Each water treatment facility comprised an aerobic nitrification biofilter, a deep-bed sand filter (Astral 750, Astralpool, Spain), and a denitrification biofilter that was connected in parallel to the main water flow.
Each watertreatment facility comprised an aerobic nitrification biofilter, adeep-bed sand filter (Astral 750, Astralpool, Spain), and adenitrification biofilter that was connected in parallel to the mainwater flow.