Microplastics profile in sludge from a university wastewater treatment plant and the influence of chemical digestions on Nile red stained microplastics
Microplastics profile in sludge from a university wastewater treatment plant and the influence of chemical digestions on Nile red stained microplastics
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DOI：
10.1016/j.jece.2023.109671
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发表时间：
2023-03
影响因子：
7.7
通讯作者：
Zhiqiang Gao;J. Cizdziel;Lai-guo Chen
中科院分区：
文献类型：
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作者：
Zhiqiang Gao;J. Cizdziel;Lai-guo Chen
许多微塑料（MPs）进入污水处理厂（WWTPs）被困在废污泥中。在这里，我们评估了五种常见的消化方法对尼罗红染色MPs的降解和荧光强度的影响。碎橡胶（CR），醋酸纤维素（CA）和聚酰胺（PA）溶解在酸基消化；聚对苯二甲酸乙二醇酯（PET）、聚乳酸（PLA）和CA在碱溶液中降解；CR被30% H2O2破坏。Fenton试剂对聚合物几乎没有损害，并去除了95%的有机物，使其成为MP分析的最佳选择。然后，我们应用芬顿试剂从密西西比大学现代污水处理厂的初级污泥和脱水污泥中提取MPs。关于大学污水处理厂中MPs的研究有限，其中废水流入和组成因校园活动和人口而有很大差异。假定的MPs丰度范围为13.2±3.8-380.0±46.4颗粒/g（干重），在校园学生的初级污泥和脱水污泥中含量更高。大多数MPs是< 500µm的纤维。通过µftir鉴定了20多种聚合物，其中最丰富的是聚酯（26.4%），尼龙（14.9%）和聚乙烯（12.2%）。随着时间的推移，污泥中聚合物的组成几乎没有变化。总体而言，我们发现Fenton试剂与μ ftir耦合是表征污水处理厂污泥中MPs的有效方法，并且污泥可以根据其处置方式作为环境中MPs的来源。
Many of the microplastics (MPs) entering wastewater treatment plants (WWTPs) become entrained in the waste sludge. Here, we assessed the effects of five common digestion methods on the degradation and fluorescence intensity of Nile-red stained MPs. Crumb rubber (CR), cellulose acetate (CA) and polyamide (PA) dissolved in an acid-based digestion; Polyethylene terephthalate (PET), polylactic acid (PLA) and CA degraded in alkali solutions; and CR was destroyed by 30 % H2O2. Fenton’s reagent resulted in little to no damage to the polymers and removed > 95 % of the organic matter, making it the best choice for MP analyses. We then applied Fenton’s reagent to extract MPs in the primary sludge and dewatered sludge from a modern WWTP at the University of Mississippi. There is limited research on MPs in university WWTPs, where the wastewater inflows and composition vary greatly depending on activities and populations on campus. Abundances of putative MPs ranged from 13.2 ± 3.8–380.0 ± 46.4 particles/g (dry weight), with higher levels in the primary sludge and dewatered sludge with students on campus. The majority of MPs were fibers < 500 µm. Over 20 polymers were identified by using µ-FTIR, with polyester (26.4 %), nylon (14.9 %), and polyethylene (12.2 %) most abundant. There was little change in the composition of polymers in the sludge over time. Overall, we found that Fenton’s reagent coupled with µ-FTIR is an effective approach to characterize MPs in WWTP sludge, and that sludge could serve as a source of MPs to the environment depending on its disposal.