Removal of cytostatic platinum compounds and recovery of precious metal from aqueous wastestream

Over the last decades, a strong antropogenic increase in platinum concentrations in the environment is observed. While catalytic converters used in cars and industry contribute to elevated levels in vegetation and soils, hospitals intensely discard platinum from their effluents to surface waters. Since the discovery of its cytostatic properties by Rosenberg, cisplatin and other platinum coordinating compounds such as carboplatin and more recently oxaliplatin are extensively used in chemotherapy for cancer treatment. After ingestion and interaction with DNA, the drugs are biodegraded and excreted by patients through urine – either in hospital or at home - to remain mostly untreated. Biomaterials are ubiquitous distributed over the world and ready available with equal performance. They show a promising potential as sorbent for pollutants from wastewaters. The precious metal containing material can be separated from solution as a solid and be processed and valorised afterwards. In a screening step, several natural wood-based materials and dried microalgal biological flocs have been tested for their sorption efficiency towards cytostatic platinum compounds

Speciation-analysis for recycling of critical elements in aqueous waste streams

Limited availability of inorganic commodities is one of the largest challenges for a future sustainable material use as set by European Commission. Growing life standards, demand for mobility and electronic devices require more and more specialty materials. Combining this economic importance and their supply risk, a class of critical materials is defined. PGM’s include Pt, Rh, Pd, Ir, Ru and Os. They possess unique properties, making them indispensable in autocatalysts, jewelry, electrical and electronical applications and industrial catalysts. PGM prices, with Pt being the far most important, have seriously risen in the last years. REE’s comprehend 17 elements with a large chemical similarity, essential in i.a. permanent magnets and related ‘clean energy’ applications such as wind turbines, rechargeable batteries and electric vehicles. Tight export quota set by the world’s largest exporting country of REE’s, China, hardly meet this rising demand

Selective metal extraction by biologically produced siderophores during bioleaching from low-grade primary and secondary mineral resources

Siderophores are a class of biogenic macromolecules that have high affinities for metals in the environment, thus could be exploited for alternate sustainable metal recovery technologies. Here, we assess the role of siderophores in the extraction and complexation of metals from an iron oxide-rich metallurgical processing residue and a low-grade primary Ni ore. Evaluation of the biological siderophore production by three pseudomonads, P. fluorescens, P. azotoformans and P. putida identified that P. putida could generate the highest siderophore yield, which was characterized as a hydroxamate and catecholate mixed-type pyoverdine PyoPpC-3B. Key physicochemical parameters involved in raw siderophore mediated metal extraction were identified using a fractional factorial design of experiments (DOE) and subsequently employed in purified PyoPpC-3B leaching experiments. Further targeted experiments with hydroxamate and catecholate functional analogues of PyoPpC-3B confirmed their marked ability to competitively or selectively leach and chelate hard metal ions, including Al(OH)(4)(-), Mn2+ and Zn2+. Interestingly, complexation of Mn and Zn ions exceeded the natural affinity of pyoverdine for Fe3+, thus despite the low metal recoveries from the materials tested in this study, this work provides important new insights in siderophore-metal interactions