Abstract This study was developed based on the possibility of reusing and valuing the alginate extraction residue (RES) from the algae Sargassum filipendula. The adsorptive properties of RES were explored through kinetic and equilibrium assays in batch mode, in which the kinetic equilibrium time (200 min) was not influenced by the increase of the initial concentration of Ni solutions and the sorption process was favored by the temperature increase. The modeling revealed the simultaneous occurrence of physical and chemical interactions with the external diffusion as the predominant step. The Langmuir model was more representative for the equilibrium results, with an uptake capacity comparable to that of other biomaterials. The thermodynamic study indicated a spontaneous, favorable, and endothermic process, besides the presence of the ion exchange. The isoelectric point was found at pH 5.3, and the pore size distribution allowed the classification of RES as macroporous. The simplified bath sorption design revealed that the required mass of RES become greater for higher quality degrees. However, it is tenable to consider this process viable due to the easy access to the algae biomass and the large amount of the solid waste generated from the alginate extraction (∼50%), termed as residue (RES).

中文翻译：

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马尾藻藻酸盐提取废料的再利用用于 Ni(II) 生物吸附

摘要 本研究是基于对来自马尾藻的藻酸盐提取残渣 (RES) 进行再利用和评估的可能性而开展的。RES 的吸附性能通过动力学和平衡试验以批模式进行探索，其中动力学平衡时间（200 分钟）不受 Ni 溶液初始浓度增加的影响，吸附过程受温度升高的影响。该模型揭示了物理和化学相互作用同时发生，外部扩散是主要步骤。Langmuir 模型对平衡结果更具代表性，其吸收能力与其他生物材料相当。热力学研究表明，除了离子交换的存在外，还有一个自发的、有利的和吸热的过程。等电点在 pH 5.3 时发现，孔径分布允许将 RES 分类为大孔。简化的浴吸附设计表明，对于更高的质量等级，所需的 RES 质量变得更大。然而，由于易于获得藻类生物质以及藻酸盐提取产生的大量固体废物（~50%），称为残留物（RES），因此认为该过程可行是站得住脚的。