Effects of temperature and salinity on concrete-surface treatment by bacteria in marine environment

Abstract

The present study investigated the effects of temperature and salinity on CaCO3 production metabolism by soil bacteria. S. pasteurii was incubated in a urea-calcium lactate medium with the variables of salinity (0.5, 2, and 3.5%) at 10, 20, and 30 degrees C. The effects of temperature and salinity on the growth, activity of urea hydrolysis, and CaCO3 production were determined by comparing the growth rate and the changes in concentration of the NH4+ and Ca2+. The effects of temperature and salinity on concrete surface treatment by S. pasteurii were conducted by water absorption test. The CaCO3 precipitation metabolism of S. pasteurii was predominantly affected by temperature, while there was no significant difference in the metabolic capacity in terms of salinity. The water absorption rate of surface-treated concrete reduced with increasing temperature and salinity.