INFILTRATION OF COMBINED SEWER OVERFLOW AND TERTIARY TREATED MUNICIPAL WASTEWATER : AN INTEGRATED LABORATORY AND FIELD STUDY ON VARIOUS METALS

Metal ion retention in infiltration processes. Filtration of sewer overflow and treated municipal wastewater is studied during 2 years with field and laboratory pilot units packed with soils. Analyses of heavy metal ions are performed in different waters before and after treatments. Metal removal is discussed as a function of operating conditions and mechanisms occurring in this complex system: nitrification, mineralization, acidification... carbonate mineral addition is recommended in order to neutralize acid formation and to get good soil retention.