The adsorption process is one of the most promising alternatives for textile effluent treatment. Different materials have been used as adsorbents and most of them present hard recovery, increasing the process cost. In this work, polyethylene terephthalate (PET) waste bottles were used as a substrate for the formation of titanium dioxide (TiO₂-G5) films aiming at Reactive Black 5 removal by adsorption process. The TiO₂-G5/PET films were characterized by N₂ adsorption-desorption, zeta potential analysis, X-ray diffraction (XRD), and adherence test. The pH, adsorbent charge, and stirring effects were investigated. Initially, the effects of the adsorbent mass, pH of the solution, and stirring were studied, obtaining a maximum adsorptive capacity of 155.04 mg g⁻¹ in the greatest condition (4 mg, pH = 4 and no stirring). The experimental data were fitted by the Langmuir and Freundlich isotherms. The Langmuir model presented the greatest fit, evidencing monolayer adsorption for this process. The kinetic study showed a great fit between the adsorption process and the pseudo-first-order kinetic model, which presented a correlation coefficient of 0.982. The thermodynamic parameters—enthalpy (∆H = − 19.53 kJ mol⁻¹), entropy (∆S = − 50.26 J mol⁻¹ K⁻¹), and Gibbs energy (− 5.31, − 4.80, and − 4.30 kJ mol⁻¹ at 283.15 K, 293.15 K, and 303.15 K, respectively)—indicate a spontaneous and exothermic process. Finally, the regeneration by solar radiation exposure led to an efficient TiO2-G5/PET spent sheets recovery, exhibiting good stability after 5 cycles of use.

吸附工艺是纺织品废水处理的最有希望的替代方法之一。已经使用了不同的材料作为吸附剂，其中大多数具有硬回收率，从而增加了工艺成本。在这项工作中，聚对苯二甲酸乙二酯（PET）废瓶用作形成二氧化钛（TiO ₂ -G5）薄膜的基材，旨在通过吸附工艺去除活性黑5。通过N ₂吸附-脱附，ζ电位分析，X射线衍射（XRD）和附着力测试对TiO ₂ -G5 / PET薄膜进行了表征。研究了pH，吸附剂电荷和搅拌效果。最初，研究了吸附剂质量，溶液的pH值和搅拌的影响，获得的最大吸附容量为155.04 mg g。^-1在最大条件下（4 mg，pH = 4且无搅拌）。实验数据由Langmuir和Freundlich等温线拟合。Langmuir模型表现出最大的适应性，证明了该过程的单层吸附。动力学研究表明，吸附过程与拟一级动力学模型非常吻合，相关系数为0.982。热力学参数-焓（∆H = − 19.53 kJ mol ^-1），熵（∆S = − 50.26 J mol ^-1  K ^-1）和吉布斯能量（− 5.31，− 4.80和− 4.30 kJ mol ^-1分别为283.15 K，293.15 K和303.15 K）—表示自发和放热过程。最后，通过暴露于太阳辐射下的再生可有效回收TiO2-G5 / PET废纸，在使用5个循环后表现出良好的稳定性。