Cerri Mattia, Wille Flora, Arn Silvan, Bucheli Thomas D, Widmer Franco, Werz Rhayn, McNeill Kristopher, Manfrin Alessandro, Sander Michael
Institute of Biogeochemistry and Pollutant Dynamics, Department of Environmental Systems Science, Swiss Federal Institute of Technology Zurich (ETH Zurich), 8092 Zurich, Switzerland.
Environmental Analytics, Agroscope, 8046 Zurich, Switzerland.
Environ Sci Technol. 2025 Apr 29;59(16):8108-8118. doi: 10.1021/acs.est.4c10664. Epub 2025 Apr 18.
Soil biodegradable polyesters are designed to undergo to microbial utilization in aerobic soils, forming carbon dioxide and microbial biomass. These polyesters are thus viable substitutes for conventional, persistent polymers (e.g., polyethylene) in specific applications for which the transfer of some of the polymers into the soil is inevitable. While polymer biodegradability is often assessed in laboratory incubations using respirometric analysis of formed CO, approaches to accurately quantify biodegradable polyesters in soils and to track their mass loss in field incubations over time remain missing. This study first introduces an analytical workflow combining Soxhlet extraction with proton nuclear magnetic resonance spectroscopy for the accurate, high-throughput, and chemically selective quantification of eight commercially important biodegradable polyesters (i.e., poly(butylene adipate--terephthalate), polylactic acid, poly(3-hydroxybutyrate--3-hydroxyhexanoate), poly(3-hydroxybutyrate--3-hydroxyvalerate), polycaprolactone, polybutylene adipate, polybutylene azelate, and polybutylene succinate), and the nonbiodegradable polymer polystyrene, in six soils spanning a range of types and physicochemical properties. This work introduces an effective sample deployment-retrieval approach that, combined with the analytical method, allows the biodegradation of poly(butylene adipate--terephthalate) and polylactic acid from a biodegradable mulch film in three agricultural soils to be monitored. In combination, the two parts of this work lay the foundation to accurately quantify and monitor biodegradable polymers in soils.
土壤可生物降解聚酯的设计目的是在有氧土壤中被微生物利用，形成二氧化碳和微生物生物量。因此，在某些聚合物不可避免地会转移到土壤中的特定应用中，这些聚酯是传统的持久性聚合物（如聚乙烯）的可行替代品。虽然聚合物的生物降解性通常在实验室培养中通过对生成的二氧化碳进行呼吸测定分析来评估，但目前仍缺乏准确量化土壤中可生物降解聚酯并跟踪其在田间培养中随时间的质量损失的方法。本研究首次引入了一种分析流程，将索氏提取与质子核磁共振光谱相结合，用于准确、高通量且具有化学选择性地定量六种具有不同类型和理化性质的土壤中的八种商业上重要的可生物降解聚酯（即聚（丁二酸丁二醇酯-对苯二甲酸酯）、聚乳酸、聚（3-羟基丁酸酯-3-羟基己酸酯）、聚（3-羟基丁酸酯-3-羟基戊酸酯）、聚己内酯、聚丁二酸丁二醇酯、聚壬二酸丁二醇酯和聚丁二酸丁二醇酯）以及不可生物降解的聚合物聚苯乙烯。这项工作引入了一种有效的样品部署-回收方法，该方法与分析方法相结合，能够监测三种农业土壤中可生物降解地膜中的聚（丁二酸丁二醇酯-对苯二甲酸酯）和聚乳酸的生物降解情况。综上所述，本研究的这两个部分为准确量化和监测土壤中的可生物降解聚合物奠定了基础。
