0
Article Tier 2 Nanoplastics Remediation Sign in to save

Enhanced flotation removal of polystyrene nanoplastics by chitosan modification: Performance and mechanism

The Science of The Total Environment 2024 17 citations

AI summary Read the abstract

Researchers improved removal of polystyrene nanoplastics from water using chitosan-modified air flotation, boosting removal efficiency from 3.1% to 96.7% by exploiting electrostatic attraction, enhanced hydrophobicity, and bridging adsorption to cause nanoplastics to aggregate into large, buoyant flocs.

Polymers

Nanoplastics are difficult to remove from water using conventional flotation processes due to their stability and resistance to biodegradation. Here, polystyrene nanoplastics (PSNPs) were selected as the object of study. In addition, chitosan (CTS), an environmentally friendly natural cationic polymer, was selected to modify the air flotation process to improve the separation of PSNPs using air flotation. Adding chitosan effectively enhanced the removal of PSNPs using air flotation from 3.1 % to 96.7 %. The residual concentration decreased from 9.69 mg/L to 0.33 mg/L. Removal of PSNPs by CTS-modified air flotation was maintained at 92.8 % even when the air flotation time was significantly shortened. The zeta potential alterations demonstrated robust electrostatic attraction within the CTS-modified air flotation process. The contact angle measurements indicated that incorporating CTS could enhance the hydrophobic interaction between bubbles and PSNPs. PSNPs particles around 100 nm agglomerated to form floating flocs with a particle size of more than 4500 nm. Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) images confirmed the presence of tight adhesion between PSNPs and CTS, indicating the presence of bridging adsorption during the process. The major PSNPs removal mechanisms included electrostatic attraction, enhancement of hydrophobicity, and bridging adsorption. Increasing the aeration volume could improve the removal rate, but this improvement was finite. Weakly acidic and low ionic strength conditions favored PSNPs removal. The CTS-modified air flotation process showed great potential for PSNPs removal from real water bodies.

More Papers Like This

Article Tier 2

Improving nanoplastic removal by coagulation: Impact mechanism of particle size and water chemical conditions

AI summary Read the abstract

Researchers found that coagulation using aluminum chlorohydrate and polyacrylamide achieved up to 98.5% removal efficiency for polystyrene nanoplastics, with smaller particles being easier to remove, though humic acid in water competed for adsorption sites and reduced effectiveness.

Article Tier 2

Exploration of interaction mechanism and removal performance of polystyrene nanoplastics with covalent organic framework: Experimental and theoretical study

AI summary Read the abstract

Researchers synthesized a covalent organic framework (COF) material and demonstrated it can remove polystyrene nanoplastics from water with 99% efficiency within two hours, driven primarily by electrostatic attraction, and retains strong performance across multiple regeneration cycles.

Article Tier 2

Integrated Chitosan-based coagulation and microbubble pre-treatment for improved microplastic fibre removal from water

AI summary Read the abstract

Researchers developed a combined chitosan-based coagulation and microbubble pre-treatment system for removing microplastic fibres from water, finding that this approach overcame the limitations of conventional inorganic coagulants and improved removal efficiency for the morphologically challenging fibre fraction.

Article Tier 2

The removal efficiency and mechanism of microplastic enhancement by positive modification dissolved air flotation

AI summary Read the abstract

Researchers enhanced dissolved air flotation by modifying the process with positively charged surfaces to improve microplastic removal from freshwater, finding that the modified approach significantly outperformed conventional dissolved air flotation across three common polymer types.

Article Tier 2

Is froth flotation a potential scheme for microplastics removal? Analysis on flotation kinetics and surface characteristics

AI summary Read the abstract

This study evaluated froth flotation as a method for removing microplastics from water, finding that surface hydrophobicity governs flotation efficiency and that the technique shows promise as a scalable treatment option for certain polymer types.

Research digests by email

When a large batch of papers lands in the Atlas, we read through it and send a short write-up of what stood out.

Email me about

Share this paper