Long-term evaluation of different strategies of cationic polyelectrolyte dosage to control fouling in a membrane bioreactor treating refinery effluent

ABSTRACT

In this article, the long-term use of cationic polyelectrolyte to improve the sludge filterability and to control membrane fouling in bioreactor membrane while treating refinery effluents have been evaluated in pilot scale. Corrective and preventive cationic polyelectrolyte dosages have been added to the membrane bioreactor (MBR) to evaluate the membrane fouling mitigation in both strategies. The results have confirmed that the use of the Membrane performance enhancer (MPE) increased the sludge filterability and reduced the membrane fouling. During the monitoring period, stress events occurred due to the increase in oil and grease and phenol concentrations in the MBR feeds. The preventive use of cationic polyelectrolyte allowed for a more effective and stable sludge filterability, with lower cationic polyelectrolyte consumption and without decreasing MBR's overall pollutant removal performance.

KEYWORDS:

• Membrane bioreactor
• fouling
• refinery effluent
• membrane performance enhancer
• sludge filterability

Acknowledgements

The authors acknowledge the Department of Sanitary and Environmental Engineering of the Federal University of Minas Gerais (DESA/UFMG), Petrobrás, the National Council for Scientific and Technological Development (CNPq), the Coordination for the Improvement of Higher Level Personnel (CAPES) and the Foundation for Research Support of the State of Minas Gerais (FAPEMIG) for their permanent support.

Disclosure statement

No potential conflict of interest was reported by the authors.