BIO-AGING OF POLYETHYLENE AND ITS IMPACT ON SORPTION OF ORGANICS

Date

2024-7-26

Author

DASSOUKI DIT TAHAN, MAHA

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

85
views

20
downloads

Cite This

Microplastics (MPs) are a global threat due to their ubiquitous presence and potential risks to food chain through interactions with organic contaminants (OCs). Additionally, MPs undergo aging in the environment, affecting their interaction with OCs. While UV-aging has been extensively studied, bio-aging of MPs remains underexplored. This study aims to comparatively evaluate sorption of two OCs namely, triclosan (TCS) and trichlorophenol (TCP) on pristine and bio-aged high-density polyethylene (HDPE) and low-density polyethylene (LDPE). Anaerobic and aerobic reactors containing PE were operated under mesophilic conditions to induce bio-aging on MPs, sorption experiments were then conducted with selected OCs. Results indicate that, during bio-aging, high doses of HDPE inhibit methane production, whereas LDPE induces no inhibition. This was attributed to the presence of additives in HDPE. Characterization studies revealed no change in carbonyl index (CI) for bio-aged HDPE, while CI increased for aerobic and anaerobic aged LDPE, indicating structural changes. Surface alterations, including rougher textures and minor changes in crystallinity, were observed in bio-aged MPs. Sorption results varied among OCs: (i) TCS consistently had higher sorption affinity than TCP, (ii) TCP had no affinity for anaerobically aged HDPE or LDPE, whereas sorption was favorable for aerobically aged LDPE (iii) TCS sorption capacities were similar for pristine and aerobically-aged, but lower for anaerobically-aged LDPE. Overall, there are complex interactions between MPs and microorganisms in digesters, where HDPE and LDPE do not affect and are not affected by them equally. Bio-aged PE in turn exhibits a variety of sorption affinities towards OCs tested.

Subject Keywords

Polyethylene, Bio-aging, Anaerobic Digestion, Aerobic Digestion, Organic Contaminants

URI

https://hdl.handle.net/11511/110908

Collections

Graduate School of Natural and Applied Sciences, Thesis