Combination of Vortex Agitation and Ultrasonic Irradiation for Mercury Removal from Sediment by Acid Extraction

The removal of Hg from solid waste plays a key role in environmental protection. In this study, a fast, simple, and effective method for the removal of Hg by acid extraction, using a combination of vortex agitation and ultrasonic irradiation along with hydrobromic acid (HBr), was established using Hg-containing solid wastes. The optimal durations of vortex agitation and ultrasonic irradiation with 48% v/v of HBr were 5 and 6 min, respectively, and total Hg (T-Hg) extraction was achieved within 21 min. The proposed method was validated using the Certified Reference Material (CRM) ERM CC580 (estuarine sediment) and CRM NMIJ 7302-a (marine sediment). Under the optimized conditions, the efficiency rates of T-Hg extraction in both CRMs were 99.5% and 94.2%, with repeatabilities of 3.21% RSD and 2.31% RSD, respectively. The proposed extraction method can also be used for the remediation of Hg in other environmental matrices.