Stainless steel pickling sludge (SSPS) is a noxious solid waste containing heavy metals (Fe, Cr, Mn, and Ni). Herein, an ultrafast ultrasonic-assisted leaching (UAL) extraction method for heavy metals from SSPS is proposed. The effects of key leaching factors, including acid lixiviant, acid dosage, leaching time, liquid-to-solid ratio, and leaching temperature, on the leaching efficiency of Fe, Cr, Ni and Mn in SSPS were systematically studied, followed by the theoretical optimization by response surface methodology. The leaching efficiencies of Fe, Mn, Ni, and Cr were significantly enhanced to 98.6%, 90.74%, 90.83%, and 92.25% within 15 min, which were nearly nine times higher than the acid leaching process. The ultrasonic burst broke up the SSPS and increased the contact area (mass transfer effect) of the heavy metal leaching reaction. In addition, kinetic and thermodynamic studies shown that sonochemical action could significantly promote the initial leaching efficiency of heavy metals. This work provided a super-fast method to recovery of heavy metal from SSPS, which shows great potential for the actual application.

中文翻译：

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声化学空化强化去除不锈钢酸洗污泥中的重金属：物理破碎和化学活化

不锈钢酸洗污泥（SSPS）是一种含有重金属（铁、铬、锰和镍）的有毒固体废物。在此，提出了一种从 SSPS 中提取重金属的超快超声辅助浸出 (UAL) 方法。系统研究了酸浸剂、酸用量、浸出时间、液固比、浸出温度等关键浸出因素对SSPS中Fe、Cr、Ni、Mn浸出效率的影响，并建立了理论模型。通过响应面法进行优化。 Fe、Mn、Ni、Cr的浸出率在15 min内显着提高至98.6%、90.74%、90.83%和92.25%，比酸浸工艺提高了近9倍。超声波爆发破坏了SSPS并增加了重金属浸出反应的接触面积（传质效应）。此外，动力学和热力学研究表明，声化学作用可以显着提高重金属的初始浸出效率。这项工作为从SSPS中回收重金属提供了一种超快速的方法，具有巨大的实际应用潜力。