Denitritation of reject water using primary sludge as organic substrate

The new biological methods of separate reject water treatment became progressive tools to optimization of nutrient removal in wastewater treatment. The method of nitritation and denitritation is one of them. The drawback of the method in comparison with technologies based on autotrophic deammonification is higher requirements for organic substrate. The possibility to suppress the drawback is the use of primary sludge as internal carbon source for denitritation. The experience with such design of separate reject water treatment process is described. The presented results confirm the possibility of efficient, stable and economical removal of nitrogen from reject water by separate biological treatment using nitritation and denitritation process and using primary sludge as the additional carbon source.