Chemically modified chitosan polymers for bromate removal

Bromate is a harmful byproduct formed during drinking water disinfection processes. In this work, adsorption of bromate by natural chitosan and its chemically modified polymers has been investigated. Bromate adsorption was found between 22.73 mg/g and 43.48 mg/g. Adsorbents were analysed by Fourier transform infrared-ATR spectroscopy. It is suggested that chemical adsorption is the main bromate adsorption mechanism. By fitting theoretical results to experimental data, it is shown that the Langmuir adsorption model and the second-order kinetic model are more applicable to explain the adsorption process. Furthermore, increased bromate adsorption is found at high temperature and at low pH, while coexisting ions have little influence at low concentrations.