固定化菌藻微球的制备、表征及其对富营养化湖水的修复

以聚乙烯醇(PVA)和海藻酸钠(SA)为主要包埋材料,以活性炭、SiO2和CaCO3作添加剂,采用普通小球藻(Chlorella vulgaris)和活性污泥制备固定化菌藻微球。采用正交实验对微球的制备条件进行了优化,并对最优化条件下制得的微球进行了表征,还考察了固定化菌藻微球对某富营养化湖水的修复效果。结果表明,固定化菌藻微球的最优化制备条件为:PVA用量10%(m/v),微生物包埋量15 mL,海藻酸钠用量0.6%(m/v),氯化钙浓度2.0%(m/v)。制得的微球具有较大的比表面积,内部呈网状结构,孔径分布均匀,中孔居多,适合小球藻和微生物生长。采用固定化菌藻微球可有效修复上述湖泊的实际富营养化湖水,微球可重复使用3~4个循环,在前4个循环中,每个循环历时96 h,TN平均去除率达80%以上;TP平均去除率达90%以上;COD平均去除率达85%以上,表明固定化菌藻微球在富营养化湖水的修复方面具有潜在的应用价值。

Preparation, characterization of immobilized bacteria-algae microspheres and bioremediation of eutrophic lake water

Polyvinyl alcohol (PVA) and sodium alginate (SA) were used as major embedding materials, activated carbon, SiO₂ and CaCO₃ were used as additives, to prepare immobilized algal-bacterial beads by Chlorella vulgaris and activated sludge. The preparation conditions of beads were optimized by using orthogonal test, and the beads prepared under optimized conditions were characterized, the remediation efficiency of an eutrophic lake water by immobilized algal-bacterial beads was also investigated. The results demonstrated that the optimum conditions for preparation of immobilized algal-bacterial beads are PVA amount of 10% (m/v), microorganism embedding capacity of 15 mL, sodium alginate of 0.6% (m/v), and calcium chloride concentration of 2% (m/v). The prepared beads showed larger specific surface area, internal reticular structure, and uniform pore size distribution. Mesopore accounted for the majority of pores, which was suitable for the growth of Chlorella and microorganisms. The immobilized algal-bacterial beads were able to remedy the lake water effectively. The beads can be used repeatedly 3~4 cycles, in the first 4 cycles, each cycle lasted for 96 h, the average TN removal rate was above 80%; the average TP removal rate was above 90%; the average COD removal rate reached more than 85%, showing that the immobilized bacteria-algae beads have potential application value in the remediation of eutrophic lake water.