ENREM - Enhanced Nutrients Removal in Membrane Bioreactor

The project implemented a wastewater treatment process based on membrane bioreactor technology for biological advanced nutrients removal. The process is an economical solution for remote and small wastewater schemes where high treatment performances are required for bathing areas and areas of sensitivity (disinfection and low nutrients concentration in the treated water). . The biological process and design/operation criteria applied reached the expected treatment targets of up to 99% phosphorus elimination and 90% nitrogen elimination. The ENREM project showed also that a combination of a separated collection sewer together with a puffer reactor enables the optimisation of the size of the reactor volume and membrane surface. The use of a low-pressure sewer is seen as an additional advantage: first it ensures that the wastewater is devoid of storm water; second, it may enhance the presence of volatile fatty acids required for the biological nutrients removal through the one to two-day residence time in the shafts and sewer. While the project demonstrated the process’ technically viability, a cost analysis highlighted that the operation costs are high and can be justified only in case of advanced treatment requirements.