Department of Chemical Engineering, Canal High Institute for Engineering and Technology in Suez, Egypt.
Department of Basic Science and Engineering, Higher Institute for Engineering and Technology. Manzala, Egypt.
Int J Phytoremediation. 2024;26(5):669-683. doi: 10.1080/15226514.2023.2259999. Epub 2023 Sep 22.
The aim of work is the use of a cheap adsorbent; sawdust (SD), for the adsorption of anionic dye, acid red57 (AR57), and cationic dye, basic fuchsin (BF). The adsorption of AR57 and BF on SD increased by increasing contact time and adsorbent dosage, while decreased with the increase of temperature and initial dye concentration. The increase in pH decreased the adsorption of AR57 and increased the adsorption of BF. The effective pH, adsorbent dose, and contact time on the AR57 removal efficiency were found to be 3, 0.1 g and 50 min, respectively. While for BF it was found to be 6, 0.2 g and 50 min, respectively. Fitting equilibrium data to Langmuir, Freundlich and Temkin isotherms showed that Freundlich model is the most suitable to describe the acid red57 and basic fuchsin. The kinetic studies indicate that the adsorption of AR57 and BF follows a pseudo-second-order model. The adsorption of both AR57 and BF is spontaneous (ΔG = -3.97, -3.27 kJ/mol) and exothermic (ΔH = -22.9, -8.3 kJ/mol) with negative values of ΔG and ΔH. The negative values of ΔS of both AR57 and BF (ΔS = -64.6, -16.7 J/mol. K) showed that the randomness decreases through the adsorption process.
这项工作的目的是利用廉价的吸附剂——木屑（SD）来吸附阴离子染料酸性红 57（AR57）和阳离子染料碱性品红（BF）。AR57 和 BF 在 SD 上的吸附量随接触时间和吸附剂用量的增加而增加，随温度和初始染料浓度的增加而降低。pH 值的增加降低了 AR57 的吸附量，增加了 BF 的吸附量。AR57 去除效率的有效 pH 值、吸附剂用量和接触时间分别为 3、0.1g 和 50min。而 BF 的则分别为 6、0.2g 和 50min。将平衡数据拟合到 Langmuir、Freundlich 和 Temkin 等温线上表明，Freundlich 模型最适合描述酸性红 57 和碱性品红。动力学研究表明，AR57 和 BF 的吸附符合准二级模型。AR57 和 BF 的吸附都是自发的（ΔG=-3.97、-3.27kJ/mol）和放热的（ΔH=-22.9、-8.3kJ/mol），ΔG 和 ΔH 的值为负。AR57 和 BF 的负ΔS 值（ΔS=-64.6、-16.7J/mol·K）表明吸附过程中无序度降低。
