Strathkelvin Instruments/ASP-Con Case Studies
Evides Poster- Click to See the Case Study in Full.
Evides Industriewater operates a waste water treatment plant (WWTP) in Vlissingen (The Netherlands) for the biological treatment of both industrial and sanitary waste water from approximately 60 companies. The influent is a mixture of waste water from the food industry and (petro-) chemical industry. The easy degradable wastewater from the food industry is transported separately and pre-treated in an anaerobic treatment step, after which it is post-treated in an aerobic activated sludge process. The aerobic process purifies the entire influent flow. The system consists of a carousel-type aeration tank and a final settlement tank. The carousel is operated with an aerated part for biological oxygen demand (BOD) removal and nitrification and an anoxic zone where denitrification takes place. The composition and degradability of the wastewater can vary greatly, making it a challenge to control the sludge volume index (SVI) and to avoid non-conformities. The objectives are to reduce the energy demand and to reach the lowest possible discharge concentrations of nitrogen components. All of this with a fully automated WWTP whereby the operating personnel only have to intervene on high-priority failures.In order to realize this, a new measurement and control concept was developed in which the aeration in the carousel is controlled via a multiple parameter monitor including on-line respiration and ammonium analysis. It will be demonstrated that this control system will save 20% – 25% on energy immediately, and, in time, saves 20% on discharge billing.