Removal of Polystyrene Microplastics from Aqueous Solution Using the Metal–Organic Framework Material of ZIF-67

Abstract

Due to the continuous and adverse effects of microplastics on the environment, an increasing number of studies have begun to focus on their migration patterns and removal from aquatic environments. Herein, our study innovatively evaluated the ability of the capacity of ZIF-67, a novel metal–organic framework (MOF) material, to adsorb polystyrene (PS) microplastics (MPs) from aqueous solutions, aiming to explore the potential of MOF materials to remove MPs from wastewater. The adsorption ratio of PSMPs (5 mg/L, 30 mL) by ZIF-67 reached up to 92.1%, and the PSMP adsorption equilibrium was achieved within 20 min at 298 K. The adsorption of PSMPs would be favored at a pH of 8, a PSMPs solution concentration of 5 mg/L, and a temperature of 298 K. Further analyses demonstrated that hydrogen bond interactions, π-π stacking, and electrostatic interactions played a crucial role in the adsorption of PSMPs by ZIF-67 in aqueous solutions. Our findings thus provide insight into novel methods to remove MPs from acidic and weakly alkaline aquatic environments and wastewater.

Nanoplastics Removal from Water using Metal–Organic Framework: Investigation of Adsorption Mechanisms, Kinetics, and Effective Environmental Parameters

“…Metal–organic frameworks (MOFs) are porous, crystalline materials constructed by the assembly of metal ions and organic ligands, which showed great performance in various applications like gas storage, separation, catalysis, sensing and contaminant removal, etc. − Owing to the high porosity, tunable structure, and rich functionality, MOFs show promising properties such as structural and surface tunability as a potential adsorbent for nanoplastics removal from water. − Previous research has demonstrated the use of Zr-based-MOFs (UiO-66-OH@MF-3) and Co-based-MOFs (ZIF-67) for the removal of micro-/nanoplastics. However, these MOFs showed limited adsorption capacity (about 34.5 mg/g) toward micro-/nanoplastics. , …”

“…However, these MOFs showed limited adsorption capacity (about 34.5 mg/g) toward micro-/nanoplastics. 42,43 Hence, we report using Cr-based-MOFs for efficient removal of polystyrene nanoplastics (PSNPs) from water with enhanced adsorption capacity. We report complete isotherm adsorption experiments, including equilibrium study and kinetic study, at different concentrations of PSNPs and varying operating conditions.…”

Metal-organic frameworks and plastic: an emerging synergic partnership

“…In a recent research, ZIF-67 was investigated as a viable adsorbent material for MPs from water media [ 56 ]. PS MPs with particle dimensions falling in the range of 1.0–3.0 µm were used for simulating MPs waste and their interactions with ZIF-67 particles were studied at a 3–10 pH range and at different temperatures (288–308 K).…”

“… Entry MOF or MOF-based composite MPs/NPs Application Conditions Process efficiency Ref. 1 ZIF-67 PS (1–3 µm) Adsorbent 5 ppb of MPs in water at a 3–12 pH range, 288–308 K Up to 92.1% of removal at 298 K [ 56 ] 2 MIL-101(Cr) PS (65 nm) Adsorbent 5–100 ppm of NPs in MiliQ water at pH 5–10, 25°C Up to 96% of removal at 5 and 70 ppm, pH 5 [ 57 ] 3 UiO-66-X in a melamine porous foam, X = H, NH 2 , OH, Br and NO 2 PVDF 260–322 nm PMMA 325 nm PS 183 nm Adsorbent 0.5–2 ppm of MPs in water/ethanol (3:1) or simulated seawater environments PMMA, 88.2% PS 85.7% PVDF Up to 95.5% of removal [ 58 ] 4 ZIF-8 in a wood aerogel PVDF (60—110 nm) PS (90―140 nm) Adsorbent 0.5 ppm of MPs in water/ethanol (3:1) and seawater environments Up to 91.4% of removal [ 59 ] 5 PSF/MIL-100 (Fe) mixed matrix membrane PVC (134.6 µm) PE (42.5 µm) Adsorbent Different concentrations of MPs/Nps in water at different pHand in presence of MB Up to 99% of removal [ 60 ] 6 UiO-66(Zr) PET chips Catalytic degradation Solvent-free p...…”

New Technologies to Decontaminate Pollutants in Water: A Report about the State of the Art

“…The main driving forces of this adsorption are hydrogen bonds, stacking and electrostatic interactions. These findings represent a step forward in the field of removing micro-plastics with innovative and eco-sustainable materials [ 20 ]. In the experimental report by P. Guidi et al they have described and studied experimentally, the damage that spills of petroleum and derived oils in water can create on the environment and in particular on living organisms.…”