ENHANCED TREATMENT IN LAGOONS USING ADVANCED TECHNOLOGY LAGOON AERATION SYSTEM – INTERNAL SEPARATOR (ATLAS-IS)

To upgrade wastewater treatment lagoons to accomplish complete nitrification year-round and remove nitrogen through denitrification without recycle, Environmental Dynamics Inc (EDI) has developed the Advanced Technology Lagoon Aeration System – Internal Separator (ATLAS-IS™ system – patented process). The internal separator achieves retention and recirculation of biomass without the need for return activated sludge (RAS) pumping. The system operates at long sludge retention times (SRTs), resulting in excellent BOD removal and reliable nitrification. In a full-scale ATLAS-IS™ demonstration project at Ashland, Missouri, effluent containing BOD ≤ 15 mg/L, TSS ≤ 20 mg/L (with no tertiary solids control), and ammonia = ≤ 1.5 mg/L was obtained. Total nitrogen reduction was also observed, and effluent total nitrogen levels ≤ 15 mg/L appear achievable through the system. The ATLAS-IS™ system is an effective way to achieve these effluent quality targets with minimum additional capital expense and low operator attention typical of lagoons. The system can be installed online without interrupting treatment. This is therefore an ideal upgrade option for existing lagoons, especially in small communities where operator availability is a concern.