Two Dimensional MOF Encapsulating Magnetic Char Beads for Removal of Microplastic and Dissolved Arsenic From Aqueous System

ABSTRACT Microsized polystyrene (PS, <5 µm) acts as a carrier of toxic metals, like arsenic (As), and poses a serious threat. The complicated surface chemistry of the micro PS+As contaminants makes it challenging to remove. Herein, we report a versatile adsorbent, KOH‐activated magnetic carbon and metal‐organic framework hybrid material (MCK6@MOF) for the removal of micro PS+As contaminants from aqueous systems. The hybrid MCK6@MOF, synthesized through a room‐temperature approach tailored with diverse functionalities, adsorbs PS+As toxic contaminants with ∼100% efficiency within 15 min at ambient conditions. The presence of As with PS alters its surface charge and accelerates adsorption, reducing the adsorption time for the PS+As by four times. Adsorption studies for complex‐contaminated systems demonstrate that the presence of metals (As(III), Cr(III), Cu(II)) in an aqueous environment with PS microplastics alters the surface charge of the adsorbent, resulting in 98% adsorption of PS within 15 min. Ex situ analysis confirms that electrostatic attraction, π‐π interaction, hydrogen bonding and surface complexation are the driving adsorption mechanisms. MCK6@MOF retains removal efficiency of 96% for the PS+As complex over multiple cycles. The regeneration process resulted in ∼10% mass loss of the adsorbent, indicating partial deterioration of the material structure.