Plackett-Burman Design与均匀设计法优化玫瑰色微球菌固定化脱氮的性能

Application of Plackett-Burma Design and Uniform Design to the optimization of nitrogen removal performance of immobilizing Micrococcus roseus

摘要:

【目的】采用Plackett-Burman Design (PBD)与均匀设计(Uniform Design, UD) 优化玫瑰色微球菌(Micrococcus roseus)固定化脱氮的条件，以提高其脱氮性能。【方法】选择聚乙烯醇(Polyvinyl alcohol，PVA)与海藻酸钠(Sodium alginate，SA)作为固定化细胞材料，研究其成球方式与性能，应用PBD对9个影响脱氮效果的因素进行显著性检验，筛选出PVA、SA、温度、菌液接种量、菌球量5个显著性因素(P<0.05)。采用UD对5个显著因素进行条件优化，优化数据通过Minitab与Matlab软件进行逐步回归分析，并建立二阶多项式模型。【结果】最优脱氮条件为PVA 9.6%、SA 2.2%、温度33.4 °C、菌液接种量8%、菌球量500个/100 mL，连续脱氮72 h，最高脱氮率达到60.9%。【结论】PBD与UD的联合使用能够在显著因子筛选与寻优中发挥重要的作用。连续脱氮试验表明，玫瑰色微球菌去除氨氮主要通过同化、硝化与反硝化途径。

Abstract:

[Objective] A combination of Plackett-Burman Design (PBD) with Uniform Design (UD) was applied to optimize the nitrogen removal performance of immobilizing Micrococcus roseus. [Methods] Polyvinyl alcohol and Sodium alginate were used to immobilize cells. Using PBD, five factors including PVA, SA, temperature, the inoculation amount and the amount of pellet were selected from nine factors based on their significance (P<0.05). Next, UD was used to further optimize these five significant factors in order to improve nitrogen removal effect. Further, these data were analyzed by stepwise regression and second-order polynomial, which were based on Minitab and Matlab. [Results] The optimum conditions are as follows: PVA 9.6%, SA 2.2%, 33.4 °C, the inoculation amount 8%, the pellet number 500 per 100 mL, and the highest value of nitrogen removal rate peaked 60.9% after 72 h operation for nitrogen removal. [Conclusion] The combination of PBD with UD is an effective way to select significant factors for the optimization of denitrification performance of Micrococcus roseus. And Micrococcus roseus removes ammonia mainly through assimilation, nitrification and denitrification.