushkevich isotherm also indicated the sorption process was a chemical ion-exchange mechanism.The sorption mechanism of the process was the ion-exchange reaction between Cu2+ and H+.The negative ΔG0 values and the positive ΔH0 and ΔS0 at various temperatures confirmed the adsorption processes were spontaneous and endothermic.Ionic strength experiments showed that it was feasible for amorphous tin(Ⅳ) phosphate in removing Cu2+ from hypersaline media,such as marine culture wastewater.Desorption experiment in the media of HCl solution indicated the adsorbent can be reused,which enhanced its value in practical application.更多还原