Simultaneous Cd2+ and organic matter sorption behavior on various microplastics: Modeling of influencing factors using the Taguchi method

Abstract

In aquatic environments, microplastics (MPs) can serve as a vector for pollutants. Pollutants adsorbed on the surface of microplastics pose a potential risk to aquatic organisms. In this study, the effect of environmental conditions such as duration, pH and conductivity on the Cd+2 and organic matter adsorption capacity, qe,Cd and qe,COD of microplastic type was evaluated using the Taguchi experimental design method. ANOVA results showed that the most effective factor in adsorption capacity was the microplastic type. qe,Cd were listed as > 0.6–0.8 mg/gPP, >0.4 mg/gMDPE, 0.2 mg/gLDPE at 50 mS/cm. It was observed that conductivity had a positive effect on qe,Cd.,qe,Cd for PP in waters with conductivities of 50 mS/cm, 0.8 mS/cm, 0.02 mS/cm at pH 7.0 was found to be ≫ 0.6, >0.2, > 0.4, respectively. qe,Cd and qe,COD showed similar trends. It was determined that the qe,COD at 50 mS/cm was in the order of 15–22 mg COD/gPP, 5–10 mg COD/gMDPE, but not determined for LDPE. After MW and UV artificial aging, qe,COD of virgin PP increased by 31.5 % and 94.4 %, respectively, whereas the qe,Cd decreased by 1.2 % and 24 %.