Optimization of the Alternate Cycling Process for Nutrient Removal in Industrial Wastewater Treatment Plants – Full Scale Study

One of the current concerns in the field of wastewater treatment is how to meet new targets of effluent nitrogen limits in a cost effective manner. The application of oxic and anoxic cycles in a wastewater treatment bioreactor is an effective way of enabling a COD removal plant to meet Biological Nitrogen Removal goals. When alternating oxic-anoxic cycling schemes are combined with the use of High Purity Oxygen, the biological process becomes a compact and powerful solution for high strength industrial wastewater treatment. This paper presents the results obtained at a full scale industrial facility after upgrading it for total nitrogen removal using the Alternating Cycles (AC) scheme. The AC process has been optimized to obtain the required effluent limits at minimum operational costs. An online sensor for NH4-N and NO3-N concentration measurement has been applied to the full scale facility to monitor its performance. Model based simulation tools have been used to design the required cyclic pattern and to evaluate an automatic control loop that has also been applied in the real facility and successfully validated. The demonstration of the technical and economic effectiveness of the AC process in a full-scale WWTP implies that it can be a cost effective solution for plant retrofits in order to reach nutrient removal targets.