PMID- 35970352
OWN - NLM
STAT- MEDLINE
DCOM- 20220914
LR  - 20221207
IS  - 1873-6424 (Electronic)
IS  - 0269-7491 (Linking)
VI  - 311
DP  - 2022 Oct 15
TI  - Enhanced settling of microplastics after biofilm development: A laboratory column 
      study mimicking wastewater clarifiers.
PG  - 119909
LID - S0269-7491(22)01123-X [pii]
LID - 10.1016/j.envpol.2022.119909 [doi]
AB  - The settling of microplastics (MPs) is crucial for their removal from municipal 
      wastewater treatment plants (WWTPs) and sedimentation in static waterbodies, 
      where they can accumulate in bottom sediments. Biofilm formation on MPs enhances 
      their aggregation with other particles, thereby changing their density and size 
      and altering their settling rates. However, only a few studies have investigated 
      the settling of MPs of different sizes and materials. Specifically, the settling 
      of small-sized MPs (<150 mum) has been poorly documented. In this study, 
      cylindrical and fragmented particles of four polymer types (high-density 
      polyethylene (HDPE), polypropylene (PP), polystyrene (PS), and poly(ethylene 
      terephthalate) (PET)) were used to investigate the settling or floating of 
      reference MPs (20-130 mum) in a custom-made column that simulated a primary 
      sedimentation tank in a typical WWTP before and after incubation in wastewater 
      influent. The settling velocity of the reference MP particles was strongly 
      influenced by the particle size and density. The settled fractions of all the 
      cylindrical reference MPs increased significantly (up to 5 times) due to biofilm 
      formation at overflow velocities of 0.15, 0.26, and 0.40 mm s(-1). This was 
      observed even for HDPE and PP (density <1 g cm(-3)) after biofilm formation. The 
      fragmented reference MPs showed complex and rather unpredictable behavior, 
      possibly due to their irregular shape. Generally, the settling of pristine PS and 
      PET in the laboratory tests was consistent with the theoretical predictions 
      obtained using Stokes' law. The experimental findings of this study can be used 
      to develop models that predict the removal efficiencies of MPs in WWTPs and to 
      estimate the sinking of MPs to bottom sediments of static waterbodies.
CI  - Copyright (c) 2022 Elsevier Ltd. All rights reserved.
FAU - Lee, So-Young
AU  - Lee SY
AD  - Division of Environmental Science and Ecological Engineering, Korea University, 
      145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
FAU - An, Jiyul
AU  - An J
AD  - Division of Environmental Science and Ecological Engineering, Korea University, 
      145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
FAU - Kim, Jinwoo
AU  - Kim J
AD  - Division of Environmental Science and Ecological Engineering, Korea University, 
      145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea.
FAU - Kwon, Jung-Hwan
AU  - Kwon JH
AD  - Division of Environmental Science and Ecological Engineering, Korea University, 
      145 Anam-ro, Seongbuk-gu, Seoul, 02841, Republic of Korea. Electronic address: 
      junghwankwon@korea.ac.kr.
LA  - eng
PT  - Journal Article
DEP - 20220812
PL  - England
TA  - Environ Pollut
JT  - Environmental pollution (Barking, Essex : 1987)
JID - 8804476
RN  - 0 (Microplastics)
RN  - 0 (Plastics)
RN  - 0 (Waste Water)
RN  - 0 (Water Pollutants, Chemical)
RN  - 9002-88-4 (Polyethylene)
SB  - IM
MH  - Biofilms
MH  - Environmental Monitoring
MH  - *Microplastics
MH  - Plastics
MH  - Polyethylene
MH  - Waste Disposal, Fluid
MH  - Wastewater
MH  - *Water Pollutants, Chemical/analysis
OTO - NOTNLM
OT  - Aggregation
OT  - Biofilm
OT  - Freshwater
OT  - Microplastics
OT  - Settling velocity
OT  - Wastewater treatment plants
COIS- Declaration of competing interest The authors declare that they have no known 
      competing financial interests or personal relationships that could have appeared 
      to influence the work reported in this paper.
EDAT- 2022/08/16 06:00
MHDA- 2022/09/15 06:00
CRDT- 2022/08/15 19:26
PHST- 2022/05/14 00:00 [received]
PHST- 2022/07/21 00:00 [revised]
PHST- 2022/08/03 00:00 [accepted]
PHST- 2022/08/16 06:00 [pubmed]
PHST- 2022/09/15 06:00 [medline]
PHST- 2022/08/15 19:26 [entrez]
AID - S0269-7491(22)01123-X [pii]
AID - 10.1016/j.envpol.2022.119909 [doi]
PST - ppublish
SO  - Environ Pollut. 2022 Oct 15;311:119909. doi: 10.1016/j.envpol.2022.119909. Epub 
      2022 Aug 12.