Rare earths elements and 87Sr/86Sr in groundwater landfill

A study was carried out to assess the water quality situation of groundwater in a municipal solid waste landfill of Central Italy. Landfill leachate is a serious problem for the groundwater contamination, because it contains a large amount of contaminants which are likely to pollute groundwater. In this study, beyond to determination of major ions and trace elements we have determined the concentrations of rare earths elements and Sr isotopes.This study was conducted also to investigate the use of different geochemical methods for evaluating the landfill impact in the area. The determination of major ions and trace element has show that there is a contamination of groundwater situated downgradient of the site. The principal contaminants are Cl, NH4 +, Fe, As, B, Hg and Cr. Furthermore, we have determined the concentrations of rare earths elements and the Sr isotopes in some piezometers around the landfill for studying the geochemical characteristics of the waters and to test the use of these elements as tracers of contamination. In recent years rare earths elements were used for many high technology products and processes resulted in an increase of interest for these elements. Some studies show an enrichment of these in river water of the big city, furthermore there is an evidence of their presence in municipal solid waste. We have analysed the REE concentrations in groundwater and one piezometer show a positive Gadolinium anomaly that could be due at landfill leachate. This is an important data because confirm the enrichment of REE in natural matrix in relation of human activity. 87Sr/86Sr isotopic ratio can be used as a tracer for understanding the lithological composition in which the groundwaters circulated and for the reconstruction of the potential areas of recharge for the aquifer levels. Sr isotope have been analysed for five water points. The results show that the values of 87Sr/86Sr range from 0.70895 to 0.70905, with a clear marine signature (0.70905-0.70910). Uncontaminated groundwater presents a value of 0.70905 while in contaminated piezometers the values lower (0.70895 in piezometer more contaminated).