ETL

• - Ammonical Nitrogen was a major problem in the inlet to the CETP, average as high as 1000 mg/l
• - As part of CEPI Action Plan, effluent segregated and treatability studies conducted
• - MAP Process developed and implemented
• - Magnesium Ammonium Phosphate is insoluble and can be used as soil conditioner
• - After implementation of MAP Process, the biological performance also improved

Limitations of old system:

• - High biological solids retention time and hydraulic retention time, more foot print
• - Nitrifiers are highly sensitive to the random fluctuations in the input effluent parameters typically received at ETL. This requires more sewage for dilution and organic load equilibration
• - Since two aeration tanks are in parallel, separate bio-augmentation process could not be employed in two aeration tanks, i.e. separate cultures for COD removal and Nitrification -Denitrification
• - Organic loading rates (OLR) is limited to 0.1-0.4 and F/M range is limited to 0.05-0.2. In comparison, for the proposed high rate ASP, the OLR is 0.45-2 and F/M ranges from 0.2-0.6
• - High sewage requirement to maintain TDS

• - In this two-stage process, the COD and BOD will be removed in the first stage while in the second stage, some refractory COD and ammonia will be removed.
• - MLE (Modified Ludzak Ettinger) process consisting of a combination of Anoxic and Aerobic reactors, some refractory COD and remaining ammonia nitrogen will be treated.
• - MAP Process developed and implemented
• - In MLE (Modified Ludzak Ettinger) process, nitrogen is removed by a combination of nitrification and denitrification, total nitrogen load in the effluent will go down significantly as the nitrate (product of nitrification) will be converted to gaseous nitrogen and recycled back to the atmosphere.