Microbial Induced Calcium Carbonate Precipitation (MICP) Using Pig Urine as an Alternative to Industrial Urea

Abstract

Biocalcification by microbial induced CaCO3 precipitation (MICP) (catalyzes by microbial enzyme urease) is a promising field of research in recent decades due to its versatile application in industry. Besides, the animal waste disposal has attracted much attention owing to increasing awareness of environmental protection and resource substitution. Though, the biotechnical application of Pig urine which causes of environmental pollution due to existence of high amount of urea or pig urea (PU), not study yet. Present study, PU was used instead of industrial urea, first time, as the enzymatic substance to produced CaCO3 by four sets of experimental quartz-sand column (Control, A (4 h), B (6 h) and C (12 h)) with different injection time intervals (4 h, 6 h and 12 h), bacterial (Sporosarcina pasteurii, DSM 33) amount, pig urine and with 1.1 (M) CaCl2. The results revealed the precipitation of CaCO3 from PU and CaCl2 in presence of S. pasteurii. The porosity and permeability of the quartz-sand column was noted to decrease with the application of pig urine. The mechanical properties (anti-permeability) of the quartz-sand columns were noticed better, while time interval between (4 h) the application of pig urine and bacterial solution was shorter (CaCO3 formation increase by 43%, compare to control). The XRD and SEM results displayed the CaCO3 formation, which confirmed the feasibility of PU as carbonate source. The findings implied a cost reduction of MICP technology by using pig urine as urea, animal waste mitigation for environmental pollution and resource substitution.