不同材料固定香菇废弃菌柄对铅和镉的吸附

研究了用聚乙烯醇-海藻酸钠(PVA-SA),海藻酸钠(SA)和琼脂三种材料固定香菇(Lentinus edodes)废弃菌柄制作成吸附小球的理化特性,初步比较了三种小球和自由菌粉的吸附能力,在此基础上进一步分析了PVA-SA香菇小球吸附Pb2+和Cd2+的动力学。结果表明,PVA-SA香菇小球的成球性,机械强度和耐酸性最好。固定小球的吸附能力比自由菌粉的有所下降,以Cd的吸附率降低幅度较大,PVA-SA香菇小球和SA香菇小球对Pb的吸附率降低幅度较小,吸附率分别为92.4%和92.7%,对Cd的吸附率分别为55.9%和58.66%。伪二级动力学模型能够很好的拟合固定小球对Pb2+和Cd2+吸附的动力学过程,相关系数R2分别为0.9999和0.9904,由伪二级动力学方程得到的Pb2+和Cd2+理论平衡吸附量qe分别为0.4926和0.1448mg/g,跟实验测定获得的数据0.4635mg/g和0.1423mg/g相近。

Comparison among Immobilized Lentinus deodes Residue of Different Materials on Pb2+ and Cd2+ Biosorption

Immobilized L. edeodes residue by polyvinyl alcohol-Na-alginate(PVA-SA),Na-alginate and agar respectivelywere prepared,with pilot study done in relation to absorbing ability of lead and cadmium from aqueous solution by the threedifferent immobilized cells. The mechanical density,acid resistance and sphericity were also studied. Results showed thatconsidering mechanical density,acid resistance and sphericity,the best immobilized cell were PVA-SA beads,whose Pb2+and Cd2+ biosorption process can be well fitted by pseudo second-order model,with coefficient value 0.9999 and 0.9904respectively,and close to the experimental data of 0.4635mg/g and 0.1423mg/g.