M. Patel, A. Karamalidis
Penn State University,
Keywords: solid-phase extraction, germanium, functionalized adsorbents
Summary:In the current study, novel diphenol-based functionalized adsorbers are developed for selective solid-phase extraction of germanium. Germanium is a critical element because of its growing demand, supply risk, and inefficient production. Conventional productions based on chlorination-distillation and solvent extraction suffer from high energy requirements, high chemicals consumption, impurities co-extractions, and waste stream generation. The adsorbents were characterized by FTIR, NMR, XPS, and SEM. pH edge and adsorption isotherm were used to study the behavior of the adsorbent. Desorption and regeneration cycles were carried out to estimate the recovery of germanium and the stability of the adsorbent. Adsorption of Ge from actual samples such as Zn refinery residue and coal fly ash was carried out. The novel diphenol functionalized adsorbents selectively adsorbed Ge from multielement solutions. Initial tests showed Kd values exceeding 12,000 mL/g for the novel adsorbents favoring Ge separation over other ions in solution compared to commercial adsorbents.