School of Chemistry and Food, Federal University of Rio Grande-FURG, km 8, Italia Avenue, 96203-900 Rio Grande, RS, Brazil.
Chemical Engineering Department, Federal University of Santa Maria, UFSM, Roraima Avenue, 1000, 97105-900 Santa Maria, RS, Brazil.
Int J Biol Macromol. 2020 Jan 1;142:85-93. doi: 10.1016/j.ijbiomac.2019.09.074. Epub 2019 Oct 5.
This work developed one promising adsorbent based on chitosan hydrogel scaffold modified with carbon nanotubes, for food dye removal in single and binary aqueous systems. The modified hydrogel scaffold was characterized in relation to the gel strength, swelling degree, surface attributes, and infrared spectrum. Adsorption isotherms were performed using dyes, food red 17 (FdR17) and food blue 1 (FdB1), in single and binary aqueous systems. The experimental data were adjusted to the Langmuir model and the thermodynamic parameters were estimated. The kinetic behavior was evaluated and, desorption studies were performed to verify the reuse capacity of the modified hydrogel scaffold. The results showed that maximum adsorption capacities were of 1508 and 1480 mg g for the single system and of 955 and 902 mg g for the binary system, for FdB1 and FbR17, respectively. The thermodynamic parameters indicated that the adsorption was the spontaneous, exothermic and favorable process. The model that best represented the kinetic data was that of Avrami. In desorption, the adsorbent can be used until four times and maintaining the adsorption capacity of the adsorbent in 71% of the initial capacity.
本工作开发了一种基于壳聚糖水凝胶支架的有前途的吸附剂，用于在单一和二元水体系中去除食品染料。对改性水凝胶支架的凝胶强度、溶胀度、表面特性和红外光谱进行了表征。在单一和二元水体系中，使用染料食品红 17（FdR17）和食品蓝 1（FdB1）进行了吸附等温线实验。实验数据采用朗缪尔模型进行了调整，并估算了热力学参数。评价了动力学行为，并进行了解吸研究以验证改性水凝胶支架的可重复使用能力。结果表明，对于单一体系，FdB1 和 FdR17 的最大吸附容量分别为 1508 和 1480mg/g；对于二元体系，FdB1 和 FdR17 的最大吸附容量分别为 955 和 902mg/g。热力学参数表明，吸附是自发、放热和有利的过程。最能代表动力学数据的模型是 Avrami 模型。在解吸中，吸附剂可以使用多达四次，并保持吸附剂 71%的初始容量的吸附能力。
