Sugarcane Molasses: A Cheap Carbon Source for Calcite Production in Different Class of Soils using Stimulation of Indigenous Urease-producing Bacteria

Abstract

In this research, we investigated the abilities of three different concentration of sugarcane molasses as a carbon source to stimulate indigenous bacterial growth in different classes of soil, namely poorly graded sand (SP), silty sand (SM), and clayey sand (SC) (according to the Unified classification system). A total of 7, 10, and 15 days after the treatment, direct shear tests were performed on the untreated and treated samples. The calcite content on all direct shear samples was determined to further correlate it with the strength gains in the treated samples. The scanning electron microscopy (SEM) images, EDX analysis, and X-ray diffraction (XRD) patterns were taken before and after treatment for all samples to analyze the microbial-induced calcite precipitation (MICP) process. The SP soil samples showed the highest strength gains and also highest calcite content as compared with other two soil type. The peak cohesion intercept for SP-treated samples increased by 2.7–5.5 times as compared to the untreated samples for molasses concentration of 1–3 g/L, respectively. The treated samples became more dilative with the increase in molasses concentration. The sample with highest molasses concentration showed stiffer behavior in shear than the samples with lower concentration.

Keywords:

• Bio-stimulation
• calcite
• direct shear
• Indigenous bacteria
• molasses

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The current study was supported by a grant No. [SCU.EC98,617] of the vice chancellor for research postgraduate administration of Shahid Chamran University of Ahvaz.