海藻酸钠包埋活性炭与细菌的条件优化及其对Pb2+的吸附特征研究

利用海藻酸钠固定化包埋活性炭与多黏类芽孢杆菌GA1,通过正交试验研究海藻酸钠溶液浓度、包炭量及包菌量吸附Pb2+的最佳配比,并研究了这种新型的固定化小球对Pb2+的吸附特征.结果表明,固定化活性炭与多黏类芽孢杆菌GA1小球最佳制备条件为海藻酸钠质量分数2.5%、包炭量1:20和包菌量1:2,在该制备条件下吸附率达到93.74%.固定化小球的最佳吸附条件为pH5、温度30℃和Pb2+初始浓度300mg·L-1,活性炭与GA1经固定后对pH、温度和Pb2+初始浓度适应范围扩大.吸附平衡曲线表明,对Pb2+的吸附在30min内是一个快速的过程,在2h时基本趋于平衡,且平衡曲线能较好地用Langmuir模型和Freundlich模型来描述,其吸附过程主要为单分子层吸附,最大单分子层吸附量为370.37mg·g-1.解吸结果表明固定化小球能有效地循环利用.

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.