Replacement Of Synthetic Polymer By Bio-Based Flocculant In Drinking Water Treatment Train: Impact On Water Quality And Microbiological Colonization

The use of anionic potato starch in clarification was assessed by comparison with polyacrylamide flocculant in order to evaluate its effect on the performances of Actiflo® Turbo combined with Sand Filtration and Actiflo® Turbo combined with Ultrafiltration in terms of water quality and kinetics of biofilm formation. For similar treated water quality, results indicate similar performances regarding removal of biodegradable organic carbon which contributes to bacterial regrowth in the water distribution networks. In addition, chlorine consumption is not higher for waters treated using starch based flocculant and the concentration of disinfection by-products is much lower than the regulatory threshold in water supply. The microbiological data on water and biofilm in the effluents generated in different steps of the treatment processes show that the use of natural starch-based polymers, when dosed at concentration of 1 to 2 mg/l, do not cause any favorable conditions for the bacterial growth in water distribution networks.