TY - JOUR
T1 - Assessing microplastics contamination and characteristics in organic soil amendments in the Greater Accra Metropolitan Area of Ghana
AU - Fosu-Mensah, Benedicta Yayra
AU - Laryea, Nathanael Nii Odai
AU - Darko, Daniel
AU - Mensah, Michael
N1 - Publisher Copyright:
© 2024
PY - 2024/12/15
Y1 - 2024/12/15
N2 - The study examines the increasing use of organic soil amendments (OSA) due to declining soil fertility and the high cost of synthetic fertilizers, alongside growing concerns about microplastics (MPs) accumulating in soil, which negatively impact soil, crop, and food quality. This research assessed the presence and characteristics of microplastics in Municipal Solid Waste Composts (MSWC) and dry sewage sludge (DSS) within the Greater Accra Metropolitan Area (GAMA) of Ghana. The study analyzed two sources of MSWC (MSWC 1 and MSWC 2) and two sources of DSS (Sludge 1 and Sludge 2), with five samples each, for microplastic concentrations. A reference soil sample, collected from a depth of 0–25 cm, was also tested. The microplastics were extracted using acid digestion (30 % H2O2 at 70 °C), density separation with a ZnCl2 solution, and vacuum filtration. Results revealed that Sludge 1 had the highest concentration of microplastics (4316 ± 968 MP kg−1), followed by MSWC 1 (3572 ± 1196 MP kg−1), MSWC 2 (3104 ± 418 MP kg−1), and Sludge 2 (2024 ± 562 MP kg−1). The soil sample had the lowest concentration of 232 ± 62 MP kg−1. Statistical analyses (Kruskal Wallis and Dunn's multiple comparisons) showed significant differences (p < 0.05) in microplastic concentrations among the samples. The composition of microplastic polymers varied among the samples. The soil sample predominantly contained cellophane (91.67 %) and polyvinyl propionate (8.33 %). MSWC 1 contained urethane alkyd (31.11 %), polyethylene (26.67 %), and polyester (20 %), while MSWC 2 had polyethylene (24.10 %), polyester (20.48 %), cellophane (18.07 %), and polypropylene (15.66 %). Sludge 1 was dominated by polyethylene (35.29 %), polypropylene (30.25 %), cellophane (15.13 %), and urethane alkyd (11.76 %), whereas Sludge 2 mainly contained polyester (42.86 %), cellophane (23.21 %), urethane alkyd (21.43 %), and polyethylene (12.50 %). Microplastics were prevalent in the MSWC and sewage sludge which were obtained from the GAMA, with significantly higher concentrations than those in the soil samples. Further research is needed to develop strategies to mitigate microplastic pollution in OSAs to improve soil health.
AB - The study examines the increasing use of organic soil amendments (OSA) due to declining soil fertility and the high cost of synthetic fertilizers, alongside growing concerns about microplastics (MPs) accumulating in soil, which negatively impact soil, crop, and food quality. This research assessed the presence and characteristics of microplastics in Municipal Solid Waste Composts (MSWC) and dry sewage sludge (DSS) within the Greater Accra Metropolitan Area (GAMA) of Ghana. The study analyzed two sources of MSWC (MSWC 1 and MSWC 2) and two sources of DSS (Sludge 1 and Sludge 2), with five samples each, for microplastic concentrations. A reference soil sample, collected from a depth of 0–25 cm, was also tested. The microplastics were extracted using acid digestion (30 % H2O2 at 70 °C), density separation with a ZnCl2 solution, and vacuum filtration. Results revealed that Sludge 1 had the highest concentration of microplastics (4316 ± 968 MP kg−1), followed by MSWC 1 (3572 ± 1196 MP kg−1), MSWC 2 (3104 ± 418 MP kg−1), and Sludge 2 (2024 ± 562 MP kg−1). The soil sample had the lowest concentration of 232 ± 62 MP kg−1. Statistical analyses (Kruskal Wallis and Dunn's multiple comparisons) showed significant differences (p < 0.05) in microplastic concentrations among the samples. The composition of microplastic polymers varied among the samples. The soil sample predominantly contained cellophane (91.67 %) and polyvinyl propionate (8.33 %). MSWC 1 contained urethane alkyd (31.11 %), polyethylene (26.67 %), and polyester (20 %), while MSWC 2 had polyethylene (24.10 %), polyester (20.48 %), cellophane (18.07 %), and polypropylene (15.66 %). Sludge 1 was dominated by polyethylene (35.29 %), polypropylene (30.25 %), cellophane (15.13 %), and urethane alkyd (11.76 %), whereas Sludge 2 mainly contained polyester (42.86 %), cellophane (23.21 %), urethane alkyd (21.43 %), and polyethylene (12.50 %). Microplastics were prevalent in the MSWC and sewage sludge which were obtained from the GAMA, with significantly higher concentrations than those in the soil samples. Further research is needed to develop strategies to mitigate microplastic pollution in OSAs to improve soil health.
KW - Microplastics
KW - Municipal solid waste compost
KW - Plastic waste
KW - Polymers
KW - Sewage sludge
UR - http://www.scopus.com/inward/record.url?scp=85211035744&partnerID=8YFLogxK
U2 - 10.1016/j.heliyon.2024.e40882
DO - 10.1016/j.heliyon.2024.e40882
M3 - Article
AN - SCOPUS:85211035744
SN - 2405-8440
VL - 10
JO - Heliyon
JF - Heliyon
IS - 23
M1 - e40882
ER -