Biostimulation has been proven to be an available approach for microbially induced calcium carbonate precipitation(MICP).However,biostimulation may not be as effective as bioaugmentation in some unfavorable situations...Biostimulation has been proven to be an available approach for microbially induced calcium carbonate precipitation(MICP).However,biostimulation may not be as effective as bioaugmentation in some unfavorable situations.In this study,the feasibility of biochar-assisted MICP for improving the shear strength of calcareous sand is investigated.The optimization of cementation solution for biostimulated MICP is first determined through a series of unconfined compressive tests.The shear characteristics of biocemented calcareous sand,enhanced by biochar and treated through biostimulation,are then assessed using consolidated undrained(CU)shear triaxial tests.To characterize the shear strength of biocemented sand under low effective normal stress,both Mohr-Coulomb failure envelopes and nonlinear failure envelopes were employed.Meanwhile,the current study also compared and analyzed two distinct stress states:maximum principal stress ratio(σ'_(1)/σ'_(3)max)and Skempton’s pore pressure parameter A=0,to identify an appropriate failure criterion for determination of the shear strength parameters.Furthermore,the microscopic features and post-failure characteristics of biochar-assisted calcareous sand were examined and discussed.The findings indicate that biochar can contribute to an increase in cementation content by serving as additional nucleation sites.The study may provide valuable insights into the potential of biochar-assisted MICP for enhancing the biostimulation approach.展开更多
Microbially induced carbonate precipitation(MICP)is a new technology having the potential to induce soil stabilization and provide a green and sustainable comprehensive solution to some geotechnical engineering proble...Microbially induced carbonate precipitation(MICP)is a new technology having the potential to induce soil stabilization and provide a green and sustainable comprehensive solution to some geotechnical engineering problems in the environment.The present article is dedicated to present a critical review of this technology and discuss its mechanisms of action and the key factors influencing its performance.The global experiences and national participation from Egypt are demonstrated,in addition to attempts for real life applications.This review provides an insight into the practical steps taken to mitigate some of the current limitations of MICP application and the identified gaps in analogous studies.It was concluded that integrating MICP with existing technologies would favor both engineering needs and market requirements.In addition,providing effective solutions to MICP limitations would highlight this technology as an eco-friendly and cost-effective option to several engineering obstacles.Finally,recommendations focused on encouraging global collaboration for knowledge transfer about this technology among different countries,as well as positive financial support from industrial entities to aid in the progress of scientific research and achieving large-scale applications in the near future,are provided.展开更多
基金financially supported by the Natural Science Foundation of China(Grant Nos.42377166 and 42007246)Key R&D Program Social Development Project of Jiangsu Province(Grant No.BE2023800)the National Key R&D Program of China(Grant No.2023YFC3709600).
文摘Biostimulation has been proven to be an available approach for microbially induced calcium carbonate precipitation(MICP).However,biostimulation may not be as effective as bioaugmentation in some unfavorable situations.In this study,the feasibility of biochar-assisted MICP for improving the shear strength of calcareous sand is investigated.The optimization of cementation solution for biostimulated MICP is first determined through a series of unconfined compressive tests.The shear characteristics of biocemented calcareous sand,enhanced by biochar and treated through biostimulation,are then assessed using consolidated undrained(CU)shear triaxial tests.To characterize the shear strength of biocemented sand under low effective normal stress,both Mohr-Coulomb failure envelopes and nonlinear failure envelopes were employed.Meanwhile,the current study also compared and analyzed two distinct stress states:maximum principal stress ratio(σ'_(1)/σ'_(3)max)and Skempton’s pore pressure parameter A=0,to identify an appropriate failure criterion for determination of the shear strength parameters.Furthermore,the microscopic features and post-failure characteristics of biochar-assisted calcareous sand were examined and discussed.The findings indicate that biochar can contribute to an increase in cementation content by serving as additional nucleation sites.The study may provide valuable insights into the potential of biochar-assisted MICP for enhancing the biostimulation approach.
文摘Microbially induced carbonate precipitation(MICP)is a new technology having the potential to induce soil stabilization and provide a green and sustainable comprehensive solution to some geotechnical engineering problems in the environment.The present article is dedicated to present a critical review of this technology and discuss its mechanisms of action and the key factors influencing its performance.The global experiences and national participation from Egypt are demonstrated,in addition to attempts for real life applications.This review provides an insight into the practical steps taken to mitigate some of the current limitations of MICP application and the identified gaps in analogous studies.It was concluded that integrating MICP with existing technologies would favor both engineering needs and market requirements.In addition,providing effective solutions to MICP limitations would highlight this technology as an eco-friendly and cost-effective option to several engineering obstacles.Finally,recommendations focused on encouraging global collaboration for knowledge transfer about this technology among different countries,as well as positive financial support from industrial entities to aid in the progress of scientific research and achieving large-scale applications in the near future,are provided.
