An heterotrophic autotrophic denitrification approach for nitrate removal from drinking water by alfa stems

Abstract

Biological denitrification of drinking water was studiedin up-flow laboratory reactors packed with alfa stems served as the sole carbon source as well as the only physical support for the microorganisms. The highest rates of denitrification were observed in fresh reactors during their first week of operation and the efficiency of the process declined therafter. In the first part, we have analysed the influence ohhydrolyc and volumic load to value the capacity of nitrate prurification in a down flow submerged biofilter then with an experimental design approach, we have analysed the qualitative and quantita-tive aspects of the effects of some factors, concentration of nitrate (80-200 mgl-1 and velocity (0.31 mh-1 on different responses like the apparentrate of denitrification as well as concentration of nitrite, nitrate and chemical demand on oxygen (DCO)in the reactor outlet.