Belibagli Pınar, Isik Zelal, Dizge Nadir, Balakrishnan Deepanraj, Afzal Abdul Rahman, Akram Muhammad
Department of Energy Systems Engineering, Tarsus University, Tarsus, Turkey.
Department of Environmental Engineering, Mersin University, Mersin, Turkey.
PLoS One. 2024 Dec 31;19(12):e0309607. doi: 10.1371/journal.pone.0309607. eCollection 2024.
The reuse of electro-coagulated sludge as an adsorbent for Cr(VI) ion reduction was investigated in this study. Electro-coagulated sludge was obtained during the removal of citric acid wastewater by the electrocoagulation process. The following parameters were optimized for Cr(VI) reduction: pH (5-7), initial Cr(VI) concentration (10-50 mg/L), contact time (10-45 min), and adsorbent dosage (0.5-1.5 g/L). Cr(VI) reduction optimization reduction experimental sets were designed using response surface design. Cr(VI) reduction optimization results 97.0% removal efficiency and 15.1 mg/g adsorption capacity were obtained at pH 5.0, 1.5 g/L electro-coagulated Fe3O4 sludge, 10 mg/L initial Cr(VI) concentration and 45 min reaction time. According to the isotherm results, the experimental data are compatible with the Freundlich isotherm model, and since it is defined by the pseudo-second order model emphasizes that the driving forces of the Cr(VI) reduction process are rapid transfer of Cr(VI) to the adsorbent surface. The reusability of the adsorbent was investigated and Cr(VI) reduction was achieved at a high rate even in the 5th cycle. All these results clearly show that electro-coagulated Fe3O4 sludge is an effective, inexpensive adsorbent for Cr(VI) removal from wastewater.
本研究考察了电凝聚污泥作为吸附剂用于还原六价铬离子的可行性。电凝聚污泥是在电凝聚法处理柠檬酸废水过程中获得的。对六价铬还原的以下参数进行了优化：pH值（5 - 7）、初始六价铬浓度（10 - 50 mg/L）、接触时间（10 - 45分钟）和吸附剂用量（0.5 - 1.5 g/L）。采用响应面设计方法设计了六价铬还原优化实验装置。在pH值为5.0、电凝聚四氧化三铁污泥用量为1.5 g/L、初始六价铬浓度为10 mg/L和反应时间为45分钟的条件下，获得了六价铬还原优化结果，去除率达97.0%，吸附容量为15.1 mg/g。根据等温线结果，实验数据与弗伦德利希等温线模型相符，且由准二级模型可知，六价铬还原过程的驱动力是六价铬快速转移到吸附剂表面。考察了吸附剂的可重复使用性，即使在第5个循环中，六价铬仍能以较高速率被还原。所有这些结果清楚地表明，电凝聚四氧化三铁污泥是一种从废水中有效去除六价铬的廉价吸附剂。
