The Land Disposal of Wastes: A Study of Some Apulian Soils

The increasing interest in water reuse by land application of wastewaters and/or land disposal of solid wastes is posing much concern on underground water resources quality, and this calls for a deeper understanding of the physico-chemical interactive phenomena during percolation of the liquid-phase through the natural porous media (soil, subsoil). Among other processes responsible for attenuation (dispersion, retention, degradation) of a persistent chemical, in a fluid phase leaching along the flow path of a porous material, sorption and ion exchange phenomena play a relevant role in determining transport and availability of a pollutant substrate. After a review of the models available for predicting the fate and transport of contaminants in the subsurface environment the paper will furnish an example of application of lab-scale physico-chemical characterization of the natural porous material (solid-liquid interaction isotherms, cation exchange capacity, geochemical and pedological properties) to the solution of field problems. With reference to solid-waste landfill disposal, the paper assesses the transport of heavy metals such as Cr3+, Cd2+, Cu2+, Pb2+ on typical soils and subsoils of the Apulia region (S.E. Italy).