Saudi Cultural Missions Theses & Dissertations
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Item Restricted Modeling the Adsorption Behavior of Carbon Dioxide on Zeolites(Queen Mary University of London, 2024-08) Alturaiki, Ahmed; Shah, RazaThe increasing level of carbon dioxide in the atmosphere caused by fossil fuels consumption has incredibly contributed to climate change. Considering this issue requires a reduction in carbon dioxide emissions and developments in carbon capture technologies. Zeolites have been widely used as adsorbents in separation processes. The study of carbon dioxide adsorption behavior on zeolites has been significantly focused on due to its importance in carbon capture and storage applications due to their properties. The CO2 adsorption capacity and selectivity in zeolite are high which makes it a promising material to be utilized in separating CO2 from gas mixtures. This study investigates the adsorption behavior of zeolites 13X and 4A using molecular simulations. This experiment employs Grand Canonical Monte Carlo (GCMC) simulations to model CO2 adsorption behavior under varying conditions, integrating Coulomb and Lennard- Jones potentials to demonstrate particle interactions. Key aspects such as breakthrough curves, adsorption isotherms and the influence of pore size and cation exchange are discussed. Results indicate that zeolite 13X has a better CO2 adsorption performance compared to zeolite 4A. This research aims to provide insights into optimizing zeolite materials to be more cost-effective, efficient, and sustainable CO2 capture technologies in order to contribute to mitigating global warming.10 0Item Restricted BIOMASS-DERIVED GRAPHENE OXIDE (GO) SUPPORTED - METAL-ORGANIC FRAMEWORK (MOF) POLYANILINE- BASED NANOCOMPOSITE FOR THE REMOVAL OF HEAVY METALS IONS (Pb 2+, Ni 2+) IN WATER(Universiti Sains Malaysia, 2024-09) Alshammeri, Thamer Naif K; Ibrahim, Mohamad; Shahadat, MohamadThe global concern of contamination of heavy metals in water sources is significant. Industrial effluents, which contain pollutants, are released into water sources, hence increasing the probability of heavy metal toxicity in both humans and aquatic organisms. The current investigation focuses on developing a GO/PANI/MOF nanocomposite adsorbent. This nanocomposite is designed to effectively adsorb heavy metal ions (Pb2+ and Ni2+) from synthetic sample. The existence of functional groups, the material's crystallinity property, thermal stability, and surface area, were assessed using several techniques. Specifically, Fourier Transform Infrared Spectroscopy (FTIR) was utilized to identify functional groups, while X-ray diffraction (XRD) was employed to assess the material's crystalline structure, and thermal stability was assessed by thermogravimetric analysis (TGA). Scanning Electron Microscopy (SEM) was used to examine surface morphology. The current study investigated the different physiochemical parameters such as, adsorbent dose, contacting time, heavy metal ion concentration, pH, and temperature influence the adsorption of heavy metal ions. The GO/PANI/MOF-based nanocomposite was employed as an effective adsorbent for removing Pb²⁺ and Ni²⁺ ions. The GO/PANI/MOF-based nanocomposite showed its excellent efficiency at a pH of 6, with a dosage of adsorbent of 50 mg and a starting concentration of metal ions of 60 ppm for Pb2+ and 45 ppm for Ni2+ , respectively, at room temperature (25±2 °C). The equilibrium time required for Pb2+ was 90 min and 120 min for Ni2+. The optimum capacity for adsorption for Pb2+ was determined to be 50 mg/g and 42 mg/g for Ni2+. Furthermore, kinetic, isotherms, and thermodynamics studies were also investigated. This was observed in synthetic water sample. The GO/PANI/MOF nanocomposite has a high capacity for removing heavy metal ions from wastewater, making it a promising option for successful treatment. Keywords: Adsorption, wastewater treatment, GO/PANI/MOF nanocomposite, water pollution.4 0Item Restricted THORIUM REMOVAL FROM RARE EARTH INDUSTRIAL RESIDUE USING NATURAL AND MODIFIED ZEOLITES(Universiti Kebangsaan Malaysia, 2024-07-24) Alotaibi, Abdulrhman Masoud D; Ismail, Aznan Fazli BinThe rare-earth industries produce a significant quantity of radioactive residue that contains elevated thorium concentrations. Therefore, thorium removal from radioactive waste is regarded as a crucial issue in the treatment of such waste due to its radiotoxicity, chemical toxicity, and long half-life, which could potentially have adverse effects on the environment and human health. Furthermore, the removal of thorium from radioactive residues using appropriate treatments can reduce the amount of waste that needs to be disposed of. This study investigates the removal of thorium ions from synthetic thorium solutions and industrial rare earth residue known as Water Leach Purification (WLP) using natural and modified zeolites. The natural zeolite (clinoptilolite) was modified with sulphate and phosphate anions. The physical and chemical characterization of natural zeolite (NZ), phosphate-modified zeolite (PZ), and sulfate-modified zeolite (SZ) was conducted using various characterization techniques. Experiments were conducted in the laboratory to assess the suitability of the examined adsorbent materials for the removal of thorium. Adsorption of thorium from the aqueous solutions was investigated via a batch method. Furthermore, isotherm models, kinetic models, and other experimental parameters that affect the adsorption process were also investigated. The successful modification of NZ with sulfate and phosphate anions was confirmed through shifts observed in the Fourier-transformed infrared (FTIR). Furthermore, the energy dispersive X-Ray (EDX) analysis results unequivocally verified the presence of sulfate and phosphate elements in the structures of SZ and PZ, respectively. Findings proves that the modification to the surface of NZ has been successfully carried out. The modification of NZ reduced its specific surface area but increased its thorium adsorption capacity. The obtained results from the adsorption of thorium ions on NZ, PZ and SZ demonstrated that the investigated adsorbents were capable of removing thorium ions from aqueous solutions. The results indicated that the experimental maximum adsorption capacities of NZ, PZ, and SZ for thorium are found to be 12.7, 17.4, and 13.8 mg/g, respectively. The analysis of isotherms indicated that the Langmuir isotherm model provided the best fit to the experimental data. The modification of NZ with sulfate anions did not lead to a notable enhancement in its thorium ion adsorption capacity. In contrast, the adsorption capacity was significantly improved when it was modified with phosphate anions. The effect of experimental variables, including contact time, mass of the adsorbent, initial thorium concentration, and pH level of the solution, was scrutinized utilizing the batch mode method to identify the optimal adsorption conditions. The findings revealed that the best parameters for thorium adsorption included a 24-hour contact time, 0.03 grams of PZ, a pH of 3, and a temperature of 25°C. Studies on the kinetics of adsorption showed that the thorium adsorption onto PZ was a good fit for the pseudo-second-order model. The application of PZ to treat actual industrial rare earth residue (WLP) under optimized conditions demonstrated that almost complete thorium removal (> 99%) was achieved from the leached WLP solution. The results obtained indicated that PZ proved to be an exceptionally effective adsorbent material for thorium removal from real industrial rare earth residue using the adsorption method, leading to a decrease in waste volume for final disposal.41 0Item Unknown PALM OIL MILL EFFLUENT TREATMENT USING RICE HUSK-BASED ADSORBENT(Universiti Teknologi Malaysia, 2024) ALGHAMDI ABDULMAJEED HASEN A; Puteh, Mohd HafizThis study addresses the environmental challenges posed by the palm oil industry, specifically focusing on the mitigation of Palm Oil Mill Effluent (POME). The main aim of the research is to explore the efficiency and environmental impact of using rice husk-based adsorbents to treat POME. This involves comprehensive adsorption studies to assess the capacity of rice husk-based adsorbents in removing recalcitrant contaminants from POME, ultimately improving its quality. This study offers a sustainable and economically feasible treatment method for POME, addressing both environmental and industrial concerns. By transforming agricultural waste (rice husks) into a valuable resource for wastewater treatment, the research aligns with green chemistry principles and promotes circular economy practices. The study utilizes various surface modification techniques such as chemical functionalization and nanocomposite formation to enhance the performance of rice husk-based adsorbents. Experimental conditions were precisely defined, including the use of different pyrolysis temperatures, dosages, and pH levels, to optimize the adsorption process. The research also involved statistical analysis, including F-tests, to determine the significance of observed differences under varying conditions. The main findings indicate that rice husk-based biochar is effective in reducing Chemical Oxygen Demand (COD) and ammonia levels in POME. The optimal conditions for maximum pollutant removal were identified to be biochar produced at 800°C showed the highest overall removal efficiency. A dosage of 8 g/L was found to be the most effective for both COD and ammonia removal. The most acidic (pH 4) condition was favourable for COD removal, while ammonia removal remained consistently high across all pH levels, demonstrating that modified rice husk adsorbents can significantly improve the quality of treated POME. The study also revealed the importance of surface modifications in overcoming the inherent limitations of raw rice husk adsorbents. In conclusion, this study contributes to the field by providing a viable solution for POME treatment using rice husk-based adsorbents. It highlights the potential of agricultural waste as an effective and sustainable resource for wastewater treatment, paving the way for further innovations in environmental management.15 0Item Restricted Mathematical Modeling and Analysis of Competitive Adsorption of Multi-component PFAS and Reactive Transport of PFAA Precursors in the Vadose Zone(University of Arizona, 2024-08-07) Saleem, Hassan; Gupta, HoshinPer- and polyfluoroalkyl substances (PFAS) are synthetic chemicals widely used in industrial and consumer products for their unique resistance to water, oil, temperature, and chemical reactions. However, their persistence in the environment and potential for bioaccumulation pose significant risks to human health and ecosystems. The challenges and motivations for this dissertation arise from the need to fully address PFAS leaching and retention, which previous work has struggled with due to the complex mechanisms and dynamics of contaminant transport in the vadose zone. Additionally, the critical changes in flow regimes and surface tension modifications, caused by the multi-component adsorption of PFAS, present significant difficulties. Lastly, there is a crucial need to investigate the reaction transport phenomena of PFAS, specifically the transformation from degraded PFAA precursors, to better understand their environmental impact and develop effective remediation strategies. This dissertation consists of two studies xxx findings from two comprehensive studies to enhance the understanding of PFAS behavior in the vadose zone, a critical subsurface region influencing groundwater contamination. The first study develops a multi-component mathematical model to quantify the transport and retention of PFAS mixtures, highlighting the impact of competitive adsorption in varied soil types over long periods. The second study develops a detailed model to simulate the transformation and degradation of PFAS precursors, incorporating environmental and physicochemical factors to elucidate their long-term environmental impacts. Both studies employ advanced numerical modeling, combined with literature experimental data, to provide a robust framework for predicting PFAS transport and transformation. The findings emphasize the significant role of the vadose zone in retaining PFAS and the PFAAs precursors, the influence of soil properties and co-contaminants on PFAS behavior, and the necessity for site-specific remediation strategies. This dissertation research provides critical insights into developing effective remediation techniques, informing regulatory policies, mitigating the long-term impacts of PFAS contamination, and ultimately contributing to the protection of soil and groundwater resources.70 0Item Restricted ASSESSMENT OF IODINE REMOVAL EFFICIENCY OF SORBENT MATERIALS THROUGH BATCH AND CONTINUOUS FLOW EXPERIMENTS AND THEIR FORMULATION INTO CONSOLIDATION WASTE FORMS(Saudi Digital Library, 2023-11-23) Alghamdi, Turki; Rezaei, FatemeThe development of nuclear power has always been accompanied by the problem of the safe operation of nuclear power plants. This research focuses on iodine capture using MOFs, immobilization, and safe disposal were important issues for the development of nuclear power. In particular, several function materials were developed, formulated into different structures, and investigated for iodine capture and immobilization using gas or aqueous phase. Metal-organic frameworks (MOFs) were investigated thoroughly for iodine capture from off-gas streams; however, fewer studies have systematically investigated the performance and structure-property relationships of MOFs on iodine removal. In the first part of the research, Zr-UiO-66 and Ni-MOF-74 were successfully synthesized ad adsorbents for iodine in cyclohexane solution. Adsorption temperature, iodine concentration, and ion interference were investigated in the performance of iodine capture. Ni-MOF-74 outperformed Zr-UiO-66 in immobilizing iodine from the solution by achieving a maximum iodine removal efficiency of 97% at 60 °C Besides the results showed that the presence of other interfering ions marginally affects the iodine removal efficiency over both MOF sorbents. Then, continuous-flow experiments were conducted to assess the efficacy of these candidate adsorbents under more realistic conditions. The second part of the research focuses on addressing this issue by converting these iodine-laden MOFs into suitable waste consolidated forms for long-term disposal. Cement type III was used to solidify and stabilize the waste for disposal. The obtained findings show that the ability of the cement waste form to permanently trap iodine for safe geological disposal.20 0Item Restricted Recent Advancements in Graphene Oxide Adsorbents for Wastewater Treatment(Saudi Digital Library, 2023-10-02) Alyami, Hussain Hadi; Tahir, Asif; Roy, AnuragThe rapid increase in the world's population, alongside accelerated industrial expansion and the profound impacts of climate change, is intensifying the global water scarcity crisis. Graphene oxide (GO) and its varied composites play a pivotal role in wastewater purification, attributed to their superior adsorptive, oxidative, and catalytic properties. This review highlights the advances in hybrid graphene-based membrane materials, specifically engineered for water purification, addressing the growing demand for potable water. Intrinsically, graphene and GO and their composites boast a considerable pore volume, outstanding conductivity, diverse surface chemistry, and a remarkable aspect ratio. These attributes position them as ideal agents for the adsorption and catalysis of organic pollutants from wastewater. Notably, the sheet-like, resonant, polyaromatic π-system inherent in graphene derivatives facilitates critical interactions with organic pollutants, be it π–π stacking, hydrogen bonding, or electrostatic interactions. Such pollutants span from dyes and pharmaceutical by products to a spectrum of agricultural and industrial effluents. Many of these pollutants possess reactive unsaturated aromatic structures and abundant oxygen-rich functional groups. Numerous studies have meticulously analyzed the adsorption capacities of these pollutants, often framed within the context of established adsorption isotherm models such as Langmuir and Freundlich. Likewise, kinetic models, determinative factors, and the reusability of adsorbents have been thoroughly investigated. However, there's a noticeable gap in comprehensive dialogues comparing graphene-based membranes to other hybrid counterparts. Deepening our understanding of these graphene-infused membranes is crucial, marking a new paradigm in graphene applications. It is projected that upcoming research endeavors will further scrutinize and perfect the fabrication techniques of these cutting-edge graphene membranes, catalyzing more innovations in the sector.21 0Item Restricted CHITOSAN COMPOSITE BEADS FOR THE REMOVAL OF METHYLENE BLUE FROM AQUEOUS SOLUTION(2023-09-20) Alshammary, Sami; Anwar, MohammadChitosan-reinforced sodium alginate and bentonite (CS-SA-Ben) composite beads were synthesized using the ionic gelation method as biosorbents for the adsorption of methylene blue (MB) dye. The synthesized beads were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Thermal gravimetric analysis (TGA), and a digital microscope. The FTIR analyses indicate that the observed large peak at roughly 3420 cm-1 corresponds to hydroxyle (-OH) and amino (-NH2) stretching vibrations, showing the existence of these functional groups in chitosan. Chitosan's XRD pattern shows distinct peaks at specific diffraction angles, showing its crystalline structure. The digital microscope shows the size of the adsorbent, which is around 3916.21 μm. The batch adsorption method was carried out to illustrate the adsorptive capabilities of Chitosan-Sodium alginate-Bentonite in adsorbing MB. The highest adsorption of MB (88%) was achieved within 6 h when 400 mg of the biosorbent was used at 50 ˚C and pH 12 in a water bath shaker and stirred at a speed of 200 rpm. The adsorption is proposed to follow pseudo-second-order kinetics, with a linear regression coefficient (R2) of 0.982, demonstrating that MB followed the chemisorption mechanism. The Langmuir model was determined to better describe the adsorption process than the Freundlich model. Through the Langmuir isotherm, the maximum monolayer adsorption capacity (qmax) of the biosorbent was observed to be 48.94 mg/g under the optimum conditions. The CS-SA-Ben can be repeatedly used without losing its adsorptive capabilities.19 0