Department of Chemical Engineering, University of Technology, Baghdad, Iraq E-mail:
Department of Physics, Taibah University, Madinah, Saudi Arabia.
Water Sci Technol. 2021 Mar;83(6):1369-1383. doi: 10.2166/wst.2021.078.
In the present work, Zeolite A was modified by using hexadecyltrimethylammonium bromide (HDTMABr) for adsorption of the Congo red (CR) dye from synthetic aqueous solutions. The Modified Zeolite A (MZA) was characterized by XRD, SEM, and FTIR. The influence of solution pH (in the 4-12 range), ionic strength (0.1-1 M), contact time (180 min), initial CR concentration (20-60 mg/L), temperature (24-36 °C), and an adsorbent dose (1-3 g m/L) on the % dye removal and adsorbent capacity were studied. A combined effect of the initial CR concentration and temperature on the CR removal % by MZA was also studied by applying response surface methodology (RSM). Experimental values were in a good agreement with those predicated by a second-order quartic model. A maximum of 99.24% dye removal and adsorbent capacity of 21.11 mg/g was achieved under the following conditions: pH = 7, initial CR concentration = 60 mg/L, temperature = 24 °C, ionic strength = 0.1 M, adsorbent dose = 3 g/L and 90 min contact time. The equilibrium data were subjected to the Langmuir, Freundlich and Temkin isotherms, with the latter providing the best fit while kinetic adsorption studies were conducted by applying three models. The results indicated that the removal process was best described by the pseudo-second-order model. The present study demonstrates that modified MZA can be utilized for the highly efficient CR dye removal.
在本工作中，采用十六烷基三甲基溴化铵（HDTMABr）对沸石 A 进行改性，用于从合成水溶液中吸附刚果红（CR）染料。改性沸石 A（MZA）采用 XRD、SEM 和 FTIR 进行了表征。考察了溶液 pH 值（4-12 范围）、离子强度（0.1-1 M）、接触时间（180 min）、初始 CR 浓度（20-60 mg/L）、温度（24-36°C）和吸附剂用量（1-3 g/m3）对染料去除率和吸附剂容量的影响。还通过响应面法（RSM）研究了初始 CR 浓度和温度对 MZA 去除 CR %的综合影响。实验值与二次四次模型预测值吻合良好。在以下条件下，染料去除率最高可达 99.24%，吸附剂容量可达 21.11 mg/g：pH = 7，初始 CR 浓度= 60 mg/L，温度= 24°C，离子强度= 0.1 M，吸附剂用量= 3 g/L 和 90 min 接触时间。将平衡数据进行了 Langmuir、Freundlich 和 Temkin 等温线拟合，其中后者拟合度最好，同时通过应用三种模型进行了动力学吸附研究。结果表明，去除过程最符合拟二级动力学模型。本研究表明，改性 MZA 可用于高效去除 CR 染料。
