Hitit University.
Acta Chim Slov. 2022 Jun 14;69(2):336-348. doi: 10.17344/acsi.2021.7289.
The presence of dye molecules in water resources has harmful effects on environment. Therefore, it is important to remove dyes from wastewater using eco-friendly materials. In this study, adsorptive removal of diazo dye Direct Red 28 (DR-28) and tetra azo dye Direct Black 22 (DB-22) was investigated by using a new composite, kaolin supported zinc ferrite (KZF) as adsorbent. Characteristics of the composite, KZF were determined using various techniques such as FTIR, SEM, XRD, VSM, and EDS/Mapping. The adsorption of DR-28 and DB-22 on KZF was studied as a function of contact time, initial dye concentration, adsorbent amount, temperature, initial pH of the solution as well as the heat treatment of the composite. The removal of DR-28 was found to be 92.4% for the KZF concentration of 1g/200mL, initial dye concentration of 20 mg/L, contact time of 120 min at original pH and 21°C. On the other hand the removal of DB-22 was found to be 91.7% under the same conditions at 40 °C. The results showed that Langmuir isotherm is suitable for the adsorption of DR-28 and DB-22 on KZF under given conditions. It was found that adsorption of DR-28 on KZF was exothermic while that of DB-22 was endothermic. The enthalpy changes (ΔH0) for the adsorption of DR-28 and DB-22 dyes on KZF were found to be -24.59 kJ/mol and 61.95 kJ/mol respectively. ΔS0 for the adsorption of DR-28 dye was found to be negative while ΔS0 for the adsorption of DB-22 was positive. The kinetic data fitted well to the pseudo second order model for the adsorption of DR-28 and DB-22 on KZF composite. These results showed that the prepared adsorbent KZF could be used as an adsorbent for the efficient removal of anionic dyes.
染料分子在水资源中的存在对环境有有害影响。因此，使用环保材料从废水中去除染料非常重要。在这项研究中，使用新型复合材料高岭土负载锌铁氧体（KZF）作为吸附剂，研究了偶氮染料直接红 28（DR-28）和四氮染料直接黑 22（DB-22）的吸附去除。通过各种技术，如 FTIR、SEM、XRD、VSM 和 EDS/映射，确定了复合材料 KZF 的特性。研究了吸附剂 KZF 对 DR-28 和 DB-22 的吸附作用，考察了接触时间、初始染料浓度、吸附剂用量、温度、溶液初始 pH 值以及复合材料的热处理等因素对吸附的影响。结果表明，在 KZF 浓度为 1g/200mL、初始染料浓度为 20mg/L、接触时间为 120min、原始 pH 值和 21°C 的条件下，DR-28 的去除率为 92.4%。另一方面，在相同条件下，40°C 时 DB-22 的去除率为 91.7%。结果表明，在给定条件下，Langmuir 等温线适用于 KZF 对 DR-28 和 DB-22 的吸附。发现 DR-28 在 KZF 上的吸附是放热的，而 DB-22 的吸附是吸热的。KZF 对 DR-28 和 DB-22 染料吸附的焓变（ΔH0）分别为-24.59kJ/mol 和 61.95kJ/mol。发现 DR-28 染料吸附的ΔS0为负值，而 DB-22 染料吸附的ΔS0为正值。DR-28 和 DB-22 在 KZF 上的吸附动力学数据很好地符合准二级动力学模型。这些结果表明，制备的吸附剂 KZF 可用于有效去除阴离子染料。
