1. Preparation and research on cationic modified vermiculite with strong adsorption capacity for mineralizing bacteria.
- Author
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Wang, Zihang, Liu, Tianle, Yang, Guokun, and Zhao, Shitian
- Subjects
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VERMICULITE , *SCANNING electron microscopes , *ADSORPTION capacity , *THERMOGRAPHY , *CATIONIC surfactants - Abstract
• APTES and DETA were used for cationic modification of vermiculite. • Cationic modification vermiculite was positively charged in solution with PH <9.74. • Sporosarcina pasteurii was tightly adsorbed on the carrier due to the Coulomb force. • MICP treatment technology was applied to coarse sand reinforcement. To address the challenge of low binding strength and inefficient adsorption between mineralized bacteria carrier and microorganisms., this study aims to develop a novel immobilized carrier (Vermiculite/AP-DE) by modifying the surface of carrier with cationic modified material 3-aminopropyltriethoxysilane (APTES), and diethylenetriamine (DETA). The negatively charged Sporosarcina pasteurii (S.p) can be tightly adsorbed onto the carrier's surface through the Coulomb force, thereby improving the efficiency of microbial induced calcite precipitation (MICP). The FT-IR results and Zeta points analysis show that —NH 2 group was successfully introduced, and the carrier has a positive charge in the solution when pH < 9.74. Scanning electron microscope (SEM) images and Thermal gravimetric analyzer (TGA) results show that Vermiculite/AP-DE can tightly adsorb a large amount of microorganisms, and the calcite formation reached 30.5 % after MICP treatment, which is three times higher than traditional grouting materials. Sand reinforcement tests demonstrated that Vermiculite/AP-DE& S.p, as grouting material, exhibits a repair effectiveness on large-pore sand that surpasses traditional methods by more than threefold. This study provides a novel solution for MICP consolidation of coarse sand. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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