Adsorption properties of different forms of polyethylene microplastics on Fe3+
To explore the influence of different forms of polyethylene(PE)microplastic on the adsorption performance of Fe3+,and the interaction between PE with Fe3+,low-density polyethylene(LDPE)and linear low-density polyethylene(LLDPE)were chosen to represent different forms of PE in this investigation.The structures and morphologies were characterized by SEM,FTIR,Brunauer-Emmett-Teller method and Zeta potential,and the impact of various forms of PE on the adsorption of Fe3+was systematically examined through static adsorption experiments.The results indicated that LDPE was better than LLDPE in particle dispersion,specific surface area,and surface negativity,with a maximum adsorption capacity for Fe3+of 5.01 mg·L-1.The adsorption capacity of PE for Fe3+increased first and then decreased with the increase of microplastic dosage,the temperature rise was beneficial to the adsorption reaction.The adsorption of Fe3+by LDPE and LLDPE was consistent with the pseudo-first-order kinetics and Langmuir model,indicating that single-layer physical adsorption was the dominant mechanism.The particle diffusion model revealed that the adsorption process was predominantly governed by surface adsorption,and internal diffusion was not the only controlling step of the adsorption rate.In addition,diffusion force and electrostatic force were the primary mechanisms of Fe3+adsorption by LDPE and LLDPE,and the mechanism was not affected by linear structure.
万方数据
