Adsorption of cyanotoxins on polypropylene and polyethylene terephthalate : microplastics as vector of eight microcystin analogues
Abstract
Plastics are utilised globally but are of environmental concern due to their persistence. The global presence of microplastics (particles <5 mm in all dimensions) in freshwater environments is increasingly reported, as has the presence of cyanobacterial toxins, including the microcystins. We elucidated the potential role of microplastics as a vector for eight microcystin analogues. Two sizes of polypropylene (PP) and polyethylene terephthalate (PET) microparticles were evaluated. The median particle size distribution (D50) was 8–28 μm for small particles, and 81–124 μm for large particles. Additionally, microcystin-LR and -LF were evaluated individually using small PP and PET to elucidate the adsorption behaviour in the absence of competition. Microcystin hydrophobicity, polymer material, and particle size were key factors influencing adsorption to the plastic microparticles. The small size PP microparticles demonstrated a high affinity for the 8 microcystin analogues. The proportion of microcystin adsorbed onto the small particles of PP after 48 h contact was between 83 and 100%, depending on the analogue. Of all analogues investigated, only microcystin-LW and -LF adsorbed onto the larger sized PP and PET microparticles. Individually, greater amounts of MC-LF adsorbed onto the small PET (19%) compared to when it was present in the mixture of microcystins (11%). While MC-LR did not adsorb onto small PET microparticles in the mixture, 5% adsorption was observed when individually in contact with small PET microparticles. The results demonstrated that microplastics can adsorb eight different microcystin analogues and that more hydrophobic analogues are more likely to adsorb than less hydrophobic analogues.
Citation
Moura , D S , Pestana , C J , Moffat , C F , Hui , J , Irvine , J T S , Edwards , C & Lawton , L A 2022 , ' Adsorption of cyanotoxins on polypropylene and polyethylene terephthalate : microplastics as vector of eight microcystin analogues ' , Environmental Pollution , vol. 303 , 119135 . https://doi.org/10.1016/j.envpol.2022.119135
Publication
Environmental Pollution
Status
Peer reviewed
ISSN
0269-7491Type
Journal article
Description
The authors would like to thank the Scottish Goverment's Hydro Nation Scholars Programme for funding this research. The authors would like to thank the Engineering and Physical Sciences Research Council (EPSRC) [EP/P029280/1].Collections
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