review on microbial induced calcite precipitation
Sangeetha.H,P.K.Swetha
Published in International Journal of Advanced Research in Civil,Structural,Environmental and Infrastructure Engineering and Developing
ISSN: 2320-723X Impact Factor:1.7 Volume:3 Issue:1 Year: 07 March,2017 Pages:364-367
Abstract
Soil improvement by using microbial induced carbonate precipitation is new and innovative technique for granular soils. It utilizes bacteria to hydrolyse urea to give to give carbonate ions which react with a calcium rich solution to produce calcium carbonate bacteria are injected to soil. It increases strength and stiffness which is measured by unconfined compression tests and permeability changes from falling head method. MICP reduces permeability and liquefaction. An important factor in achieving uniform precipitation is proper injection of reagents of ureolytic bacteria, urea, calcium, staged injection including retention periods and with a pressure head applied during injection of the bacterial cell solution, proved most effective.Greater improvements in stiffness and strength were achieved for lower bacterial cell and higher cementation solution concentrations with a higher molarity of urea (non-equimolar solutions) proving even more effective. This review discusses on findings which are confirmed by scanning electron microscope observations.
Kewords
MICP, urea hydrolysis, scanning electron microscope, CaCO3
Reference
#1. Soon NW, Lee LM, Khun TC and Ling HS (2013), Improvements in engineering properties of soils through microbial-induced calcite precipitation, KSCE Journal of Civil Engineering vol 17(4):718-728. #2. T. Komala(2013), calcite-forming bacteria located in limestone area of malayasia, journal of asian scientific research vol 3(5):471-484. #3. Wei-Soon Ng, Min-Lee and Siew-Ling Hii(2012), An overview of the factors affecting microbial-induced calcite precipitation and its potential application in soil improvement, World Academy of Science, Engineering and Technology vol 6; 02-22. #4. Achal V.Mukherjee A and Reddy MS(2010) Microbial concrete way to enhance the durability of building structures. Journal of Materials in Civil Engineering 23(6): 730-734. #5. DeJong JT, Mortensen BM, Martinez BC and Nelson DC (2010) Bio-mediated soil improvement. Ecological Engineering 36(2): 197-210.
