对不同老化时间的聚氯乙烯吸附甲基橙的机理研究

Study on the Adsorption Mechanism of Methyl Orange on PVC with Different Aging Time

以聚氯乙烯(PVC)微塑料为吸附材料,以甲基橙(MO)为目标污染物,通过紫外光照对PVC进行老化,研究老化时间对PVC吸附MO的影响。采用扫描电镜、全反射红外光谱对不同老化时间的PVC微塑料进行表征,探讨老化时间对PVC微塑料表面性质的影响。结果表明:老化PVC微塑料表面产生裂纹和孔隙,使得饱和吸附量逐渐增加;同时,老化可以使PVC微塑料表面产生一定含氧基团,表面极性增加,与MO的相互作用力随之增大;当吸附MO时,随着老化时间延长,Freudlich模型的拟合度最好,表明老化PVC微塑料对于MO的吸附表现为不均匀吸附。且随着老化的进行,其饱和吸附量逐渐增加,最大为4.7 mg/g。

Using polyvinyl chloride(PVC)microplastics as the adsorption material and methyl orange(MO)as the target pollutant,the PVC was aged by ultraviolet light,and the effect of aging time on the adsorption of MO by PVC was studied.SEM and total reflection infrared spectroscopy were used to characterize PVC microplastics with different aging times,and the influence of aging time on the surface properties of PVC microplastics was discussed.The results show that:cracks and pores on the surface of aging PVC microplastics gradually increase the saturated adsorption capacity;at the same time,aging can produce certain oxygen-containing groups on the surface of PVC microplastics,the surface polarity increases,and the interaction force with MO increases accordingly.When MO is adsorbed,as the aging time is prolonged,the Freudlich model has the best fit,indicating that the adsorption of the aged PVC microplastics to MO is not uniform.And with the progress of aging,its saturated adsorption capacity gradually increased,and the maximum was 4.7 mg/g.