Lauroyl arginate ethyl: An effective antibiofouling agent applicable for reverse osmosis processes producing potable water

•LAE was evaluated for application as a biocide for biofouling control in RO processes.•RO membrane was resistant to morphological and physicochemical damage by LAE.•LAE showed higher antimicrobial and antibiofilm effects than DBNPA.•LAE can be directly dosed in RO vessels for potable water production.

Biofouling is a major operational problem in reverse osmosis (RO) processes. Although direct dosing of non-oxidizing biocides (e.g. DBNPA) in RO vessels is an effective method for reducing biofouling, the application of non-oxidizing biocides to the production of potable water is strictly banned due to their human toxicity. In this regard, while food preservatives (i.e. non-toxic to human ingestion) can be used for this purpose, a systematic evaluation has not been conducted. Here, we explored the applicability of a food preservative, lauroyl arginate ethyl (LAE), to RO processes for potable water production. The compatibility of LAE with the RO membrane was tested by exposing the membrane to high concentrations of LAE. The membrane showed no significant morphological or chemical damage up to 100,000 mg/L. LAE demonstrated high and fast antimicrobial activities, which was verified by measuring the minimum concentrations needed to inactivate and kill bacteria, measuring the inhibition zones, and analyzing the rates of bacterial killing. LAE was also effective in inhibiting biofilm formation and removing biofilm formed on the RO membrane. Furthermore, LAE did not negatively affect the RO performance factors such as water flux and salt rejection. Taken together, this study clearly demonstrated that LAE can be used to reduce biofouling in RO processes without risk of human toxicity.

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