Effect of Two Psychrotrophic Calcium Carbonate Mineralized Bacteria on the Surface Repair of Marble
LI Qiong-fang;HE Xin;CHEN Chao;YANG Qing-qing;LYU Zhi-zhou;School of Life Science and Engineering,Southwest University of Science and Technology;School of Civil Engineering and Architecture,Southwest University of Science and Technology;
The mineralization induced by bacteria is an effective method for the restoration of stone relics.To explore the repair effect of biomineralization in low temperature region,2 psychrotrophic strains with high activity of carbonic anhydrase( CA) were isolated from cold water of Huanglong travertine deposition area. Calcium carbonat mineralization was induced by the 2 strains on the marble surface. The solution p H value, surface mineral deposition, surface morphology, surface water absorption, surface air permeability and surface acid resistance of marble during and after the mineralization process were analyzed by means of p H measure,SEM,XRD and other testing methods. The results were listed as following. Under the treatment with living bacteria or dead bacteria,the marble surface was covered with a dense calcified layer of calcite and the morphology was regulated by the bacteria. The living bacterial cells generated more homogenous and dense mineralized layer than dead cells. The remediation effect of long-term was more obvious than that of short-term. Compared with the blank specimen,the specimen with a mineralization layer show higher ability of corrosion prevention on water imbibitions, gas permeability and acid stability. The results would provide a theoretical basis for the restoration of stone relics under low temperature.