Simultaneous denitrification with nitrification in single-channel oxidation ditches

Biological processes for denitrification with nitrification are becoming increasingly important for wastewater treatment. The addition of denitrification to a nitrification process can have several advantages over nitrification alone: complete nitrogen removal; enhanced phosphorous removal; reduced aeration requirement, which saves energy costs and increases the capacity of an overloaded facility, thus eliminating costs for expansion; and reduced alkalinity consumption. The third of these advantages, reduced aeration requirements, has the most widespread interest. Only a few facilities are required to remove nitrogen or phosphorous, and alkalinity consumption is not a serious concern in locations where alkalinity is high. On the other hand, everyone is interested in saving money. If the advantages of denitrification with nitrifi cation are to be available at as many treatment facilities as possible, the process design and operation need to be simple. The results of this study document the successful performance of a simple process for denitrification with nitrification: simul taneous, one-sludge denitrification with nitrification in single channel oxidation ditches.