形状和尺寸对微塑料大气沉速度的影响
Colette A Preston1, Cheryl L McKenna Neuman1, Julian Aherne1
1School of the Environment, Trent University, Peterborough, Ontario, K9J 0G2, Canada.
Environmental science & technology
|July 31, 2023
概括
大气运输是微塑料 (MP) 的关键途径. 这项研究发现,MP的形状对沉降和漂移有重大影响,挑战现有模型,并表明大气MP的来源来源多样化.
科学领域:
- 环境科学 环境科学
- 大气科学 大气科学
- 材料科学 材料科学 材料科学
背景情况:
- 微塑料 (MP) 在全球污染了各种环境.
- 大气运输是国会议员的重要,但尚未研究的途径.
- 有限的经验数据阻碍了准确的大气MP运输建模.
研究的目的:
- 量化各种微塑料类型的大气沉和水平漂移速度.
- 研究微塑料大小和形状对其大气运输动态的影响.
- 为大气微塑料运输模型的开发和参数化提供经验数据.
主要方法:
- 利用两个定制设计的沉降柱来测量微塑料的行为.
- 采用激光多普勒气流测量仪来准确测量速度.
- 测试了各种微塑料大小和形状,包括球体,圆柱体,薄膜和纤维.
主要成果:
- 微塑料沉速度通常低于现有模型预测的速度.
- 粒子形状是影响结算率和水平漂移的主要因素.
- 观察到尺寸和沉速度之间的线性关系,根据形状而异,偏离功率定律模型.
- 纤维和薄膜显示出更大的水平运动,表明复杂的方向和阻力相互作用.
结论:
- 微塑料的大气传输受到粒子形状的强烈影响,而不仅仅是大小.
- 当前的大气运输模型可能高估了沉速度,低估了漂移.
- 了解形状依赖的动态对于准确的来源归因和全球MP预算评估至关重要.
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