微生物胞外多糖SM-A87EPS固定化条件优化及对Pb(Ⅱ)吸附的研究  

Parameter optimization for immobilization and Pb(Ⅱ) adsorption of microbe exopolysaccharide SM-A87 EPS

作　　者：孟凡平[1] 周维芝[1] 马玉洪[1] 高金强[1] 

机构地区：[1]山东大学环境科学与工程学院,山东济南250100

出　　处：《山东大学学报（工学版）》2011年第3期160-166,共7页Journal of Shandong University（Engineering Science）

基　　金：国家自然科学基金资助项目(50878120);山东省自然科学基金资助项目(Z20081309);山东大学校级交叉学科基金资助项目(2009JC017);山东省科技攻关资助项目(2010G0020606);济南市高校自主创新计划资助项目(201004041)

摘　　要：为了解决微生物胞外多糖(exopolysaccharide,EPS)Wangia profundaSM-A87(SM-A87 EPS)的分离问题,选用环境友好材料聚乙烯醇(polyvinylalcohol,PVA)和海藻酸钠(sodium alginate,SA),通过正交试验设计对微生物胞外多糖SM-A87 EPS固定化条件进行了优化,并对固定化SM-A87 EPS小球的吸附效能进行了初步研究。以PVA、SA、EPS的质量分数及硬化时间为因素,以Pb(II)去除率为主要指标,成球性、多糖溶出率、耐酸性为辅助指标,获得了固定化EPS小球的最优配比为m(PVA)∶m(SA)∶m(EPS)∶m(H2O)=80∶20∶1∶1 000,硬化时间为16 h。通过批次实验,研究了固定化小球用量、pH值、吸附时间对固定化EPS小球吸附Pb(Ⅱ)的影响。结果表明固定化小球对Pb(Ⅱ)的去除率随吸附剂用量的增加而升高;pH值对固定化小球吸附Pb(Ⅱ)有影响;浸泡组的吸附速率大于干燥组的吸附速率。Langmuir等温线能够较好地拟合固定化EPS小球吸附Pb(Ⅱ)的热力学过程,相关回归系数为0.954,最大理论吸附量为82.64 mg/g。准二级动力学模型能够较好地拟合固定化EPS小球吸附Pb(Ⅱ)的动力学过程,吸附过程受两个以上的阶段控制。In order to improve the separation efficiency of microbe exopolysaccharide（EPS） Wangia profunda SM-A87 EPS（SM-A87 EPS） from aqueous solution,the preparation of immobilized SM-A87 EPS was optimized by orthogonal array design experiments.The four main factors were concentration of the polyvinylalcohol（PVA）,sodium alginate（SA）,EPS,and the hardening time.The major relevant indicator was Pb（Ⅱ） removal rate,while three subordinate indicators were the spherical shape,extraction rate of the polysaccharide and acid resistance of the immobilized EPS grains.The results showed that the optimal ratio of immobilized SM-A87 EPS was obtained as m（PVA）∶ m（SA）∶ m（EPS）∶m（H2O）=80∶ 20∶ 1∶ 1 000,and the hardening time was 16 h.Effects of immobilized EPS beads dosage,pH,and adsorption time were studied by batch experiments.The results showed that the removal rate increased with the immobilized EPS beads dosage increasing.The adsorption of Pb（Ⅱ） onto the immobilized beads depended on the pH value.The adsorption rate of the immersed beads was faster than that of the dry beads.The thermodynamic isotherm of Pb（Ⅱ） adsorption on immobilized EPS beads could be best described by the Langmuir model,with a regression coefficient of 0.954 and a theoretical maximum adsorption capacity of 82.64 mg/g.The pseudo-second-order model well fitted the kinetic process of Pb（Ⅱ） adsorption by immobilized EPS beads,and the adsorption process was controlled by more than two steps.

关 键 词：固定化 胞外多糖 Pb(Ⅱ)吸附 

分 类 号：X52[环境科学与工程—环境工程]