[Optimization immobilizing activated carbon and bacteria by sodium alginate and its character of adsorption of Pb2+]

Through the immobilized biosorption of activated carbon and Paenibacillus polymyxa GA1 by sodium alginate, this paper take advantage of the orthogonal experiment to investigate the adsorption characteristics of sodium alginate. According to the research, the optimal preparation conditions were as following: the mass fraction of sodium alginate was 2.5%; the amount of carbon and bacteria was 1:20 and 1:2, respectively; under the preparation condition, the adsorption rate could reach to 93.74%. The adsorption conditions of the immobilized beads were: pH 5, temperature 30 degrees C and Pb2+ with an initial concentration of 300 mg x L(-1). Moreover, the immobilized activated carbon and GA1 improved their application range of pH, temperature and the initial concentration of Pb2+. Based on the equilibrium curve, it showed that the adsorption of Pb2+ was a rapid process within 30 min and gradually reached leveling within 2 h. What's more, the equilibrium curve could be well described by Langmuir model and Freundlich model, which be consisted mainly of monolayer adsorption, and the maximum monolayer adsorption amount was 370.37 mg x g(-1). Finally, the desorption result showed that the immobilized beads could be recycled effectively.