Mature fine tailings consolidation through microbial induced calcium carbonate precipitation

2015 ◽  
Vol 42 (11) ◽  
pp. 975-978 ◽  
Author(s):  
Jiaming Liang ◽  
Zhengyang Guo ◽  
Lijun Deng ◽  
Yang Liu
Keyword(s):  
Electron Microscopy ◽  
Shear Strength ◽  
Undrained Shear Strength ◽  
Carbonate Precipitation ◽  
Calcium Carbonate Precipitation ◽  
Calcite Precipitation ◽  
Mature Fine Tailings ◽  
Fine Tailings ◽  
Undrained Shear ◽  
Scanning Electron

The performance and mechanisms of a microbial induced calcite precipitation (MICP)-assisted mature fine tailings (MFT) consolidation method was assessed. Mature fine tailings samples of 35 wt% and 60 wt% were treated with MICP by ureolysis. The undrained shear strength of treated MFT was measured to evaluate the effects of MICP on MFT consolidation. To investigate the surface interaction mechanisms involved in the process, the size and shape of MFT particles were observed using scanning electron microscopy. The results showed that ureolysis-driven MICP can accelerate raw MFT consolidation, leaving compact sludge with significantly enhanced shear strength within 24 h of the experiment.

scholarly journals Potential of fungi to produce bioconcrete

2020 ◽  
Vol 5 ◽  
pp. 157-162
Author(s):  
Carolina Martuscelli ◽  
Célia Soares ◽  
Nelson Lima ◽  
Aires Camões
Keyword(s):  
Electron Microscopy ◽  
Penicillium Chrysogenum ◽  
Chemical Constituents ◽  
Carbonate Precipitation ◽  
Self Healing ◽  
Calcium Carbonate Precipitation ◽  
Sustainable Solutions ◽  
Induction Process ◽  
Potential Use ◽  
Scanning Electron

The cracks in concrete reduce their resistance capacity and allow the entry of harmful agents both for their microstructure and for the reinforcements located inside the structure. Several studies have been done to promote sustainable solutions for this problem. The microbiologically induced calcium carbonate precipitation (MICCP) is an alternative to traditionally used methods and a way to reduce the environmental impact of using more cement and polymers. Most of the biocementation studies to fill cracks or to promote bio self-healing on concrete present bacteria as the microorganisms responsible for the CaCO3 induction process. Fungi are potentially better for the biocementation process because they have more biomass and some develop filaments that can be used as microfibers on materials. Thus, the present work proposes the development of a methodology to analyse the potential use of two urease-positive fungi (Penicillium chrysogenum MUM 9743 and Neurospora crassa MUM 9208) to produce bioconcrete. The microstructure and chemical constituents of biocrystals formed due to MICCP were observed under Scanning Electron Microscopy (SEM). SEM showed fungal mycelia as bio-based fiber in bioconcrete and clusters of probable calcite crystals on and around mycelia. Both fungi were able to promote biocimentation of sand.

scholarly journals Evaluation of Undrained Shear Strength of Miocene Clay from the Weight Sounding Test (WST)

2017 ◽  
Vol 62 (2) ◽  
pp. 367-384
Author(s):  
Sebastian Olesiak
Keyword(s):  
Shear Strength ◽  
Field Testing ◽  
Field Investigation ◽  
Undrained Shear Strength ◽  
Cohesive Soils ◽  
Strength Parameters ◽  
Additional Measurement ◽  
Carpathian Foredeep ◽  
Innovative Solution ◽  
Undrained Shear

Abstract Soil strength parameters needed for the calculation of bearing capacity and stability are increasingly determined from field testing. This paper presents a method to determine the undrained shear strength cuWST of the soil, based on the Weight Sounding Test (WST). The innovative solution which allows for a significant reduction of equipment needed for geotechnical field investigation is presented. The proposed method is based on an additional measurement of the torque during testing. It then becomes possible to estimate the undrained shear strength, cuWST of the soil, using the correlation given in this paper. The research results presented in this paper were carried out on selected cohesive soils, Miocene clays from the Carpathian Foredeep.

Sign in / Sign up

Export Citation Format

Share Document