Chen Lih-Fu, Wang Hsiou-Hsuan, Lin Kao-Yung, Kuo Jui-Yen, Wang Ming-Kuang, Liu Cheng-Chung
College of Liberal Education, Shu-Te University, Kaohsiung 82445, Taiwan.
Department of Materials Engineering, National Ilan University, Ilan 260, Taiwan.
Water Sci Technol. 2018 Sep;78(3-4):556-570. doi: 10.2166/wst.2018.326.
Drainage canal sediments in an industrial park are generally dredged to landfill in Taiwan. The objective of this study was to evaluate feasibility employing the sediment as an adsorbent for removal of dye. The sediment contained approximately 10% of organic matter and little heavy metals. Infrared (IR) analysis revealed that carboxyl was the most important functional group for methylene blue (MB) sorption. Canal sediment could remove the most MB from water at pH 8.0 and this removal increased with increasing temperature. The MB sorption was well described by the Langmuir, Dubinin-Radushkevich, and Temkin sorption isotherms at 10°C, but it showed good compliance with Freundlich isotherm at 25°C and 40°C. The MB adsorption was a spontaneous and endothermic reaction; its maximum calculated adsorption capacity (Q) was 56.0 mg g at 10°C by the Langmuir isotherm. The calculated values of enthalpy (ΔH°) and entropy (ΔS°) are 14.6 kJ mol and 149.2 kJ mol, respectively. Only pseudo-second-order adsorption kinetic model successfully described the kinetics of MB onto the sediment at different operation parameters. Activation energy of MB adsorption calculated from Arrhenius equation was 16.434 kJ mol, indicating the binding between canal sediment and MB was a physical adsorption.
在台湾，工业园区的排水渠沉积物通常被疏浚后填埋。本研究的目的是评估将该沉积物用作去除染料的吸附剂的可行性。该沉积物含有约10%的有机物，重金属含量很少。红外（IR）分析表明，羧基是亚甲基蓝（MB）吸附最重要的官能团。排水渠沉积物在pH 8.0时能从水中去除最多的MB，且这种去除量随温度升高而增加。在10°C时，MB的吸附符合朗缪尔、杜比宁-拉杜舍维奇和坦金吸附等温线，但在25°C和40°C时与弗伦德利希等温线拟合良好。MB的吸附是一个自发的吸热反应；根据朗缪尔等温线，在10°C时其最大计算吸附容量（Q）为56.0 mg/g。焓（ΔH°）和熵（ΔS°）的计算值分别为14.6 kJ/mol和149.2 kJ/mol。只有准二级吸附动力学模型成功描述了在不同操作参数下MB在沉积物上的吸附动力学。根据阿伦尼乌斯方程计算的MB吸附活化能为16.434 kJ/mol，表明排水渠沉积物与MB之间的结合是物理吸附。
