Heavy Metal Concentrations in a Soil Irrigated with Treated Municipal Wastewater: Mixed Effects Models to Analyse the Effect Over time

In arid and semi-arid regions of the world, non-conventional waters may represent an important complementary irrigation source. To investigate potential soil contaminations risks, repeated measurement experiments and rigorous methodological approaches may be adopted to assess variations of contaminant concentrations in the soil, eliminating possible confounding effects due to correlations over time.