Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas, Departamento de Ingeniería Bioquímica, Unidad Profesional Adolfo López Mateos, Delegación Gustavo A. Madero, Ciudad de México, México.
Universidad Politécnica de Tlaxcala, Colonia San Pedro Xalcaltzinco, Tepeyanco, Tlaxcala, México.
PLoS One. 2018 Apr 26;13(4):e0196428. doi: 10.1371/journal.pone.0196428. eCollection 2018.
The corncob is an agricultural waste generated in huge quantities during corn processing. In this paper, we tested the capacity of corncob particles for water purification by removing the azo dye Direct Yellow 27 (DY27) via biosorption. The biosorption process was investigated in terms of the kinetics, equilibria, and thermodynamics. Batch biosorption studies showed that the biosorption performance has strong inverse correlations to the solution pH and the corncob particle size, and it increases quickly with increasing contact time and initial dye concentration. The pseudo-second-order kinetic model provides the best fit to the experimental data, whereas the Redlich-Peterson isotherm model is most suitable for describing the observed equilibrium biosorption. The biosorption process is exothermic, spontaneous, and physisorption in character. Fourier transform infrared (FTIR) spectroscopy and confocal scanning laser microscopy (CSLM) studies suggest that lignocellulose and proteins play key roles in the biosorption of DY27 from aqueous solutions by corncob. Furthermore, after biosorption onto the corncob, the dye can be effectively desorbed using 0.1 M NaOH solution. Therefore, the corncob can be used as a promising biosorbent to remediate DY27-contaminated water and wastewater.
玉米芯是玉米加工过程中产生的大量农业废弃物。在本文中，我们通过生物吸附法测试了玉米芯颗粒去除偶氮染料直接黄 27（DY27）的水净化能力。从动力学、平衡和热力学方面研究了生物吸附过程。批量生物吸附研究表明，生物吸附性能与溶液 pH 值和玉米芯颗粒尺寸呈强反比关系，且随着接触时间和初始染料浓度的增加而迅速增加。准二级动力学模型对实验数据拟合最好，而 Redlich-Peterson 等温模型最适合描述观察到的平衡生物吸附。生物吸附过程是放热的、自发的和物理吸附的。傅里叶变换红外（FTIR）光谱和共聚焦扫描激光显微镜（CSLM）研究表明，木质素纤维素和蛋白质在玉米芯从水溶液中吸附 DY27 方面发挥了关键作用。此外，用过的玉米芯吸附剂可以使用 0.1 M NaOH 溶液有效解吸染料。因此，玉米芯可以作为一种很有前途的生物吸附剂来修复 DY27 污染的水和废水。
