Study of copper-charged membranes for control of fouling due to bacteria and algae organic matter

Abstract

The accumulation of micro-organisms, along with the presence of nutrients, forms biofilms. Biofoulants that are typically encountered in desalination systems include cellular organisms (e.g. bacteria or algae) and organic debris, including algae organic matter. The accumulation of these micro-organisms is problematic to membranes by causing irreversible fouling. The most adverse effects due to biofouling include declines in permeate flux and salt rejection. In addition, biofilm formation necessitates frequent membrane cleaning, increasing operating costs and decreasing membrane life. The goal of this research was to investigate the performance of low-fouling copper-charged membranes for microbial resistance. The extent of fouling on the microbial resistant membranes was characterized by assessing surface area coverage by image analysis. Fluorescent microscopy was used to determine activity of biofilm cells on the surface. The presence of extracellular polymeric substance was verified using Fourier transform infrared spectroscopy. The permeate flux values were compared for both unmodified and copper-charged membranes by conducting dead-end filtration experiments using synthetic brackish water.