Faculty of Environment Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan, 650500, China; Yunnan Provincial Key Laboratory of Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, Yunnan, China.
Faculty of Resources and Environment, Anhui Agricultural University, Hefei, 230036, Anhui, China; Faculty of Environment Science & Engineering, Kunming University of Science & Technology, Kunming, Yunnan, 650500, China; Yunnan Provincial Key Laboratory of Carbon Sequestration and Pollution Control in Soils, Kunming, 650500, Yunnan, China.
Chemosphere. 2021 Feb;264(Pt 1):128490. doi: 10.1016/j.chemosphere.2020.128490. Epub 2020 Oct 3.
Biochars are one of carbon-rich substances that have attracted enormous attention because of its values in energy storage, carbon sequestration, and environment remediation. Apart from the carbon structure, biochars also contain inherent mineral component and polar functional groups. However, the importance of the inherent minerals to the stability of biochars as well as the sorption of organic compounds remains unclear. In this work, the demineralized treatment by the hydrofluoric acid was employed to remove the inorganic minerals from biochars produced at 300 and 500 °C. The inorganic minerals in biochars were identified and quantified by XRD, XPS and SEM-EDS techniques. Approximately 75% of biochar minerals belonged to the Si- and Al-containing minerals, which connected with carbon skeletons. The impact of these minerals to bisphenol A (BPA) and sulfamethoxazole (SMX) sorption was investigated. The mineral removal decreased BPA sorption but increased SMX sorption. Moreover, the relative contributions of surface adsorption and partition processes were quantified for both compounds through isotherm modeling. The BPA sorption was regulated by the joint effect of adsorption and partition, while more than 82% of the SMX sorption was dominated by the partition process. Such understanding of biochar minerals and carbon structure to the migration of organic contaminants will benefit biochar production and application.
生物炭是富含碳的物质之一，由于其在储能、碳固存和环境修复方面的价值，引起了人们的极大关注。除了碳结构外，生物炭还含有固有矿物质成分和极性官能团。然而，固有矿物质对生物炭稳定性以及有机化合物吸附的重要性尚不清楚。在这项工作中，采用氢氟酸进行脱矿处理，以去除在 300 和 500°C 下制备的生物炭中的无机矿物质。通过 XRD、XPS 和 SEM-EDS 技术对生物炭中的无机矿物质进行了鉴定和定量分析。大约 75%的生物炭矿物质属于含有 Si 和 Al 的矿物质，这些矿物质与碳骨架相连。研究了这些矿物质对双酚 A（BPA）和磺胺甲恶唑（SMX）吸附的影响。矿物质的去除降低了 BPA 的吸附，但增加了 SMX 的吸附。此外，通过等温线模型定量了两种化合物表面吸附和分配过程的相对贡献。BPA 的吸附受吸附和分配的共同作用调节，而超过 82%的 SMX 吸附主要由分配过程决定。这种对生物炭矿物质和碳结构对有机污染物迁移的理解将有利于生物炭的生产和应用。
