Fig. 1

Simplified scheme of the pilot SAT system. The three SAT systems with different barrier compositions studied in the present work are represented. Color pink codes for the SAT without reactive barrier filled only with sand, color orange codes for the SAT with a reactive barrier made of sand (49%), compost (49), and clay (2%), and color blue codes for the SAT with a reactive barrier made of sand (49%), woodchips (49), and clay (2%). Samples were taken prior WWTP treatment (PRIM), after WWTP at the effluent reservoir (SEC), after the immediate passage through the reactive barrier (A), and at the very end of the systems (C). Water samples were collected in two different campaigns, June and October 2020 (further referred as JUN20, and OCT20, respectively), through a recharge period with a continuous allocated inflow and a recharge period with a pulsating allocated inflow, respectively.