Flux influence on membrane fouling in a membrane bioreactor system under real conditions with urban wastewater

Abstract

In order to evaluate the effect of flux on membrane fouling, the performance of a bench-scale submerged membrane bioreactor (MBR) equipped with ultrafiltration membranes (ZENON®) was investigated under real conditions at different flux rates. The pilot plant was located at the wastewater treatment plant of the city of Granada (Spain). Influent used in the experiments came from the primary settling tank. Assays carried out under different operating conditions indicated that dTMP/dt increased in accordance with the increase in flux. The results showed a significant impact on the rate of transmembrane pressure, while the behavior of membrane fouling was logarithmic with respect to the flux. These findings could be of some importance for understanding the behavior of the membrane, since over 20.57 L m⁻² h⁻¹ the flux rate produced a significant increase in transmembrane pressure. The data therefore suggest that an increase in the net flux significantly affects membrane fouling.

Keywords:

• Membrane bioreactor
• reuses
• wastewater treatment
• ultrafiltration
• MLSS
• fouling

Acknowledgment

This study was supported by a grant from the Ministry of Science and Technology, Spain (reference REN2002-04293-C02). Both J.M. Poyatos and M. Molina-Muñoz received PhD scholarships from the Ministry of Education and Science (PFPI, MEC, Spain).