Development of Quaternized Biopolymeric Flocculants for Water Treatment

Abstract

Providing safe drinking water is an important public health issue and recent studies have recognized commonly used flocculants and disinfectants responsible for unintended health hazards. An increased resistance of waterborne pathogens to synthetic biocides and environmental considerations underpin an urgency to develop strong, economically viable and ecofriendly replacements of conventional synthetic flocculants and disinfectants. Distinctive nature of microbial extracellular polymers containing amino groups can be explored in hope to obtain effective and safe substitute to chemical biocides. Although, many natural and synthetic water treatment agents are available in the market, but natural products are not as efficient as the semi-synthetic or synthetic compounds in terms of efficacy. Thus in the present study, an attempt was made to design a semi-synthetic flocculant-disinfectant replete with sustainability, cost effectiveness, biocompatibility, non-toxic polymers with high inactivation efficacy of waterborne pathogens. In an attempt to develop antibacterial polymer(s) with dual flocculant-disinfectant property, we chemically altered the surface properties of an amino sugar rich biopolymeric flocculant produced by Klebsiella terrigena. Chitosan, most extensively modified polymer, was used as reference compound due to its structural similarity to the bioflocculant. Alteration were brought about in the native biopolymers through quaternization, and the trimethyl biopolymeric derivatives (N,N,N trimethyl biopolymer and N,N,N trimethyl chitosan, abbreviated as TMB and TMC, respectively) were analyzed physically, chemically and for flocculating properties. TMB did not differ significantly (plt0.05) in either chemical, physical properties or flocculating ability when compared to its native counterpart.