TY - JOUR
T1 - Temporal and spatial distribution of microplastics in green infrastructures
T2 - Rain gardens
AU - Parameswarappa Jayalakshmamma, Meghana
AU - Na Nagara, Viravid
AU - Borgaonkar, Ashish
AU - Sarkar, Dibyendu
AU - Obropta, Christopher
AU - Boufadel, Michel
N1 - Publisher Copyright:
© 2024 Elsevier Ltd
PY - 2024/8
Y1 - 2024/8
N2 - Rain gardens, a type of green infrastructure (GI), have been recognized for mitigating flooding and improving water quality from minor storms by trapping stormwater pollutants. Yet, the capability of these systems to retain microplastics (MPs) from stormwater, especially in size <125 μm, remains inadequately understood. This study investigated the spatial and temporal distributions of MPs in three rain gardens located in Newark, New Jersey, USA. The rain gardens have been in operation for ∼7 years and located in different land uses: low-density residential (Site 1), commercial (Site 2), and high-density residential (Site 3). The sediment samples were collected during May 2022, August 2022, and February 2023 at various soil depths and horizontal distances of rain gardens. The MPs were quantified and characterized using Fourier transform infrared (FTIR) spectrometer and a Raman microscope. The overall mean concentration varied between sampling sites, with 469 ± 89.8 pkg−1 in Site 1, 604 ± 91.4 pkg−1 in Site 2, and 997 ± 64.3 pkg−1 in Site 3, with Polypropylene as the dominant polymer, followed by nylon and polyethylene. In the vertical direction, larger MPs (250 μm–5 mm) were effectively retained within the top 5 cm and their concentration declined exponentially with the increasing depths. Small-sized MPs (1–250 μm) were prevalent at deeper depths (≥ 10 cm), and no MPs were found below 15 cm. In the horizontal direction, the highest MP concentration was observed near the stormwater inlet, and the concentration decreased away from the inlet. Over the nine-month period, a notable increase in concentration was observed at all sites. These findings contribute valuable knowledge towards developing effective measures for retaining MPs from stormwater and monitoring GIs in urban environments.
AB - Rain gardens, a type of green infrastructure (GI), have been recognized for mitigating flooding and improving water quality from minor storms by trapping stormwater pollutants. Yet, the capability of these systems to retain microplastics (MPs) from stormwater, especially in size <125 μm, remains inadequately understood. This study investigated the spatial and temporal distributions of MPs in three rain gardens located in Newark, New Jersey, USA. The rain gardens have been in operation for ∼7 years and located in different land uses: low-density residential (Site 1), commercial (Site 2), and high-density residential (Site 3). The sediment samples were collected during May 2022, August 2022, and February 2023 at various soil depths and horizontal distances of rain gardens. The MPs were quantified and characterized using Fourier transform infrared (FTIR) spectrometer and a Raman microscope. The overall mean concentration varied between sampling sites, with 469 ± 89.8 pkg−1 in Site 1, 604 ± 91.4 pkg−1 in Site 2, and 997 ± 64.3 pkg−1 in Site 3, with Polypropylene as the dominant polymer, followed by nylon and polyethylene. In the vertical direction, larger MPs (250 μm–5 mm) were effectively retained within the top 5 cm and their concentration declined exponentially with the increasing depths. Small-sized MPs (1–250 μm) were prevalent at deeper depths (≥ 10 cm), and no MPs were found below 15 cm. In the horizontal direction, the highest MP concentration was observed near the stormwater inlet, and the concentration decreased away from the inlet. Over the nine-month period, a notable increase in concentration was observed at all sites. These findings contribute valuable knowledge towards developing effective measures for retaining MPs from stormwater and monitoring GIs in urban environments.
KW - Accumulation
KW - Bioretention
KW - Microplastics
KW - Rain gardens
KW - Stormwater
UR - http://www.scopus.com/inward/record.url?scp=85196822250&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85196822250&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2024.142543
DO - 10.1016/j.chemosphere.2024.142543
M3 - Article
C2 - 38866339
AN - SCOPUS:85196822250
SN - 0045-6535
VL - 362
JO - Chemosphere
JF - Chemosphere
M1 - 142543
ER -