http://yetl.yabesh.ir/yetl1/handle/yetl/19003 Tue, 28 Apr 2026 11:51:14 GMT 2026-04-28T11:51:14Z http://localhost:80/yetl1/bitstream/id/184298/ http://yetl.yabesh.ir/yetl1/handle/yetl/19003 http://yetl.yabesh.ir/yetl1/handle/yetl/4309545 Physical and Chemical Investigation of Crude Oil Adsorption Using Bentonite Nanofluid in Contaminated Bushehr Carbonate Sand Masoud Nasiri; Ehsan Amiri Guaranteeing the civil engineering structures’ safety around oil wells is a crucial problem in civil and environmental engineering. The spillage of crude oil (CO) in soils leads to an intense decline in strength, causing severe ecosystem catastrophes. This matter is critical for oil-rich nations, such as Iran, with numerous CO resources. This study performs precise chemical analysis and cyclic and static simple shear tests (SSTs) on Bushehr carbonate sand (BCS). Since the dynamic resistance of carbonate sand (CS) is significantly different from quartz sand, this study investigates the CO-contaminated BCS. This investigation introduced a novel method for CO adsorption from contaminated carbonate sand. Bentonite nanofluid (BNF) is a novel soil treatment agent that considerably enhances the CO-contaminated BCS strength. The relative density of BCS specimens for SST was 60%, and CO in contaminated BCS samples was 6wt% (designated contamination level). This purpose was to explore the influence of CO contamination and the efficiency of an environmentally friendly stabilizer known as BNF, aiming to encounter polluted areas. Four different natural bentonites were studied to obtain the optimum type for preparing BNF. This paper uses SST (in static and cyclic states), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope, and X-ray diffraction analysis. The optimal CO-adsorption was 6wt% of BNF. Using BNF (as a novel treatment agent presented in this paper) causes approximately 20% and 17% increases in dynamic and static strengths of CO-contaminated BCS. The FTIR analysis confirmed the physical experiments and indicated that the peak of the C–H bond is remarkably declining due to the high efficiency of this novel technique in crude oil adsorption. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4309545 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309544 Pyrolysis of Sodium Dibutyl Phosphate–Laden Radioactive Liquid Waste Selvakumar Jayaprakasam; Raghukumar Pookattil; Sourav Maity; Kumari Anshul; Srinivasan Subramanian; Srinivasa Rao Gadiraju; Gayen Jayantha Kumar Alkaline hydrolysis of organic radioactive liquid waste, specifically, spent PUREX solvent, is an established process that yields three distinct phases: n-dodecane (top), water-soluble organic phosphate (dibutyl phosphate) along with butanol (middle, a product of alkaline hydrolysis), and unreacted alkali (bottom). Managing the middle layer (ML) poses significant challenges due to its high phosphate content (300–350 g/L), substantial radioactivity (gross α 515–1,500 Bq/mL, gross β-γ 1,453–2,500 Bq/mL), and complex composition. Various methodologies have been tested to destroy organic components or separate radionuclides from the ML, including dilution and dispersion, microfiltration, direct cementation, chemical precipitation, and pyrolysis. Among these methods, pyrolysis has successfully demonstrated complete mineralization, converting sodium dibutyl phosphate to Na3PO4 and effectively separating and isolating the radioactive content from the ML using an indigenously designed pyrolyzer. In this work, comprehensive studies on the thermal, spectroscopic, and radiometric properties of the ML, as well as the immobilization of residues, were conducted by employing a thermogravimetry analyzer (TG-DSC) coupled with an evolved gas analyzer, Fourier-transform infrared spectroscopy, high-purity germanium (HP-Ge) gamma (γ) spectrometry, and the International Atomic Energy Agency (IAEA) 28-day chemical durability test. The resulting cement waste form contained 20 wt% undissolved residue from ML pyrolysis and separated radionuclides achieved a leachability index (L) greater than 6. This indicates that the cemented waste form meets the acceptance criteria, ensuring safe and effective long-term disposal. The combination of alkaline hydrolysis (AH) and pyrolysis presents an effective method for managing organic radioactive liquid waste (OLW) from spent PUREX solvent in reprocessing plants. AH separates the waste into three layers, with the middle layer (ML) containing high levels of dibutyl phosphate (DBP) and radioactivity. Pyrolysis of the ML in an inert atmosphere successfully mineralizes Na-DBP to Na3PO4 and isolates radioactive content. Thermogravimetric, spectroscopic, and radiometric analyses confirmed the complete degradation of DBP and the formation of nontoxic by-products. The residue from pyrolysis, containing radionuclides, was immobilized in a cement waste form with a leachability index greater than 6, meeting disposal criteria. This process, demonstrated in lab scale, ensures efficient treatment of OLW. The organic layer from pyrolysis can be incinerated, while the aqueous layer is mixed with low-level waste for disposal. The conditioned cement waste form ensures safe, long-term disposal, offering a comprehensive solution for OLW management with regulatory compliance and minimal environmental impact. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4309544 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309542 Influence of Microbially Induced Calcite Precipitation Technique on Mitigating Rainfall-Induced Surface Erosion of the Ganga River Sand Abhishek Tarun; Arvind Kumar Jha Microbially induced calcite precipitation (MICP) is an emerging field of microbial geotechnology for surface erosion remediation. Conventionally, Sporosarcian pasteurii bacteria are used mostly for MICP treatment to enhance the soil properties. However, the potential of other urease-producing bacteria on surface erosion prevention is underexplored and, hence, needs a detailed investigation. Further, the insight into the exposure of MICP-treated surfaces to field conditions like natural rainwater and acid rain has not been explored. In the present study, different surface models of Ganga River Sand (GRS) were prepared at 70% relative density and inoculated with three different soil bacteria, i.e., Bacillus sp., Bacillus sphaericus, and Bacillus subtilis. Samples were then treated for 10 days with the cementation solution (0.7 M CaCl2 and urea). Later, these samples were subjected to microanalysis and controlled rainfall conditions. To study the effects of natural rainfall, the rainwater parameters and rainfall intensity were kept closer to the natural conditions. Further, the durability of the biotreated GRS surface was checked against simulated acidic rainfall at a surface slope angle of 45° to examine the stability of the treated surface in unfavorable conditions. Moreover, the change in biochemical properties of the rainwater after erosion was also examined alongside the erosion rate, erosion pattern, and strength of the treated GRS surface. The sand surfaces showed an enhanced rainfall-induced erosion resistance after the MICP treatment. B. sphaericus has shown better erosion resistance performance than the other two selected bacteria in terms of effectiveness and durability. A surface strength of 612 kPa was observed for the samples inoculated with B. sphaericus . It is also revealed that MICP-treated surfaces have pronounced poor durability subjected to acid rain. Despite the effectiveness demonstrated by the MICP treatment process in surface erosion resistance, an effort toward optimization and environmental considerations should be addressed before the process is upscaled. Bioremediation of ground through the MICP process is a topic of contemporary research. It includes the augmentation of biotechnology in the geotechnical engineering field for a green, sustainable, and eco-friendly approach to ground improvement. This process eliminates the conventional use of higher energy consumption processes and harmful chemicals for surface and ground improvement. Bio-cementation has been a captivating method among researchers for soil erosion control. This process relies on the calcite byproduct for its effectiveness, which is a relatively stable compound. The performance of the MICP-treated soil surface shows promising results in erosion control with this environment-friendly approach. The problem arises when the field condition becomes unfavorable for calcite crystals, making the MICP-treated surfaces vulnerable to external agents like rainfall, freeze and thaw, wetting and drying, and so on. The goal of this study is to address and propose the risks associated with the culpability of calcite deterioration upon exposure to field conditions like rainfall. Further, this study implores the research community to address the calcite stability in adverse conditions before the large-scale application of the MICP treatment process. The sustainability and longevity of MICP-treated surfaces should be a major concern before its widespread application to prevent any catastrophic event that may arise due to the propensity of cementation material. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4309542 2025-01-01T00:00:00Z http://yetl.yabesh.ir/yetl1/handle/yetl/4309541 Interplay of Dye Biodegradation and Energy Recovery in a Microbial Fuel Cell with a MnO₂-Modified Anode under Optimized Conditions Kalpana Sharma; Ankit Kumar; Soumya Pandit; Vandana Singh; Dipak A. Jadhav In microbial fuel cells (MFCs), Klebsiella pneumoniae and Pseudomonas aeruginosa bacterial coculture was used to generate energy and to degrade various concentrations of malachite green (MG) dye. The performance of MFCs was examined using electrochemical techniques under variation in operating conditions. During operation, K. pneumoniae can degrade 98.4% dye after a 36-h incubation period at pH 7 under an optimized MG concentration of 200 mg/L. A maximum power of 8.2 W/m3 was attained by 1:1 coculture of Klebsiella pneumoniae and Pseudomonas aeruginosa at 200 mg/L MG concentration. Anode modification with 2 mg/cm2 manganese dioxide (MnO2) loading showed an improvement in surface area and enhancement of electron transfer, which resulted in a power density of 12.6 W/m3. The electrochemical analysis also supported improvement in electrogenic biofilm development and electron transfer with anode modification, which can be suitable for the long-term operation of MFCs. Therefore, the interplay of dye removal and energy recovery can be optimized with process parameters and anode modification in MFCs. Microbial fuel cells (MFCs) utilizing a coculture of Klebsiella pneumoniae and Pseudomonas aeruginosa offer a practical solution for degrading toxic dyes like malachite green in industrial wastewater while simultaneously generating electricity. This approach is particularly effective with the use of MnO2-modified anodes, which significantly improve electron transfer efficiency during the microbial degradation process. MnO2 nanoparticles provide a conducive surface for bacterial biofilm formation and facilitate effective electron flow from the dye degradation reactions to the anode. As a result, the MFC not only breaks down malachite green into nontoxic by-products, reducing environmental pollution, but also captures the released electrons to produce electricity. This dual functionality makes MFCs an attractive option for industries looking to implement sustainable wastewater treatment solutions. By integrating MFC technology with existing wastewater treatment systems, industries can achieve effective dye removal, while offsetting energy costs through the electricity generated, thereby enhancing both environmental and economic sustainability. Wed, 01 Jan 2025 00:00:00 GMT http://yetl.yabesh.ir/yetl1/handle/yetl/4309541 2025-01-01T00:00:00Z