The solidification of heavy metal Pb2+-contaminated soil by enzyme-induced calcium carbonate precipitation combined with biochar

Biochemical Engineering Journal, Journal Year: 2024, Volume and Issue: 212, P. 109496 - 109496

Published: Sept. 17, 2024

Language: Английский

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Flowing-water remediation simulation experiments of lead-contaminated soil using UCB technology

International Journal of Phytoremediation, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 10

Published: Dec. 22, 2024

The flowing-water remediation of contaminated soil was investigated. Urease combined with biochar (UCB) technology used to handle the Pb

Language: Английский

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Optimizing Soil Stabilization with Chitosan: Investigating Acid Concentration, Temperature, and Long-Term Strength

Polymers, Journal Year: 2025, Volume and Issue: 17(2), P. 151 - 151

Published: Jan. 9, 2025

Civil and geotechnical researchers are searching for economical alternatives to replace traditional soil stabilizers such as cement, which have negative impacts on the environment. Chitosan biopolymer has shown its capacity efficiently minimize erosion, reduce hydraulic conductivity, adsorb heavy metals in that is contaminated. This research used unconfined compression strength (UCS) investigate impact of chitosan content, long-term assessment, acid concentration, temperature improvement strength. Static triaxial testing was employed evaluate shear treated soil. Overall, goal identify optimum values mentioned variables so highest potential chitosan-treated can be obtained applied future well large-scale applications engineering. The UCS results show increased over time at high temperatures. Depending type, a curing between 45 65 °C considered optimal. not soluble water, an solution needed dissolve biopolymer. Different ranges were investigated find appropriate amount. when concentration reached optimal level, 0.5-1%. A detailed chemical model developed express how affect properties biopolymer-treated SEM examination findings demonstrate covered particles filled void spaces. strengthened by formation hydrogen bonds electrostatic interactions with particles.

Language: Английский

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Investigation of desiccation cracking of earthen site soils treated by enzyme-induced calcium carbonate precipitation (EICP)

Biogeotechnics, Journal Year: 2025, Volume and Issue: unknown, P. 100166 - 100166

Published: Feb. 1, 2025

Language: Английский

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Effectiveness of microbial-induced carbonate precipitation for mitigating the hydraulic erosion of the riverbank

Journal of Environmental Management, Journal Year: 2025, Volume and Issue: 376, P. 124320 - 124320

Published: Feb. 10, 2025

Language: Английский

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Research on the Strength Properties and Microscopic Mechanism of Loess Stabilized by the Combined Use of MICP Technology and Plant Straw

Materials, Journal Year: 2025, Volume and Issue: 18(5), P. 992 - 992

Published: Feb. 24, 2025

There are many drawbacks in traditional loess-strengthening technology. MICP (microbially induced calcium carbonate precipitation) technology provides a new approach to loess management, but there few studies on solidification and lack of engineering application research verification. This study investigated the strength microscopic mechanisms solidified by combined with plant straw. The permeability conditions for were derived, multiple sets experiments conducted using specific loess, Bacillus pasteurii, cementing solution, straw, other materials. explored shear strength, unconfined compressive properties, growth adaptability, factors affecting bacterial growth. results indicated that within temperature range 25-35 °C, concentration urease activity pasteurii significantly affected temperature, highest observed at 30 °C. During scaled-up cultivation, increasing inoculation ratio prevented significant decrease individual strains, 1% was generally sufficient meet experimental requirements. When density 1.7 g/cm3 1.8 g/cm3, cohesive force internal friction angle groups added solution increased approximately 30% 50% 15% 5%, respectively, indicating can enhance loess.

Language: Английский

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Utilizing ARTP Mutagenized Calcifying Microorganisms to Drive Low-Urea Biocementation: Enhancing Strength and Reducing Ammonium Waste Emissions

Journal of environmental chemical engineering, Journal Year: 2025, Volume and Issue: unknown, P. 116923 - 116923

Published: May 1, 2025

Language: Английский

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Evaluation of dust fixation effect of urease-based biological dust suppressant and its field application

Journal of Environmental Management, Journal Year: 2024, Volume and Issue: 371, P. 123119 - 123119

Published: Nov. 1, 2024

Language: Английский

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Enhancing the Strength and Durability of Soil Using Sugarcane Molasses as Broth Medium in the Microbial-Induced Calcite Precipitation (MICP) Technique

Geomicrobiology Journal, Journal Year: 2024, Volume and Issue: unknown, P. 1 - 12

Published: Dec. 11, 2024

Microbial-induced calcite precipitation (MICP) is a promising, sustainable, and environmentally friendly ground improvement technique. This study examined the effectiveness of molasses (MS) as broth medium compared to nutrient (NB). Sporosarcina pasteurii was used in 0.5 M cementation solution with pore volumes (PV) 0.50, 0.75, 1 PV biotreatment cycles 9 18 days. Mechanical properties biotreated samples were assessed through unconfined compressive strength (UCS) split tensile (STS) tests, while content, scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDS) interpret biocementation. NB-treated exhibited significantly higher content than MS-treated samples. The durability under 6, 12, freeze-thaw (FT) revealed that FT cyclic process affects mechanical physical characteristics Samples treated for longer duration durability. mass losses NB MS 7–14.5% 15–32%, respectively, after cycles. Overall, exhibit While proved less effective MICP process, its cost-effectiveness abundant availability make it promising choice process.

Language: Английский

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Study on Mechanical Properties of Sandy Soil Solidified by Enzyme-Induced Calcium Carbonate Precipitation (EICP)

Buildings, Journal Year: 2024, Volume and Issue: 14(7), P. 1977 - 1977

Published: June 30, 2024

Earth–rock dams are widely distributed in China and play an important role flood control, water storage, water-level regulation, quality improvement. As emerging seepage control reinforcement technology the past few years, enzyme (urease)-induced calcium carbonate precipitation (EICP) has qualities of durability, environmental friendliness, great economic efficiency. For EICP-solidified standard sand, this study analyzes effect dry density, amount cementation, standing time, perfusion method, other factors on permeability strength characteristics solidified sandy soil by conducting a test unconfined compression then working out optimal solidification conditions EICP. Furthermore, quantitative relationship is established between coefficient (PC), compressive (UCS), CaCO3 generation (CG). The findings indicate that PC decreases UCS rises as starting time rise. With increase CG, while increases, indicating good correlation among PC, UCS, CG. condition EICP achieved two-stage grouting method with initial density 1.65 g/cm3, cementation 6 d, 5 d. Under such conditions, 6.25 × 10−4 cm/s, 1646.94 kPa. theoretical value scientific significance for guiding earth–rock dams.

Language: Английский

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