Exploring potential of microbially induced calcite precipitation method for sustainable stabilization of legacy landfill waste
Authors :- Patil M.; Dalal P.H.; Iyer K.K.R.
Publication :- Next Materials (Elsevier), Volume 8, 2025
Landfill mined soil like fraction (LMSF) is available in large quantities from mining of legacy landfills. Recent studies indicated the need for stabilization of LMSF for increasing its reutilization potential. In recent years, microbially induced calcite precipitation, MICP (viz., biostabilization) has emerged as an environmentally friendly biobased pathway for stabilization of soil/geomaterial. However, MICP based stabilization of LMSF has not gained the attention of researchers. In this context, the present study explores the performance of MICP stabilized LMSF using Sporosarcina Soli, a non-pathogenic species yet not explored for calcite precipitation. Compacted specimens of unstabilized/MICP stabilized LMSF were studied for their unconfined compression strength, stress-strain response, water stability and microstructural aspects (optical imaging, SEM and TGA analysis). Further, plate load tests were conducted on unstabilized/MICP stabilized LMSF fill to understand the enhancement in load bearing capacity due to MICP treatment. The study noted that UCS values for 7, 14 and 21 cycles MICP stabilized LMSF are 7.95, 10.38 and 14.45 times higher than unstabilized LMSF. Further multi-fold increase in strain energy density is observed for MICP stabilized LMSF as compared to unstabilized LMSF. The plate load test results confirm about 119 % increase in the ultimate load bearing capacity of MICP stabilized LMSF as compared to unstabilized LMSF. The water stability test and microstructural studies affirm uniform/stable cementation in MICP stabilized LMSF. Overall, the study findings are favorable for exploring potential of biostabilized LMSF, as an environmentally friendly pathway for fill and other applications, a small contribution towards United Nations Sustainable Development Goals.