The role of physico-chemical and biological processes in manganese and ammonia nitrogen removal from groundwater

This paper presents investigation results which evaluate the role of biolog ical processes in elimination of Mn (II) and NH4+ ions from groundwater. Th e raw water containing up to 1.4 mg/dm(3) manganese and up to 2.9 mg N/dm(3 ) ammonia nitrogen after aeration was treated using first and second stage sand filters at the "Letniki" water treatment plant near Elblag. Both ions were removed with high efficiency and the concentrations of these component s after two stages of filtration were lower than the admissible values for drinking water In Poland (0.1 mg Mn/dm(3) and 0.5 mg N-NH4/dm(3)). It was f ound that physico-chemical and biological processes were responsible for am monia nitrogen elimination, while catalytic processes (physico-chemical and biological) contributed to manganese removal.