Optimization of nutrient removal with on-line monitoring and dynamic simulation

Many Wastewater Treatment Plants (WWTP) have to reach stricter effluent standards. WWTPs loaded with a low F/M-ratio can often reach these standards by process optimization, without extension of the plant. This paper presents the step by step approach of the process optimization. An important step is a three week period of on-line monitoring of ammonium, nitrate and phosphorus: the analyses provide information about changes of effluent quality within the day. Another important step is process modelling. The model is calibrated by the on-line measurements. Process modelling enables a comparison of the effectiveness of different process modifications. This approach is applied at a WWTP of the Friesland Waterboard.