Efficacy testing of non-oxidizing biocides for polyamide membrane biofouling prevention using a modified CDC biofilm reactor




Da-Silva-Correa, Luiz H.
Aasen, Kristen
Gamm, Nicole E.
Godoy, Rafaela
Rahmati, Negar
Buckley, Heather Louisa

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AQUA - Water, Infrastructure, Ecosystems and Society


Biofouling is one of the most challenging obstacles faced by reverse osmosis (RO) membrane systems to supply potable water. Currently, biofouling is imperfectly handled by RO feed water pre-chlorination, which is associated with the production of carcinogenic disinfection by-products. To propose a safer alternative to control biofouling in RO drinking water applications, this study investigates the efficacy of five biocides to prevent and remove Pseudomonas aeruginosa biofilms from RO membranes: 2-methyl-4-isothiazolin-3-one (MIT); 2,2-dibromo-3-nitrilopropionamide (DBNPA); sodium bisulfite (SBS); sodium benzoate (SB); and ethyl lauroyl arginate (LAE). Experiments were conducted on the Center for Disease Control (CDC) Biofilm Reactor (CBR) with biocidal dosing estimated on 96-well microtiter plates. Confocal Scanning Laser Microscopy (CLSM) and Scanning Electron Microscopy (SEM) were used to analyze the biocides' anti-biofilm efficacies under dynamic conditions relative to minimum biofilm inhibitory and eradication concentrations. The results in this study indicated that LAE presented the best anti-biofilm efficacies in treating P. aeruginosa biofilms when compared to all studied biocides; it not only prevented biofilm formation (>98%) but also it effectively removed pre-established biofilms (>99%) from RO membrane coupons. Therefore, due to safety and efficacy, LAE is an excellent candidate for controlling biofouling in drinking water RO membrane systems.


This work was done at the Civil Engineering Department, Green Safe Water Lab, University of Victoria, Victoria, British Columbia, Canada. The authors acknowledge the provision and support of the SEM, CLSM, BioCore, and CAMTEC research facilities at the University of Victoria.


biocides, biofilm prevention, biofouling, drinking water, polyamide membranes, reverse osmosis


Da-Silva-Correa, L. H., Aasen, K., Gamm, N. E., Godoy, R., Rahmati, N., & Buckley, H. L. (2023). Efficacy testing of non-oxidizing biocides for polyamide membrane biofouling prevention using a modified CDC biofilm reactor. AQUA - Water, Infrastructure, Ecosystems and Society, 72(3), 313-328. https://doi.org/10.2166/aqua.2023.217