| Summary: | Poster.-- Advanced Workshop on Solution Chemistry of TCEs, Byalystok, 22-23 Januery 2019 Platinum (Pt) is amongst the least abundant elements in the Earth’s crust, with average concentrations around or below the nanogram per gram level. However, its distribution in several environmental compartments is undergoing a significant transformation due to the considerable increase in its anthropogenic emissions over the last three decades mainly due to its use in automotive catalytic converters. During abrasion and aging of washcoat layer of the catalyst, metallic and oxide forms of Pt are emitted as particles (normally 10-30 μm) at rates up to several hundred nanogram per kilogram per vehicle [1] and then are subject to mobilization through interaction/complexation with naturally occurring ligands [2]. Accordingly, Pt concentrations well above background values have been reported in areas subject to vehicular traffic and also evidence for a long range transport and contamination has been given from the study of Greenland and Antarctic ice cores [3,4]. In this context, rivers, estuaries and coastal areas are subject to increasing Pt anthropogenic inputs. Their solution speciation and geochemistry is, therefore, much required in order to study and predict its biogeochemical behaviour (reactivity, transport, fate, toxicity). To this end, thermodynamic and kinetic models that accurately describe its interactions in the environmental compartments are needed. The solution speciation of Pt in natural waters has been, however, poorly characterised, and the available speciation calculations given in the literature are not fully consistent. The main characteristics of the information available on the geochemistry and speciation of Pt are the following: (i) stability constants with some inorganic ligands are still unknown; (ii) thermodynamic data has been derived from experiments using Pt concentrations well above ambient values. The extremely low concentrations of these elements hamper the study of their complexation at their ...
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