06 Mar 2015

Using WEST to access operational strategies for wastewater treatment plant in Spain

To help Arenales del Sol wastewater treatment plant (WWTP) select the ideal start-up procedure among a variety of possible operation modes, we developed a calibrated model using WEST – our tool of choice for dynamic modelling and simulation of WWTPs and other types of water quality related systems.

The coastal region of Alicante, Spain, is a popular destination for visitors during the summer and winter touristic seasons. It is therefore essential that its WWTP – Arenales del Sol – is equipped with the capability to provide high quality treatment to greatly variable seasonal sewage inflow.

One of the challenges that Arenales del Sol WWTP faced was having a suitable seeding procedure which could reduce the start-up time for its large membrane bioreactor (MBR) system. To address that, we simulated the start-up phase of a flat-sheet MBR system of the WWTP using WEST. The simulation proved the effectiveness of our proposed solution – dosing molasses from a nearby candy factory to dramatically shorten the period needed to attain the optimal mixed liquor suspended solids (MLSS) concentration.

Overall, the WEST model aptly predicted the MLSS evolution and the biologic removal of organic matter and nitrogen in the MBR. The model can be applied in operational strategy studies to reduce energy consumption for aeration without compromising effluent quality. It can also be useful when compiling an operations and maintenance manual for a wide range of process conditions. This enables the operator to choose the best operational strategy at any given time, while providing estimated energy consumption indicators for every scenario.