Characteristics and mechanisms of Cu(II) sorption from aqueous solution by using bioflocculant MBFR10543

This paper investigated the characteristics of Cu(II) sorption from aqueous solution by using bioflocculant MBFR10543 and discussed the mechanism during the sorption process. Results have demonstrated that the removal efficiency of Cu(II) reached 96.9 % by adding MBFR10543 in two stages, separately, 1.5 x 10(-2) % (w/w) in the 1.0-min rapid mixing (180 rpm) and 2.0 x 10(-2) % (w/w) after 2.0-min slow mixing (80 rpm), with pH value fixed at 6.0. Cu(II) sorption process could be described by the pseudo-second-order kinetic model and the Langmuir isotherms model. The negative Gibbs free energy change indicated the spontaneous nature of the sorption. Fourier transform infrared spectra analysis indicated that functional groups, such as -OH, -COOH, Ca center dot O, and -NH2, were existed in MBFR10543 molecular chains, which had strong capacity for removing Cu(II). Furthermore, both charge neutralization and bridging being the main mechanisms involved in Cu(II) removal by MBFR10543.