Abstract:

Fe₃O₄ nanoparticles and Bi₂O₂CO₃ were used as raw materials for the manufacture of Bi₂O₂CO₃/Fe₃O₄ magnetic composite material by solvothermal method. Its applications for the remediation of the environmental pollutions were discussed, in terms of the removal of the dyes in the dyeing wastewater, the potential positive effects on the anaerobic digestion of the wasted sludge. The Bi₂O₂CO₃/Fe₃O₄ composite material was characterized via X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), and specific surface area and pore size analysis. SEM images showed that the surface of the composite material was rough. The BET result indicated that the specific surface area of the composite material was 9.2294m²/g, and the introduction of Fe₃O₄ largely increased the specific surface area of Bi₂O₂CO₃, resulting in an obvious mesoporous structure. On one hand, the removal efficiencies of the dyes by the composite material with methyl orange (MO) as the target pollutant under different conditions were studied. The maximum adsorption capacity could reach 14.373mg/g. The adsorption reaction is likely to be the pseudo-second-order reaction, which can be described by the Langmuir adsorption isotherm model and characterized as the monolayer adsorption. On the other hand, the effects of composite materials on the methane production potential during anaerobic sludge digestion were evaluated. The addition of composite materials can promote methane production in sludge anaerobic digestion, and the cumulative methane production increased by 10% compared with that of the control group. The first-order kinetic model could well describe Bi₂O₂CO₃/Fe₃O₄-involved the anaerobic digestion process.

Key words: bismuth oxycarbonate/ferroferric oxide (Bi₂O₂CO₃/Fe₃O₄), magnetic material, adsorption, Methyl orange, wasted sludge, anaerobic digestion, methane production potential

摘要：

以Fe₃O₄纳米粒子和Bi₂O₂CO₃为原料，采用溶剂热法制备Bi₂O₂CO₃/Fe₃O₄磁性复合物，并通过对印染废水中染料的去除、剩余污泥厌氧消化过程中产甲烷潜力的影响两方面探讨其在环境污染治理中的应用。借助X射线衍射（XRD）、扫描电镜（SEM）、傅里叶红外光谱（FTIR）和比表面积及孔径分析对Bi₂O₂CO₃/Fe₃O₄复合物进行表征分析，SEM分析结果表明复合物表面较粗糙，BET结果显示复合物的比表面积为9.2294m²/g，Fe₃O₄的引入大幅度增加了Bi₂O₂CO₃的比表面积，使其具有明显的介孔结构。一方面，以甲基橙（MO）为目标污染物，研究了不同实验条件下该材料对染料的去除效果，结果表明，最大吸附量可达14.373mg/g，且该吸附反应过程符合拟二级动力学和Langmuir吸附等温模型，趋于单分子层吸附；另一方面，评估了复合物对污泥厌氧消化产甲烷潜力的影响，结果表明，复合物的引入对污泥厌氧消化产甲烷过程有一定的促进作用，累积产甲烷量相比于对照组提高了10%。分别用一级动力学模型和修正Gompertz模型模拟厌氧消化过程，模拟结果显示一级动力学模型可以更好地描述引入Bi₂O₂CO₃/Fe₃O₄磁性复合物的污泥厌氧消化过程。

关键词: 碳酸氧铋/四氧化三铁, 磁性材料, 吸附, 甲基橙, 剩余污泥, 厌氧消化, 产甲烷潜力