Homogeneous Liquid-Liquid Extraction (HoLLE) of Palladium in Real Plating Wastewater for Recovery

Abstract

On the basis of homogeneous liquid-liquid extraction (HoLLE) with Zonyl FSA to plating water containing 1 mg palladium, 96.6% of the palladium was extracted into the sedimented liquid phase. After phase separation, the volume ratio (Va/Vs) of the aqueous phase (Va) and the sedimented liquid phase (Vs) was 556 (50 mL → 0.09 mL). The assessment of the potential implementation of this procedure to wastewater treatment showed that HoLLE was satisfactorily achieved when the volume was scaled up to 1000 mL. Moreover, HoLLE was conducted to real palladium plating wastewater generated in the plating industry. 94.5% of the palladium was extracted into the sedimented liquid phase. After phase separation, the volume ratio (Va/Vs) of the aqueous phase (Va) and the sedimented liquid phase (Vs) was 500 (50 mL → 0.1 mL). In addition, HoLLE could separate palladium from coexisting metals in real plating wastewater. This knowledge is expected to lead to the development of new separation and concentration technologies of rare metals from real plating wastewater.

Rapid Determination of Sub-ppm Heavy Metals in the Solution State via Portable X-ray Fluorescence Spectrometry Based on Homogeneous Liquid-Liquid Extraction in a Ternary Component System

“…HoLLE can rapidly achieve high concentration rates down to very low sample volumes. [17][18][19][20][21] The HoLLE procedure is easy to operate and requires only the addition of a solution. Using a homogeneous solution before HoLLE leads to a highefficiency phase separation.…”

Historical and current usage of per‐ and polyfluoroalkyl substances (PFAS): A literature review

“…Indium can be recovered from liquid crystal displays using PFAS in homogeneous liquid–liquid extraction (HoLLe) during recycling 266 . The HoLLe process with PFAS has also been investigated for recovery of platinum group metals from plating wastewater 267,268 …”

“…266 The HoLLe process with PFAS has also been investigated for recovery of platinum group metals from plating wastewater. 267,268 Supercritical carbon dioxide with PFAS surfactants have been investigated to remove radioactive cesium from contaminated soil. In the research, high extraction percentages were achieved from soil and sand.…”

Powerful Concentration of Rhodium in Plating Wastewater Using Homogeneous Liquid–Liquid Extraction (HoLLE) and Study for Scale-up

“…In HoLLE, the target solute is concentrated into a small secondary phase through the effect of some stimulation such as pH, or light. HoLLE has been widely used to extract target solutes such as indium (In) (Kato, Igarashi, Ishiwatari, Furukawa, & Yamaguchi, 2013), cobalt (Co) (Kato, Igarashi, Saito, Ando, & Asano, 2014), rare earth elements (Saito, Ohno, Igarashi, Kato, & Yamaguchi, 2015), and Pd (Kato, Igarashi, Ohno, Saito, & Ando, 2016), although the target solute is not limited to metals. Additionally, HoLLE can be applied to organic compounds (Takagai & Igarashi, 2002) and biological materials (Sudo & Igarashi, 1996).…”