Li Cheng, Wang Chunhai, Liu Le
National and Local Joint Engineering Research Center of Biomass Resource Utilization, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Tianjin High-Quality Agricultural Products Development Demonstration Center, Tianjin 301508, China.
Toxics. 2024 Sep 26;12(10):695. doi: 10.3390/toxics12100695.
Microplastics are pollutants of global concern nowadays. However, the effects of microplastics addition to soil as a carbon source and the combined effects of microplastics and organic fertilizer on soil-dissolved organic matter (DOM) evolution are still unclear. This study focused on the evolution of DOM in soil with the addition of microplastics and investigated the variations in the content and composition of DOM in unfertilized and fertilized soil with different particle sizes of microplastics. It was observed that the TOC concentration of the soil DOM in the treatment with organic fertilizer and microplastics increased more (129.97-161.43 mg kg) than that in the treatment with microplastics alone (117.17-131.87 mg kg) and was higher than that in the original soil (95.65 mg kg). According to the humic acid relative abundance in DOM after 40 days of incubation, the humic acid relative abundance in DOM of the soil samples with microplastics and organic fertilizers addition was found to be higher than that in those with microplastic addition alone, reaching more than 80% in a short time. In conclusion, the TOC concentration of the soil DOM increased with the addition of microplastics, and the increase was more pronounced when organic fertilizers and microplastics were added together. Moreover, the soil humification increased to a higher level in the short term with the combined addition of microplastics and organic fertilizers, which was maintained during the long-term incubation process.
微塑料是当今全球关注的污染物。然而，向土壤中添加微塑料作为碳源的影响以及微塑料与有机肥料对土壤溶解性有机 matter (DOM) 演变的综合影响仍不清楚。本研究聚焦于添加微塑料后土壤中 DOM 的演变，并研究了不同粒径微塑料在未施肥和施肥土壤中 DOM 含量和组成的变化。结果表明，有机肥和微塑料处理的土壤 DOM 的 TOC 浓度增加幅度更大（129.97 - 161.43 mg kg），高于单独添加微塑料的处理（117.17 - 131.87 mg kg），且高于原始土壤（95.65 mg kg）。根据培养 40 天后 DOM 中腐殖酸的相对丰度，发现添加微塑料和有机肥的土壤样品 DOM 中腐殖酸的相对丰度高于仅添加微塑料的样品，短时间内可达 80% 以上。总之，添加微塑料会使土壤 DOM 的 TOC 浓度增加，有机肥和微塑料一起添加时增加更为明显。此外，微塑料和有机肥联合添加使土壤腐殖化在短期内提高到更高水平，并在长期培养过程中保持。
