DOI: 10.1016/j.watres.2018.07.007
Scopus记录号: 2-s2.0-85053035871
论文题名: Size-dependent transport and retention of micron-sized plastic spheres in natural sand saturated with seawater
作者: Dong Z. ; Qiu Y. ; Zhang W. ; Yang Z. ; Wei L.
刊名: Water Research
ISSN: 431354
出版年: 2018
卷: 143 起始页码: 518
结束页码: 526
语种: 英语
英文关键词: Marine salinity
; Microplastics
; Natural sea sand
; Retention
; Seawater
; Transport
Scopus关键词: Deionized water
; Effluents
; Energy barriers
; Seawater
; Marine salinity
; Microplastics
; Retention
; Sea sand
; Transport
; Sand
; concentration (composition)
; effluent
; experimental study
; marine environment
; plastic
; salinity
; seawater
; vertical migration
英文摘要: A series of one-dimensional column experiments were conducted to investigate the transport and retention of micron-sized plastic spheres (MPs) with diameters of 0.1–2.0 μm in seawater-saturated sand. In seawater with salinity of 35 PSU (practical salinity units), the mass percentages recovered from the effluent (Meff) of the larger MPs increased from 13.6% to 41.3%, as MP size decreased from 2.0 μm to 0.8 μm. This occurred because of the gradual reduction of physical straining effect of MPs in the pores between sands. The smaller MPs (0.6, 0.4, and 0.1 μm) showed the stronger inhibition of MPs mobility, with Meff values of 11.5%, 11.9%, and 9.8%, respectively. This was due to the lower energy barriers (from 108 kBT to 16 kBT) between the smaller MPs and the sand surface, when compared with the larger MPs (from 296 kBT to 161 kBT). In particular, the aggregation of MPs (0.6 or 0.4 μm) triggered a progressive decrease in MP concentration in the effluent. Retention experiments showed that the vertical migration distance of most MP colloids was 0–4 cm at the inlet of column. For 0.6 or 0.4 μm MPs, the particles were concentrated over a 0–2 cm vertical distance. Moreover, the salinity (35–3.5 PSU) did not affect the transport of the larger MPs (2.0–0.8 μm). However, as seawater salinity decreased from 35 PSU to 17.5 or 3.5 PSU, the aggregation of the smaller MPs (0.6–0.1 μm) was dramatically inhibited or completely prevented. Meanwhile, ripening of the sand surface by the MPs (0.6 and 0.4 μm) no longer occurred. By contrast, all MPs in deionized water (0 PSU) achieved complete column breakthroughs because of the strong repulsive energy barrier (from 218 kBT to 4192 kBT) between the MPs and the sand surface. Consequently, we find that the transport and retention of MPs in sandy marine environment strongly relies on both the MP size and the salinity levels. © 2018 Elsevier Ltd Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/112583
Appears in Collections: 气候减缓与适应
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作者单位: State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China; School of Materials Science and Engineering, Jiading Campus, Tongji University, Shanghai, 201804, China
Recommended Citation:
Dong Z.,Qiu Y.,Zhang W.,et al. Size-dependent transport and retention of micron-sized plastic spheres in natural sand saturated with seawater[J]. Water Research,2018-01-01,143