Germanium(IV) Adsorption from Aqueous Solution Using a Kelex-100 Functional Adsorbent

Roadmap for recycling of germanium from various resources: reviews on recent developments and feasibility views

Germanium as a strategic metalloid is widely used in high-tech devices. The most crucial germanium resources are rare and limited to zinc minerals, i.e., especially zinc sulfides and coal-related products. Other than coals and zinc minerals, materials such as WEEEs (wastes from electrical and electronic equipment) and catalysts are considered secondary resources of germanium. Since there is no specific mineral for germanium, it should be extracted from the resources above as a by-product. Primary resources contribute to 70% of germanium production, whereas the rest is produced from recycled materials. The world refinery production of germanium enhanced by about 7% in 2020 compared to 2019. This growing demand for germanium encourages the industry to find other resources and extraction technologies. Germanium can be recovered after leaching of different resources in acidic, water, or alkaline media followed by processing using various hydro/pyrometallurgical methods. Several reviews and articles have been published to review the resources and processes for the germanium separation. However, no one did not present a final road map from feasibility views and environmental aspects. This review proposes a road map for germanium recycling based on the performance and economic availability, process efficiency, operational issues, and process feasibility.

Investigations on Strategic Element Recovery by an Underground Membrane Pilot Plant from In-Situ Extracted Bioleaching Solutions

Focusing on the selective extraction of the critical raw materials indium and germanium from real bioleaching solutions, extended studies have been carried out using Europe’s first underground hybrid membrane pilot plant (TRL6). In order to transfer former laboratory experiments to pilot scale, NF99 (Alfa Laval) was used for the evaluation of membrane permeance and ion retention. A performance test of microfiltration (MF) and nanofiltration (NF) showed high permeances with low root-mean-square deviation under feed variation (5.2% for MF, 4.7% for NF). Depending on the feed load, a significant permeance drop of up to 57% for MF (3 bar) and 26% for NF (10 bar, 1.1 m s−1) was observed. The NF retention performance showed that, without regular chemical cleaning, the selectivity between the target elements degraded. By introducing acidic-basic cleaning steps, it was possible to keep the retention behavior at an approximately constant level (In 91.0 ± 1.3%; Ge 18.2 ± 5.5%). In relation to the specified target, the best results could be achieved at low pressure (7.5 bar) and a maximum overflow velocity of 1.1 m s−1, with a retention of 88.4% for indium and 8.8% for germanium. Moreover, the investigations proved the functionality and long-term stability of the underground membrane device.

PET radiometals for antibody labeling

Recent advances in molecular characterization of tumors have made possible the emergence of new types of cancer therapies where traditional cytotoxic drugs and nonspecific chemotherapy can be complemented with targeted molecular therapies. One of the main revolutionary treatments is the use of monoclonal antibodies (mAbs) that selectively target the disseminated tumor cells while sparing normal tissues. mAbs and related therapeutics can be efficiently radiolabeled with a wide range of radionuclides to facilitate preclinical and clinical studies. Non-invasive molecular imaging techniques, such as Positron Emission Tomography (PET), using radiolabeled mAbs provide useful information on the whole-body distribution of the biomolecules, which may enable patient stratification, diagnosis, selection of targeted therapies, evaluation of treatment response, and prediction of dose limiting tissue and adverse effects. In addition, when mAbs are labeled with therapeutic radionuclides, the combination of immunological and radiobiological cytotoxicity may result in enhanced treatment efficacy. The pharmacokinetic profile of antibodies demands the use of long half-life isotopes for longitudinal scrutiny of mAb biodistribution and precludes the use of well-stablished short half-life isotopes. Herein, we review the most promising PET radiometals with chemical and physical characteristics that make the appealing for mAb labeling, highlighting those with theranostic radioisotopes.

Intrinsically germanium-69-labeled iron oxide nanoparticles: synthesis and in-vivo dual-modality PET/MR imaging

Intrinsically germanium-69-labeled super-paramagnetic iron oxide nanoparticles are synthesized via a newly developed, fast and highly specific chelator-free approach. The biodistribution pattern and the feasibility of (69) Ge-SPION@PEG for in vivo dual-modality positron emission tomography/magnetic resonance (PET/MR) imaging and lymph-node mapping are investigated, which represents the first example of the successful utilization of a (69) Ge-based agent for PET/MR imaging.