Sequential Removal of Organic Substrate, Nitrogen and Phosphorus in Wastewater by an Apparatus Combining Activated Sludge Reactors with a Biofilm Reactor
1993 Volume 19 Issue 2 Pages 148-154
Details
1993 Volume 19 Issue 2 Pages 148-154
An apparatus combining activated sludge reactors with a biofilm reactor was used for sequential removal of organic substrate, nitrogen and phosphorus from wastewater. The biofilm reactor was used for nitrification of ammonium. Activated sludge-adsorbed and-absorbed organic substrate from wastewater in the first aeration tank was for the sequential removal of nitrogen and phosphorus.
In the batch operation, the highest removal rate of organic substrate was attained by activated sludge at four to five days aeration time after the addition of substrate, The iofilm nitrified ammonium in the case of COD values lower than 3.0×10-2kg/m3 in wastewater.
In continuous operation of the apparatus, the removal efficiencies of organic substrate, inorganic nitrogen and inorganic phosphorus were about 93, 75 and 45% respectively. Since the COD value in the influent to the biofilm tank was lower than 1.0×10-2kg/m3, no effect of nitrification of ammonium occurred. The substrate adsorbed and absorbed by the activated sludge in the first aeration tank could be used for denitrification and phosphate removal in the case of COD values higher than 4.0×10-2kg/m3 in the influent to the first tank.
