A Research On The Immobilizing Activated Carbon And Bacteria By Sodium Alginate And Its Adsorption Of Heavy Metal

Heavy metal pollution has become to one of the serious environmental problemstoday, microbial adsorption method has many characteristics, such as widely-source,low-cost, fast-adsorption, large-adsorption, higher-selective, there is a large number oforganisms such as bacteria, fungi, yeast and algae in the environment which havestrong adsorption on metal ions. Immobilized microorganism as a new biologicaladsorbent has an advantage of high mechanical strength, solid-liquid easy separating,adsorbent easy regeneration, to be reused, and can produce to be various types ofreactors, and to achieve continuous operation.Through the immobilized biosorption of activated carbon and Paenibacilluspolymyxa GA1by sodium alginate, this paper taked advantage of the orthogonalexperiment 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 was2.5%; the amount of carbon and bacteria was1:20and1:2, respectively; under the preparation condition, the adsorption rate couldreach to93.74%.The adsorption conditions of the immobilized beads were: pH5, temperature30℃and Pb²⁺with an initial concentration of300mg L-1. Moreover, the immobilizedactivated carbon and GA1improved their application range of pH, temperature and theinitial concentration of Pb²⁺.Based on the equilibrium curve, it showed that the adsorption of Pb²⁺was a rapidprocess within30minutes and gradually reached leveling within2hours. What’s more,the equilibrium curve could be well described by Langmuir model and Freundichmodel, which be consisted mainly of monolayer adsorption, and the maximummonolayer adsorption amount was370.37mg g-1. Finally, the desorption result showedthat the immobilized beads could be recycled effectively.There are usually many kinds of heavy metal ions in the Wastewater, the results ofthe adsorption of Pb²⁺、Zn²⁺and Cd²⁺by immobilized balls showed that the existenceof other ions could affect another kind of metal ions’ adsorption.