Factors Affecting Calcite Bio-precipitation via Urea Hydrolyzing Bacterial Consortium | ||
| Advances in Environmental and Life Sciences | ||
| Volume 2, Issue 2, October 2022, Pages 32-43 PDF (8.16 M) | ||
| Document Type: Original research articles | ||
| DOI: 10.21608/aels.2022.165065.1020 | ||
| Authors | ||
| Maha Taha Abdelgalil* 1; Salah Shata1; Heba Taher2; Hesham Abdulla1 | ||
| 1Botany and Microbiology Department Faculty of Science, Suez Canal University, Egypt | ||
| 2Geology Department Faculty of Science, Suez Canal University, Egypt | ||
| Abstract | ||
| Microbially induced calcite precipitation (MICP) refers to the biomineralization process involving the synthesizing of calcium carbonate by microorganisms. The production of urease by urea-hydrolyzing bacteria, which results in carbonate precipitation, is affected by environmental factors including calcium concentration, bacterial concentration, pH and temperature. This study aims to investigate some factors affecting calcite bio-precipitation via the urea-hydrolyzing consortium. A consortium of three urease-positive, calcite-precipitating strains of Bacillus was selected. XRD analysis of the precipitant confirmed the polymorph type. The studied factors included bacterial cell count, pH, temperature, urea concentration, and calcium concentration. In order to identify the optimum range of each studied factor, the dry weight of the precipitated calcite was measured for all investigated ranges of the studied factors after two weeks of incubation gravimetrically. A multi-level factorial experiment was designed to investigate the impact of interaction between different levels of factors using the statistical software package MINITAB 17. Three main factors were selected, bacterial cell count, urea and calcium concentration. The fourth run, among twelve runs of a multi-level designed experiment, which had the following concentrations (0.3 M urea, 15 g/l CaCl2.H2O, and low bacterial inoculum (105 CFU/50ml)), precipitated 0.43 g of calcite, while the rest of the runs precipitated lower dry weights. It was found that there was no significant increase in the precipitated calcite weight for the performed runs. According to the analysis of factorial design results, the effect of urea concentration as a factor on precipitation rate in the current study was found to be more effective than other studied factors. | ||
| Keywords | ||
| MICCP; Bio-mineralization; Bacillus - Urease | ||
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