珊瑚砂微生物固化条件优化的正交试验研究

Orthogonal Experiments on Optimization of Biocementation Conditions for Coral Sand

珊瑚砂微生物固化影响因素众多,选取颗粒粒径、脲酶活性、底物溶液浓度和配比四个主要影响因素,每个因素取三个水平,对珊瑚砂进行了微生物固化正交试验,研究了各因素对珊瑚砂微生物固化体无侧限抗压强度及干密度增量的影响,得出了最优固化条件。试验结果表明,各因素对固化体无侧限抗压强度影响的主次顺序为:颗粒粒径、脲酶活性、底物溶液配比、底物溶液浓度;对固化体干密度增量影响的主次顺序为:脲酶活性、颗粒粒径、底物溶液配比、底物溶液浓度;综合无侧限抗压强度和干密度增量结果得到珊瑚砂微生物固化的最优条件为:颗粒粒径取粗粒组,脲酶活性取1.85 mmol/(L·min),底物溶液配比取0.75∶1,底物溶液浓度取1 mol/L。

There are many influencing factors in biocementation of coral sand, of which four main influencing factors particle size, urease activity, substrate solution ratio and substrate solution concentration were selected, each factor took three levels, and the coral sand was subjected to microbial solidification orthogonal test. The effects of various factors on unconfined compressive strength and dry density increment of biocemented coral sand columns were analyzed. And the optimum biocementation conditions were ob-tained. The results showed that, the primary and secondary order of factors on unconfined compressive strength of columns is: particle size, urease activity, substrate solution ratio, substrate solution concentration. The primary and secondary order of factors on dry density increment of columns is: urease activity, particle size, substrate solution ratio, substrate solution concentration. Optimal condition for the biocementation of coral sand by the results of unconfined compressive strength and dry density increment is coarse particle group, and the urease activity is 1.85 mmol/(L min), the ratio of substrate solution is 0.75:1, and the substrate solution concentration is 1 mol/L.