The adsorption of a new antibiotic, daptomycin, on two magnetic ultra-fine wood-based biochars were investigated in detail using batch experiments. The adsorbent materials was prepared by ball milling method, which was characterized by laser particle size analyzer, elemental analyzer, ICP-OES, VSM, BET, TG-DTG, FTIR and SEM. Furthermore, the effects of most important variables in the adsorption process, including solution pH, contact time, initial concentration and temperatures were investigated. The results exhibited that the adsorption of daptomycin was highly pH-dependent, and the capacity decreased with increasing pH. The adsorption process follows pseudo-first order and pseudo-second order models, analysis indicated that their adsorption was dominantly by physisorption. Equilibrium data were fitted well with Freundlich isotherm model, implying a multilayer adsorption. Thermodynamic parameters demonstrated that the adsorption was spontaneous, endothermic and increased randomness process. Mechanism study suggested the boundary layer diffusion was the rate limiting step.

中文翻译：

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水中磁性超细木基生物炭对达托霉素的吸附：动力学、等温线和机理研究


通过批量实验详细研究了两种磁性超细木基生物炭对新型抗生素达托霉素的吸附。采用球磨法制备吸附材料，采用激光粒度分析仪、元素分析仪、ICP-OES、VSM、BET、TG-DTG、FTIR、SEM等手段进行表征。此外，还研究了吸附过程中最重要变量的影响，包括溶液 pH 值、接触时间、初始浓度和温度。结果表明，达托霉素的吸附具有很强的pH依赖性，并且随着pH的增加，吸附容量降低。吸附过程遵循准一级和准二级模型，分析表明其吸附以物理吸附为主。平衡数据与 Freundlich 等温线模型吻合良好，表明存在多层吸附。热力学参数表明吸附是自发的、吸热的、随机性增加的过程。机理研究表明边界层扩散是限速步骤。