On The Relationship between Suspended Solids of Different Size, the Observed Boundary Flux and Rejection Values for Membranes Treating a Civil Wastewater Stream

Membranes

Marco Stoller¹  Javier Miguel Ochando Pulido² 

[1] Department of Chemical Materials Environmental Engineering, University of Rome “La Sapienza”, Via Eudossiana 18, Rome 00184, Italy; E-Mail:;Chemical Engineering Department, University of Granada, Granada 18071, Spain; E-Mail:

关键词: membrane fouling;    membrane selectivity;    boundary flux;    wastewater treatment;   

DOI  :  10.3390/membranes4030414

来源: mdpi

【 摘 要 】

Membrane fouling is one of the main issues in membrane processes, leading to a progressive decrease of permeability. High fouling rates strongly reduce the productivity of the membrane plant, and negatively affect the surviving rate of the membrane modules, especially when real wastewater is treated. On the other hand, since selectivity must meet certain target requirements, fouling may lead to unexpected selectivity improvements due to the formation of an additional superficial layer formed of foulants and that act like a selective secondary membrane layer. In this case, a certain amount of fouling may be profitable to the point where selectivity targets were reached and productivity is not significantly affected. In this work, the secondary clarifier of a step sludge recirculation bioreactor treating municipal wastewater was replaced by a membrane unit, aiming at recovering return sludge and producing purified water. Fouling issues of such a system were checked by boundary flux measurements. A simple model for the description of the observed productivity and selectivity values as a function of membrane fouling is proposed.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.