Kordloo Mehrdad, Jafari Nima, Rezaei Ali, Noeparast Hanieh, Nasab Marzieh Hosseini, Ghorbani Yousef
School of Mining Engineering, College of Engineering, University of Tehran, Tehran, Iran.
School of Science, Western Sydney University, Richmond, NSW, Australia.
Sci Rep. 2026 Jan 31;16(1):6799. doi: 10.1038/s41598-026-37924-x.
Electroplating sludge (ES), a hazardous waste rich in toxic heavy metals, is produced through CaO/Ca(OH) precipitation. Despite its hazardous nature, the sludge is also a valuable secondary source of metals, making its recycling crucial both environmentally and economically. This study introduces an innovative ultrasonic-assisted ferric sulfate bio acid (FSBA) process to leaching of chromium (Cr), copper (Cu), and nickel (Ni) from ES. The bacterial supernatant of Acidithiobacillus ferrooxidans was employed to produce ferric ion and sulfuric acid for the ultrasonic-assisted leaching experiments. The impact of various parameters on the leaching efficiency in the presence of biogenic acids was systematically investigated. Ultrasonication significantly improved metal extraction rates and reduced the leaching time, achieving extraction efficiencies of 92.51% for Cr, 86.91% for Cu, and 91.25% for Ni within 8 min at an S/L ratio of 10 g/L, 400 rpm agitation speed, and 45 °C. Elemental analyses confirmed the enhanced metal extraction facilitated by ultrasonic. Furthermore, field emission scanning electron microscopy and X-ray diffraction analyses have detected the formation of hydronium jarosite on residue surfaces at 75 °C temperature. Finally, both the synthetic precipitation leaching procedure and toxicity characteristic leaching procedure tests demonstrated effective detoxification of the ES through FSBA.
电镀污泥（ES）是一种富含有毒重金属的危险废物，通过氧化钙/氢氧化钙沉淀产生。尽管具有危险性，但该污泥也是一种有价值的金属二次来源，因此其回收利用在环境和经济方面都至关重要。本研究引入了一种创新的超声辅助硫酸铁生物酸（FSBA）工艺，用于从电镀污泥中浸出铬（Cr）、铜（Cu）和镍（Ni）。利用氧化亚铁硫杆菌的细菌上清液产生铁离子和硫酸，用于超声辅助浸出实验。系统研究了各种参数对生物酸存在下浸出效率的影响。超声处理显著提高了金属提取率并缩短了浸出时间，在固液比为10 g/L、搅拌速度为400 rpm和温度为45°C的条件下，8分钟内铬的提取效率达到92.51%，铜为86.91%，镍为91.25%。元素分析证实了超声促进了金属提取。此外，场发射扫描电子显微镜和X射线衍射分析检测到在75°C温度下残渣表面形成了水合黄钾铁矾。最后，合成沉淀浸出程序和毒性特性浸出程序测试均表明，通过FSBA可有效实现电镀污泥的解毒。
