磁性复合有机海泡石吸附双酚A特性及动力学

通过对天然海泡石进行磁改性与有机改性,制得新型水质净化功能材料——磁性复合有机海泡石(MCOS),采用振动样品磁强计对其进行了表征,考察了其在不同pH、投加量、初始浓度、时间和温度下对水中双酚A(BPA)的吸附效果,并研究了其对BPA的吸附动力学。结果表明:MCOS具有超顺磁性,饱和磁化率为14.1 emu·g-1;MCOS对BPA的最佳吸附pH为10.0;当BPA的初始浓度为30 mg·L-1时,MCOS的适宜投加量为1.0 g·L-1;MCOS对BPA的平衡吸附时间为90 min;随着反应温度的升高,MCOS对BPA的吸附量减小。准二级反应动力学模型可以很好地描述MCOS对BPA的吸附动力学行为。颗粒内扩散模型表明,在BPA的吸附初始阶段发生了颗粒内扩散。吸附活化能为11.7 kJ·mol-1,表明吸附过程可能由化学吸附控制。

Adsorption features and kinetics of bisphenol A onto magnetic composite organic sepiolite

Magnetic composite organic sepiolite(MCOS),a novel wastewater purifying functional material,was prepared by modifying natural sepiolite using magnetic and organic treatments.MCOS was characterized using a vibrating sample magnetometer(VSM) and adsorption kinetics experiments were performed under varying temperatures.Batch experiments were conducted to investigate the impact of the initial pH,MCOS dosage,initial bisphenol A(BPA) concentration,contact time,and temperature on the adsorption features of BPA onto MCOS.The results indicated an apparent superparamagnetism in MCOS with a saturation magnetization of 14.1 emu·g-1 and an optimal pH of 10.0 for BPA removal.An initial concentration of 30 mg·L-1 BPA required a dosage of 1.0 g·L-1 MCOS,and adsorption equilibrium was observed after 90 min.The amount of adsorption decreased with increasing temperature,and a pseudo-second order model properly depicted the adsorption kinetics analysis.The intraparticle diffusion model suggested that BPA transferred to MCOS by intraparticle diffusion at the onset of adsorption.The activation energy of adsorption was 11.7 kJ·mol-1,which indicated that the adsorption process was mainly chemically controlled.