Reduction of hydraulic conductivity of sand using combination of microbially produced and chemical source of ferrous cations

Abstract

ABSTRACT Biogeotechnology, is one of the most notable methods of soil improvement techniques. Along with the use of calcium-based biocement, the probability of using an inventive approach through the iron salts precipitation was also investigated. The present study discussed the feasibility of iron-based biocement using the combination of chemically and microbially source of ferrous cations. The method was introduced as an economical and green method using a cheap and accessible source of iron ore. A biocement treatment test via iron-based process was used to investigate the suitability of using three methods to improve geotechnical properties of loose sand and determine their respective hydraulic conductivity. The results of this study demonstrated that 1% of cation salts in sand was sufficient to reduce the hydraulic conductivity to 10−7 m/s as the bioclogging was performed mainly in the channels between sand particles. Moreover, the precipitation of iron salts was also seen between sand grains in the SEM images.