Large scale physical model experiments to improve water quality using soil-aquifer-treatment (SAT-MAR)

Abstract

The use of Soil-Aquifer Treatment (SAT) systems to improve the effluents water quality during the transport of infiltrated water through the unsaturated and saturated zones canbe a solution for water reclamation, water reuse, and overall as a water resources management tool. This abstract presents the results of theresearch carried out under MARSOL project were SAT experiments were executed in a physical (sandbox) model. These experiments aimed to contribute solving the problem of removing rice field contaminants from water, using a soil-aquifer prototype basin to treat water prior to its discharge in Melides lagoon, Portugal. The sandbox model was divided into three sections to test the adsorption anddegradation capacity of three soil profiles, two of them including soil mixtures of sand with vegetal compost with different layouts. In each section, two tracer experiments were performed with spiked fertilizer and hydrocarbons. To analyse the tracers behaviour, monitoring devices were installed in three piezometers for continuous in situ readings of pH, temperature (T), electrical conductivity (EC), redox potential (ORP)and water level, besides water sampling hand-pump for chemical analysis. The resultsobtained in the experiments gave useful knowledge necessary to build an in situfacility.