Management optimisation of a large wastewater treatment plant

The present study gives a useful way to optimize the operating (i.e. improving efficiency and saving energy) of a large wastewater treatment plant. The methodology was developed at the nitrogen removing activated sludge plant of “Roma-Est” (800,000 p.e.). Once design and operating data had been collected, a five-month experimentation was conducted to characterise the influent wastewater substrate fractions and to calculate the main kinetic parameters of the biomass. All data were used as parameters for a modified version of the ASM n.1 mathematical model, simulating the biological process flow, organic load and temperature variations as well as plant scheme modifications. Simulations showed the possibility of shutting down one of the three treatment lines and overloading the other two, with great operating improvement. Besides, neither the use of primary sedimentation, nor the aerated sludge internal recycle seem to be convenient.