ABSTRACT

Human hair natural fiber is mainly considered a waste in our society and its disposal can cause a major environmental impact. Hence, its valorization as a biosorbent of pollutants such as heavy metals is an interesting route to explore since it can reduce the amount of waste and at the same time contributes to the circular economy strategy. In this work, the ability of two kinds of human hairs, used as biosorbents to remove Cr(III), Ni(II), Co(II), Mn(II), Cu(II), Zn(II), Cd(II) and Pb(II) ions from multiple-metal aqueous solutions, were examined and compared under different operating conditions. The influence of the time, pH and initial metal concentration on the metal uptake were studied. The biosorption kinetics and isotherm were also modeled observing that pseudo-second-order kinetic model and Langmuir model fitted successfully experimental data. Moreover, biosorption process did not significantly modify the morphology and the chemical structure of the hair samples, which was proved by SEM and FT-IR studies. These kinetic results underline the satisfactory capacity of human hair for the biosorption of Pb(II), Cu(II) and Cr(II) (values up to 95%), pointing up the high efficacy of human hair for the removal of heavy metal ions from aqueous media.

摘要

人类头发天然纤维在我们的社会中主要被认为是一种废物，其处理会造成重大的环境影响。因此，它作为重金属等污染物的生物吸附剂的价值是一个有趣的探索途径，因为它可以减少废物的数量，同时有助于循环经济战略。在这项工作中，两种人类毛发作为生物吸附剂去除 Cr(III)、Ni(II)、Co(II)、Mn(II)、Cu(II)、Zn(II)、Cd( II) 和 Pb(II) 离子来自多金属水溶液，在不同的操作条件下进行了检查和比较。研究了时间、pH和初始金属浓度对金属吸收的影响。还对生物吸附动力学和等温线进行了建模，观察到准二级动力学模型和 Langmuir 模型成功拟合了实验数据。此外，生物吸附过程并没有显着改变头发样品的形态和化学结构，这已通过 SEM 和 FT-IR 研究得到证明。这些动力学结果强调了人类头发对 Pb(II)、Cu(II) 和 Cr(II) 的生物吸附能力令人满意（值高达 95%），表明人类头发去除重金属的高效性水介质中的离子。