The harmful effects generated by biofilms have an extremely high cost. In this study, we were interested in the formation of marine biofilm occurring on the wellknown anionic dialysis membrane AN69 for its application to the reduction of seawater salinity for the preparation of body-washing solutions. We focused our study on two membranes, AN69 and AN69 modified (denoted AN69mod) by sorption of a cationic polyelectrolyte the poly(diallyldiméthylammonium), denoted PDADMA. Physico-chemical characteristics (membrane charge from transport numbers of Li+ and streaming potential measurements, water flux from hydraulic permeability measurements and morphological/topographical measurements using SEM and AFM, respectively) of both membranes were followed during exposition to E. coli and natural marine biofouling solutions. Our results showed for the first time that the modification by the PDADMA reversed the charge of the AN69 membrane and increase its affinity for bacteria creating from electrostatic affinity. Then it appeared clearly that electrostatics forces are the main forces responsible of biofouling apparition. Furthermore we have elaborated a very simple antibiofilm protocol based on a one step dipping operation applied to the fouled AN69 membrane in order to regenerate the AN69 eliminating the PDADMA with the bacteria. Then we were able for the first time to eliminate easily all marine bacteria deposited in order to reuse the AN69 membrane, for a sustainable development of this dialysis membrane.
dialysis membrane AN69; antifouling coating; poly(diallyldimethylammonium) ; Escherichea Coli; marine biofouling.
Maxime Pontié, Université d’Angers, Groupe Analyses et Procédés (GAP), UFR Sciences, 2 Bd. Lavoisier, 49045 Angers cedex 01, France