Analysis of traces of precious metals in soils

点击翻译按钮获取中文摘要

Platinum group metals (PGMs) are used as active elements in car catalytic converters. Mainly highly dispersed platinum (Pt), palladium (Pd), and rhodium (Rh) nanoparticles (NPs) on ceramic support materials are applied and are partly emitted with the exhaust due to thermal and mechanic abrasion. Up to some 100 ng PGMs per kilometre can be emitted mainly as particular matter. Up to a third of the weight of these particles are smaller than 5 nm in size. The emitted particles settle beside roads and are infiltrated in so far unknown manner in roadside soils. The aim of the proposed project is to evaluate the transport and accumulation of PGM in soils. Thereby, it will be investigated in what depths the PGMs are transported in topsoil, in which soil types and layers they are accumulated and whether infiltration into ground water is to be estimated. Several samples from infiltration basins along roads with different traffic densities will be taken and Pd, Pt, and Rh concentrations will be determined in different soil depth. For this purpose a flow injection analysis system for pre-concentration of Pd traces will be further developed in order to analysis traces of Pt and Rh. This new method will be optimized and validated. The results of this projects will contribute to the risk assessment of PGM-NPs in the environment in general.