Bidiraa Firomsa, Bekele Endrias Adane, Muleta Werkne Sorsa
Faculty of Civil and Environmental Engineering, Jimma Institute of Technology, Jimma University, P.O. Box-378, Jimma, Ethiopia.
Faculty of Materials Science and Engineering, Jimma Institute of Technology, Jimma University, P.O. Box-378, Jimma, Ethiopia.
Heliyon. 2024 Oct 18;10(21):e39234. doi: 10.1016/j.heliyon.2024.e39234. eCollection 2024 Nov 15.
The presence of chromium (Cr) in synthetic wastewater has become a serious environmental issue. Therefore, main aim of this work was to investigate Cr removal from synthetic wastewater via electrocoagulation (EC) with a natural coagulant using aluminum electrodes. The central composite design (CCD) of the response surface methodology (RSM) method was used to optimized the operating variables of solution pH (5-9), initial Cr concentration (225-475 mgL), reaction time (30-40 min), and applied current (0.35-0.55 A). The ANOVA results clearly shows that the quadratic model (p < 0.0001) was sufficient to the best predicting of the removal performance of Cr (R = 0.9994 for electrode distance of 0.5 cm and 0.9924 for 1 cm). The maximum removal (99.836 % for electrode distance of 0.5 cm, and 98.175 % for 1 cm) of Cr was achieved with optimized conditions of solution pH 7.053, initial Cr concentration 337.795 mgL, reaction time 37.148 min, and applied current of 0.505 A. From this finding, it was proved that the EC process assisted with natural coagulant is an efficient, and cost-effective method for the removal of Cr from synthetic wastewater.
合成废水中铬（Cr）的存在已成为一个严重的环境问题。因此，本研究的主要目的是研究使用铝电极通过电凝聚（EC）和天然凝聚剂从合成废水中去除铬。采用响应面法（RSM）的中心复合设计（CCD）来优化溶液pH值（5 - 9）、初始铬浓度（225 - 475 mg/L）、反应时间（30 - 40分钟）和施加电流（0.35 - 0.55 A）等操作变量。方差分析结果清楚地表明，二次模型（p < 0.0001）足以最好地预测铬的去除性能（电极距离为0.5 cm时R = 0.9994，1 cm时R = 0.9924）。在溶液pH值7.053、初始铬浓度337.795 mg/L、反应时间37.148分钟和施加电流0.505 A的优化条件下，实现了铬的最大去除率（电极距离为0.5 cm时为99.836%，1 cm时为98.175%）。从这一发现证明，天然凝聚剂辅助的电凝聚过程是一种从合成废水中去除铬的高效且经济有效的方法。
