Abstract：
Resource utilization of waste masks has become an urgent scientific issue. In this work, with sustainably, waste masks and biomass were co-pyrolysis with oxygen limitation to prepare mask-based biochar (MB). Then, urea was introduced to prepare novel nitrogen modified mask-based biochar (NMB) via a one-step hydrothermal synthesis method. The adsorption characteristics of NMB on the emerging environmental pollutant, bisphenol A (BPA), were evaluated via batch adsorption tests. Moreover, the physicochemical properties of the materials were characterized with various advanced techniques. Also, the roles of waste masks and nitrogen modification were explored. The adsorption mechanisms of NMB on BPA were revealed as well as the performance differences between different adsorbents. The results showed that waste masks participated in thermochemical reactions, shaped the microsphere structure of biochar, and increased the types of surface functional groups. The nitrogen modification enriched the surface elemental composition and activated the specific surface area via the mesopore. These would enhance the adsorption performance. The maximum adsorption of BPA by NMB was 62.63 mg·g-1, which was approximately 2.35-5.58 times higher than that of the control materials. Temkin model and pseudo-second-order model optimally simulate the isothermal and kinetic adsorption, respectively. The adsorption mechanisms are jointly by physical and chemical adsorption, which mainly includes π-π interaction, hydrogen bonding, intraparticle diffusion, surface adsorption, and ion exchange. After discussion and evaluation, NMB has lower preparation process cost (7.21 USD·kg-1) and safety, with potential for environmental applications. This study aims to expand new ideas for the comprehensive utilization of waste masks and the preparation of eco-friendly materials. Moreover, it provides a theoretical basis for the removal of BPA.
摘要：
废弃口罩的资源化利用已成为一个紧迫的科学问题。在这项工作中,可持续的,将废弃口罩和生物质与限氧共热解制备口罩基生物炭(MB)。然后，引入尿素，通过一步水热合成法制备新型氮改性掩模基生物炭（NMB）。研究了NMB对新兴环境污染物的吸附特性,双酚A(BPA),通过批量吸附测试进行评估。此外，用各种先进技术表征了材料的物理化学性能。此外，探讨了废弃口罩和氮改性的作用。揭示了NMB对BPA的吸附机理以及不同吸附剂之间的性能差异。结果表明，废弃口罩参与了热化学反应，塑造了生物炭的微球结构，并增加了表面官能团的类型。氮改性富集了表面元素组成，并通过中孔激活了比表面积。这些将增强吸附性能。NMB对BPA的最大吸附量为62.63mg·g-1，是对照材料的2.35-5.58倍。Temkin模型和伪二阶模型优化模拟了等温和动力学吸附,分别。吸附机理是物理和化学吸附共同作用的,主要包括π-π相互作用，氢键,粒子内扩散，表面吸附，和离子交换。经过讨论和评估，NMB具有较低的制备工艺成本（7.21USD·kg-1）和安全性，具有环境应用的潜力。本研究旨在为废弃口罩的综合利用和环保材料的制备拓展新思路。此外，为BPA的去除提供了理论依据。
