TY - JOUR
T1 - Oleo-extraction of microplastics using flotation plus sol-gel technique to confine small particles in silicon dioxide gel
AU - Pacaphol, Kamonwan
AU - Aht-Ong, Duangdao
AU - Coughlan, Darcy
AU - Hoogewerff, Jurian
N1 - Publisher Copyright:
© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
Funding Information:
The authors appreciate the National Centre for Forensic Studies (NCFS), Faculty of Science and Technology, University of Canberra, Australian Capital Territory, Australia, and the Department of Materials Science, Faculty of Science, Chulalongkorn University, Thailand, and Hub of Talent: Sustainable Materials for Circular Economy, National Research Council of Thailand (NRCT) for laboratory facilities and instruments.
Publisher Copyright:
© The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.
PY - 2024/11
Y1 - 2024/11
N2 - Extracting microplastics from natural sources is challenging, especially microplastics with sizes smaller than 100 μm. The flotation method is the most common microplastic extraction, but it struggles with fine particles due to the difficulty in collecting floating plastic particles from the liquid during the separation process. This study proposes a new floating media, tetraethyl orthosilicate (TEOS), that could separate microplastics using its hydrophobic-oleophilic properties. Most interestingly, TEOS transformed from a liquid state to a solid state (gel) by hydrolysis and condensation reactions, thus safely capturing the separated microplastic particles after flotation and mitigating particle loss from scooping since its gel acted as a particle holder. The average recovery rates obtained were in the range of 95–100% for polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polytetrafluoroethylene, and aged tyre rubber. The recovery rates were slightly reduced for finer particles (sizes down to 40 μm) at 82–98%. TEOS-based extraction provided a higher recovery rate for non-polar plastics than for polar or hydrophilic plastics. The separated microplastics maintained their characteristics for polymer identification, as proven by spectroscopic and thermal analysis techniques. Therefore, TEOS-based extraction could be a new approach to microplastic extraction, especially for preventing fine particle loss. Graphical abstract: (Figure presented.)
AB - Extracting microplastics from natural sources is challenging, especially microplastics with sizes smaller than 100 μm. The flotation method is the most common microplastic extraction, but it struggles with fine particles due to the difficulty in collecting floating plastic particles from the liquid during the separation process. This study proposes a new floating media, tetraethyl orthosilicate (TEOS), that could separate microplastics using its hydrophobic-oleophilic properties. Most interestingly, TEOS transformed from a liquid state to a solid state (gel) by hydrolysis and condensation reactions, thus safely capturing the separated microplastic particles after flotation and mitigating particle loss from scooping since its gel acted as a particle holder. The average recovery rates obtained were in the range of 95–100% for polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polytetrafluoroethylene, and aged tyre rubber. The recovery rates were slightly reduced for finer particles (sizes down to 40 μm) at 82–98%. TEOS-based extraction provided a higher recovery rate for non-polar plastics than for polar or hydrophilic plastics. The separated microplastics maintained their characteristics for polymer identification, as proven by spectroscopic and thermal analysis techniques. Therefore, TEOS-based extraction could be a new approach to microplastic extraction, especially for preventing fine particle loss. Graphical abstract: (Figure presented.)
KW - Fine microplastic particles
KW - Flotation
KW - Gel
KW - Microplastic extraction
KW - Oleophilicity
KW - Silane
KW - TEOS
KW - Tetraethyl orthosilicate
UR - http://www.scopus.com/inward/record.url?scp=85206799609&partnerID=8YFLogxK
U2 - 10.1007/s11356-024-35276-5
DO - 10.1007/s11356-024-35276-5
M3 - Article
AN - SCOPUS:85206799609
SN - 0944-1344
VL - 31
SP - 61096
EP - 61113
JO - Environmental Science and Pollution Research
JF - Environmental Science and Pollution Research
IS - 51
ER -