Wei Fan, Wei Enjing, Chen Yuan, Li Jinhui, Tan Quanyin
State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, Beijing 100084, China.
Environ Sci Technol. 2024 Dec 3;58(48):21374-21383. doi: 10.1021/acs.est.4c07430. Epub 2024 Nov 21.
Microplastic (MP), an emerging pollutant, has been identified as a critical target in tackling plastic pollution. Although a plethora of studies have explored MP generation from various sources, limited attention has been paid to plastic processing. This study investigated MP (10 μm-5 mm) generation in virgin and waste plastic extrusion processing. MPs at a density of 2.13 × 10-9.79 × 10 (approximately 0.01-10.85 g) were generated when processing 1 t of plastic. Feedstock sources, polymer types, and pelletizing techniques were found to influence the process. With a moderate weight (270.58-527.34 t) but enormous amount (1.34 × 10-2.63 × 10) of MPs generated globally in 2022, plastic processing is an underestimated but vital source of MPs, emphasizing the need for MP inspection and appropriate removal technologies in the industry, especially for virgin plastic processing and water ring pelletizing. Further simulation indicated that up to 84.35% of MPs could be removed using commonly available materials in the investigated plastic processing facility, with a higher removal efficiency for larger-sized particles. In this regard, plastic recycling was superior to virgin plastic processing with fewer and larger-sized MPs generated, which could facilitate MP removal and should be fostered.
微塑料（MP）作为一种新兴污染物，已被确定为应对塑料污染的关键目标。尽管大量研究探讨了来自各种来源的微塑料生成情况，但对塑料加工过程的关注却很有限。本研究调查了原生塑料和废塑料挤出加工过程中微塑料（10μm - 5mm）的生成情况。加工1吨塑料时会产生密度为2.13×10 - 9.79×10（约0.01 - 10.85克）的微塑料。发现原料来源、聚合物类型和造粒技术会影响该过程。2022年全球塑料加工产生的微塑料重量适中（270.58 - 527.34吨）但数量巨大（1.34×10 - 2.63×10），塑料加工是一个被低估但至关重要的微塑料来源，这凸显了行业中对微塑料进行检测和采用适当去除技术的必要性，特别是对于原生塑料加工和水环造粒过程。进一步的模拟表明，在所研究的塑料加工设施中，使用常见材料可去除高达84.35%的微塑料，对较大尺寸颗粒的去除效率更高。在这方面，塑料回收优于原生塑料加工，产生的微塑料数量更少且尺寸更大，这有利于微塑料的去除，应予以推广。
