ScienceAsia 43(2017): 1-7 |doi:
Microbially induced CaCO3 precipitation: hydraulic response and micro-scale mechanism in porous media
Yefei Tana,*, Xinghua Xiea, Shiqiang Wua, Tao Wub
ABSTRACT: Microbially induced CaCO3 precipitation (MICP) is a natural process which has recently been applied as a technique for soil solidification and hydraulic conductivity reduction. In the present study, laboratory-based MICP tests were carried out in four columns containing sand with different particle sizes together with cultures of Sporosarcina pasteurii. A calcium solution was supplied continuously to the columns at a speed of 0.97 ml/min to mimic underground seepage. Hydraulic conductivities in the columns were monitored by hydraulic tests before and during MICP. Results showed that the reduction in conductivity values could be as high as 97% after 24 h of MICP. Columns clogged with calcite precipitates were examined by environmental scanning electron microscopy and energy dispersive X-ray spectroscopy. Calcite precipitation was shown to be the reason for hydraulic conductivity reduction. The calcium precipitation rates and amounts were quantified and verified.
||Nanjing Hydraulic Research Institute, Nanjing, 210029, China
||Jiangsu Provincial Centre for Disease Control and Prevention, Nanjing, 210024, China
* Corresponding author, E-mail: email@example.com
Received 27 May 2017, Accepted 0 0000