Department of Civil and Environmental Engineering, Faculty of Engineering, Mahidol University, Nakhonpathom 73710, Thailand.
Faculty of Environment and Resource Studies, Mahidol University, Nakhonpathom 73710, Thailand.
Sci Total Environ. 2022 Dec 20;853:158642. doi: 10.1016/j.scitotenv.2022.158642. Epub 2022 Sep 9.
Microplastic pollution is recognized as an emerging global issue; however, no standardized method for the extraction of these pollutants from the environment currently exists and existing methods are ineffective for specific environmental matrices. An appropriate organic matter removal method is essential for the extraction of microplastics from organic-rich sludge to minimize interference during their identification and enhance compatibility of the identification steps. The present study aimed to establish an effective technique for the digestion of organic matter-rich sludge using hydrogen peroxide and Fenton's reagent at varying temperatures, times, and concentrations of an iron catalyst. The organic matter removal efficiency of the five protocols utilized varied from 81.5 % to 87.1 %. Polymers such as polyvinyl chloride (PVC), high density polyethylene (HDPE), low density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) retained most of their physical and chemical properties after the treatments, with minor changes in the surface area, weight, and FTIR spectra properties. Polyethylene terephthalate (PET), PET fiber, polyamide (PA) fiber, and polymethyl methacrylate (PMMA) fiber were significantly degraded via treating with HO at 50 °C for 24 h. Protocol 4, treating with Fenton's reagent (HO (30 %) + (0.05 M) FeSO.7HO) at 50 °C for 1 h is proposed as a rapid and effective method for the removal of organic matter from sludge. In addition to its rapidity, this method minimally impacts most polymers, and its high organic matter removal efficiency is associated with a significant reduction of suspended solids in sludge. The present study provides a validated approach that facilitates as an effective organic removal step during the extraction of MPs in sludge.
微塑料污染被认为是一个新出现的全球性问题；然而，目前还没有从环境中提取这些污染物的标准化方法，现有的方法对特定的环境基质效果不佳。从富含有机物的污泥中提取微塑料时，需要采用适当的有机物去除方法，以最大限度地减少识别过程中的干扰，并提高识别步骤的兼容性。本研究旨在建立一种使用过氧化氢和芬顿试剂在不同温度、时间和铁催化剂浓度下消化富含有机物污泥的有效技术。五种方案中使用的有机物去除效率从 81.5%到 87.1%不等。聚氯乙烯（PVC）、高密度聚乙烯（HDPE）、低密度聚乙烯（LDPE）、聚丙烯（PP）和聚苯乙烯（PS）等聚合物在经过处理后保留了大部分物理和化学性质，仅表面积、重量和傅里叶变换红外（FTIR）光谱特性略有变化。聚对苯二甲酸乙二醇酯（PET）、PET 纤维、聚酰胺（PA）纤维和聚甲基丙烯酸甲酯（PMMA）纤维在 50°C 下用 HO 处理 24 小时后显著降解。方案 4，即使用 Fenton 试剂（HO（30%）+（0.05 M）FeSO4·7H2O）在 50°C 下处理 1 小时，被提议作为一种快速有效的去除污泥中有机物的方法。除了快速之外，这种方法对大多数聚合物的影响最小，其高有机物去除效率与污泥中悬浮固体的显著减少有关。本研究提供了一种经过验证的方法，可作为从污泥中提取 MPs 过程中的有效有机物去除步骤。
