Key Laboratory of Ministry of Education on Pollution Control and Ecosystem Restoration in Industry Clusters, School of Environment and Energy, South China University of Technology, Guangzhou 510006, PR China.
Medical Devices Research and Testing Center, South China University of Technology, Guangzhou 510006, PR China.
Waste Manag. 2020 Dec;118:291-301. doi: 10.1016/j.wasman.2020.08.048. Epub 2020 Sep 9.
Microplastic pollution is ubiquitous and has emerged as a severe global environmental issue. Recent research on microplastic pollution has mainly focused on aquatic ecosystems, while knowledge gaps still exist regarding microplastic in terrestrial environments. In this study, we established a new method for characterizing microplastic in complex soil substrate using FTIR spectroscopy. Microplastic was separated by density without removing soil organic matter to protect microplastic from damage. The Wizards feature was adopted to automatic, direct and continuous characterize micron-size plastic. Furthermore, 33 soil samples were taken from Guiyu, a notorious e-waste dismantling area in Guangdong Province, China, under different land-use. The results showed that microplastic was involved in 30 samples, and the abundance of microplastic varied considerably among different soils, ranged from 0 to 34,100n kg, implying that the e-waste dismantling sites have become the microplastic hotspots. There were 60 kinds of microplastic detected with 6 different shapes and 10 colors, most of which were secondary microplastic. They mainly consisted of engineering-plastic and modified plastic, 88.61% had a size range <1 mm, indicating that the majority of microplastics at Guiyu were derived from e-wastes. The surface morphology of microplastic showed signs of aging and degradation, possibly due to primitive dismantling methods and long-term exposure to the soil. The mean Pb, Cd, Cr, Ba, Cu, Co, As concentrations of microplastic were 20.94, 0.67, 11.82, 308.78, 4.11, 1.26, 3.06 μg·g, respectively. Our findings providescientific basis for monitoring and controlling microplastic pollution in terrestrial environments.
微塑料污染无处不在，已成为严重的全球性环境问题。最近的微塑料污染研究主要集中在水生生态系统，而对于陆地环境中的微塑料，仍存在知识空白。本研究采用傅里叶变换红外光谱法（FTIR）建立了一种新的方法来对复杂土壤基质中的微塑料进行特征描述。该方法在不除去土壤有机质的情况下，通过密度分离来保护微塑料免受损伤。采用 Wizards 特征，可实现微米级塑料的自动、直接和连续特征描述。此外，从中国广东省贵屿这个臭名昭著的电子废物拆解区的不同土地利用类型中采集了 33 个土壤样本。结果表明，30 个样本中都含有微塑料，不同土壤中的微塑料丰度差异很大，范围从 0 到 34100n kg，这意味着电子废物拆解场地已经成为微塑料热点。共检测到 60 种微塑料，具有 6 种不同形状和 10 种颜色，其中大部分为次级微塑料。它们主要由工程塑料和改性塑料组成，88.61%的尺寸范围在<1mm 以内，表明贵屿的大多数微塑料来源于电子废物。微塑料的表面形貌呈现出老化和降解的迹象，这可能是由于原始的拆解方法和长期暴露在土壤中导致的。微塑料中 Pb、Cd、Cr、Ba、Cu、Co、As 的平均浓度分别为 20.94、0.67、11.82、308.78、4.11、1.26、3.06μg·g。本研究结果为监测和控制陆地环境中的微塑料污染提供了科学依据。
