Kinetic biomineralization through microfluidic chip tests.

A homogeneous microfluidic chip was used to investigate the pore-scale characteristics during the process of microbially induced calcium carbonate precipitation (MICP). An image-processing scheme was developed to measure the projecting areas of the precipitated calcium carbonate. Calcium carbonate first precipitated on the bacterium side before spreading to the rest of the chip. The distribution of calcium carbonate was more uniform along the length of the microchip than along the width. Raman back-scattering spectroscopy was used to examine the chemical composition of the precipitate, identifying calcite and vaterite as the main mineral phases. Bacterium traces were noted on crystal surfaces in SEM images, suggesting a higher adsorptive capacity for irregular precipitates than well-shaped crystals. [ABSTRACT FROM AUTHOR]