Brazilian Nanotechnology National Laboratory (LNNano) , Brazilian Center for Research in Energy and Materials (CNPEM) , Campinas , São Paulo , Brazil . P.O. Box 6192, 13083-970.
Environ Sci Technol. 2018 Dec 4;52(23):13845-13853. doi: 10.1021/acs.est.8b01524. Epub 2018 Nov 14.
The environmental contamination of soils by polymeric and nanomaterials is an increasing global concern. Polymeric composites containing silver nanoparticles (AgNP) are collectively one of the most important products of nanotechnology due to their remarkable antimicrobial activity. Biochars are a promising resource for environmental technologies for remediation of soils considering their high inorganic and organic pollutant adsorption capacity and microbial soil consortium stimulation. In this work we report, for the first time, the use of biochar material as a tool to accelerate the degradation of polyhydroxybutyrate- co-valerate (PHBV) and PHBV composites containing AgNP in a tropical soil system, under laboratory conditions. This positive effect is associated with microbial community improvement, which increased the degradation rate of the polymeric materials, as confirmed by integrated techniques for advanced materials characterization. The addition of 5-10% of sugarcane bagasse biochar into soil has increased the degradation of these polymeric materials 2 to 3 times after 30 days of soil incubation. However, the presence of silver nanoparticles in the PHBV significantly reduced the degradability potential of this nanocomposite by the soil microbial community. These results provide evidence that AgNP or Ag ions caused a decline in the total number of bacteria and fungi, which diminished the polymer degradation rate in soil. Finally, this work highlights the great potential of biochar resources for application in soil remediation technologies, such as polymeric (nano)material biodegradation.
土壤中聚合物和纳米材料的环境污染是一个日益引起全球关注的问题。由于其显著的抗菌活性，含有银纳米粒子（AgNP）的聚合物复合材料是纳米技术最重要的产品之一。生物炭是一种很有前途的环境修复技术资源，因为它具有高无机和有机污染物吸附能力和微生物土壤共生体刺激作用。在这项工作中，我们首次报道了在实验室条件下，生物炭材料作为一种工具，用于加速聚羟基丁酸酯-共-戊酸酯（PHBV）和含有 AgNP 的 PHBV 复合材料在热带土壤系统中的降解。这种积极的影响与微生物群落的改善有关，这增加了聚合物材料的降解速率，这一点通过先进材料特性的综合技术得到了证实。在土壤中添加 5-10%的甘蔗渣生物炭，可使这些聚合物材料在 30 天的土壤培养后，降解速度提高 2 到 3 倍。然而，PHBV 中银纳米粒子的存在显著降低了土壤微生物群落对这种纳米复合材料的可降解性。这些结果表明，AgNP 或 Ag 离子导致细菌和真菌总数减少，从而降低了土壤中聚合物的降解速率。最后，这项工作强调了生物炭资源在土壤修复技术中的巨大应用潜力，例如聚合物（纳米）材料的生物降解。
