Statistical Modeling of Environmental Factors on Microbial Urea Hydrolysis Process for Biocement Production

Table 1

Experimental range of amount and levels of the factors.

Factors	Unit	Symbol	Range of amount and concentration
Initial cell concentration	Cell/mL		10^6	10^7	10^8
Urea concentration	M		0.1	0.55	1
Temperature	°C		20	35	50
Level coded			−1	0	+1