Sepúlveda Luisa A, Cuevas Fernando A, Contreras Elsa G
a Deparment of Chemical Engineering , Santiago de Chile University , Av. Libertador Bernardo O'Higgins 3363, Santiago , Chile.
Environ Technol. 2015 Jul-Aug;36(13-16):1913-23. doi: 10.1080/09593330.2015.1016119. Epub 2015 Mar 18.
The purpose of this work is to evaluate the valorization of agricultural waste, wheat straw (WS) and corn cob leaves (CCLs) as textile dye adsorbents. Physico-chemical and superficial characteristics of the agricultural wastes, together with the interactions with the CI Basic Violet 4 (BV4) dye, were investigated by means of the determination of the isotherm adsorption at different temperatures. The morphological characterization showed that the solid surface is coarse with a low pore level. However, through Fourier transformed infrared analysis, the presence of carboxylic and hydroxylic acid groups and hydrophobic methyl groups was detected. The concentration of acid groups is determined by the Boehm method and was found to be 1.00 and 0.89 meq/g for WS and CCLs, respectively. The point zero charge for each adsorbent was 5.76 and 4.08. Adsorption experimental data presented a better-fit Langmuir model, indicating that adsorption occurred in a monolayer with preferential interaction. The maximum adsorption capacity was determined to be 70.0-89.0 and 47.0-68.0 mg/g for CCLs and WS, respectively. The thermodynamic analysis of the Langmuir parameter b showed that the adsorption of the BV4 dye is spontaneous and exothermic with adsorption energies of 14.43 and 5.58 KJ/mol for CCLs and WS, respectively.
这项工作的目的是评估农业废弃物小麦秸秆（WS）和玉米芯叶（CCLs）作为纺织染料吸附剂的价值。通过测定不同温度下的等温吸附，研究了农业废弃物的物理化学和表面特性，以及与CI碱性紫4（BV4）染料的相互作用。形态表征表明，固体表面粗糙，孔隙率低。然而，通过傅里叶变换红外分析，检测到了羧基、羟基和疏水甲基的存在。采用Boehm法测定了酸性基团的浓度，发现WS和CCLs的酸性基团浓度分别为1.00和0.89 meq/g。每种吸附剂的零电荷点分别为5.76和4.08。吸附实验数据与Langmuir模型拟合较好，表明吸附以单层形式发生，且存在优先相互作用。CCLs和WS的最大吸附容量分别测定为70.0 - 89.0和47.0 - 68.0 mg/g。对Langmuir参数b的热力学分析表明，BV4染料的吸附是自发的且放热的，CCLs和WS的吸附能分别为14.43和5.58 KJ/mol。
