Bioremediation of Trifluralin via macroplastics in freshwater ecosystems compared to soil ecosystems

Abstract

Bioremediation is the process of environmental detoxification of toxic contaminants. Plastic is capable of the sorption of toxic chemicals and microplastics are capable of adsorbing to the surfaces of macrophytes within the water column. There is a lack of mitigation studies focusing on microplastics and sorbed contaminants within a freshwater context. Here, the aim was to quantify whether there is potential for bioremediation technologies to be implemented using Lemna minor and the plastic mulch films LDPE and PLA-PBAT to degrade the herbicide trifluralin.¹⁴C-labelled trifluralin solutions of varying concentrations (1, 10 and 100%) were created and applied to LDPE and PLA-PBAT plastic mulch films to calculate sorption potential. Bioremediation of ¹⁴C-trifluralin at these concentrations were tested via LDPE and PLA-PBAT within soil and within freshwater (100% concentration only) using Lemna minor and river sediment. Measurements were undertaken using 1 M NaOH traps, capturing ¹⁴CO₂ and a Wallac 1404 liquid scintillation counter to calculate the amount of ¹⁴CO₂ collected. A key result of this study was that L. minor, freshwater, river sediment and trifluralin via PLA-PBAT have equal bioremediation potential compared to bioremediation via PLA-PBAT within soil. Interestingly, PLA-PBAT was the most functional film for potential bioremediation applications due to its higher adsorption of trifluralin, however, LDPE was promising also. Additionally, a 1% trifluralin concentration sorbed best for both plastic film types. PLA-PBAT and L. minor within a water matrix have equal bioremediation potential comparable to PLA-PBAT within soil supporting their possible application for environmental mitigation technologies within a freshwater context.

Date of Award	7 Jun 2024
Original language	English
Awarding Institution	Bangor University
Supervisor	Dave Chadwick (Supervisor) & Davey Jones (Supervisor)