Green Inhibitor as Antibacteria and Antiscaling in Reverse Osmosis Desalination Plants

Abstract

Today, reverse osmosis membranes are the leading technology for new desalination installations, however, a challenge facing widespread application of RO technology is membrane fouling. In the present study, we used an environmentally friendly green inhibitor as anti-scaling and anti-biofouling in reverse osmosis (RO) desalination plants. The influence of Sargassum sp., Corallina mediterranea, and Avicennia marina on RO membrane mineral scaling was evaluated using gypsum as a model scalant. Antibacterial properties for three marine extracts from Sargassum sp., C. mediterranea, and Avicennia marina were investigated with Gram-positive bacteria (ArthrobactersulfureusYACS14, Staphylococcus aureus) and Gram-negative bacteria (VibrioanguillarumMVM425, Escherichia coli). The antimicrobial results were detected for the two selected extracts as the most potent extracts (ethyl acetate, methanol crude extracts of the Avicennia marina leaves). Data showed that ratios of 3 and 5% recorded the highest suppression percentages (100%) for all tested bacteria including bacterial community collected from Eastern Harbor. On the other side, data confirmed that the anti-scalant properties by 100 ppm of Avicennia marina leave extract giving 85% of scale inhibition. The effect of Avicennia marina leaves extract for calcium sulfate dihydrate (gypsum) scaling on selected reverse osmosis (RO) membrane surfaces was investigated. The effect of different concentrations of Avicennia marina leaves extract was observed in the extent of surface scale coverage and surface crystal size among the membrane studied.