Date of Defense
27-11-2025 1:00 PM
Location
F3-136
Document Type
Dissertation Defense
Degree Name
Doctor of Philosophy in Architectural Engineering
College
COE
Department
Architectural Engineering
First Advisor
Dr. Maatouk Khoukhi
Keywords
purification media, CO2 adsorption, agricultural waste, indoor environment, occupant health, RSM optimization, ANSYS optimization, optimal parameters.
Abstract
Indoor environments are crucial for human activity, as people spend over 90% of their time indoors. This extensive indoor presence makes these spaces crucial for overall well-being. The growing awareness of Indoor Air Quality's (IAQ) impact on health, productivity, and wellness contrasts with buildings' contributions to greenhouse gas emissions, particularly through construction materials such as exterior walls, upper floors, and interior finishes. Classrooms are especially concerning because they house many students who are exposed to indoor air pollutants for extended periods. Given the significance of IAQ in educational settings, there is an urgent need for effective solutions to improve air quality. Additionally, the United Arab Emirates (UAE) faces a significant environmental challenge, as nearly 40% of imported rice is wasted each year. However, this waste also presents an overlooked opportunity for sustainable resource development.
This research aims to develop and optimize a purification medium made from waste rice, with a focus on reducing carbon dioxide (CO₂) levels in classrooms. Lowering CO₂ is essential for enhancing student well-being, learning quality, and cognitive performance. The material’s effectiveness was systematically evaluated through a comprehensive assessment, including structural analysis, detailed examination of its morphological properties, and testing of its CO₂ reduction efficiency. This study is grounded in a comprehensive and systematic research framework aimed at evaluating and optimizing the performance of a novel bio-based purification material. The material, developed from treated puffed rice media, is designed to enhance indoor air quality (IAQ) through the passive reduction of CO₂.. The methodology combines experimental approaches, chemical functionalization, and optimization techniques, followed by simulation modeling, to ensure both effectiveness and applicability in a real-world indoor environment. This study demonstrates the practicality of integrating waste byproducts into sustainable technologies, showcasing potential future applications in various indoor environments. The experimental findings revealed that optimizing the puffing conditions of rice, specifically at 18% moisture content and 260 °C, yielded the greatest expansion, producing a thickness of approximately 1.2 cm with enhanced porosity suitable for gas adsorption. To further improve performance, the material was chemically functionalized using sodium hydroxide (NaOH). FTIR, TGA, and XRD analyses confirmed that NaOH treatment significantly enhanced the surface chemistry, thermal stability, and crystalline structure of the puffed rice media, thereby improving its suitability for CO₂ capture at typical indoor operational temperatures. SEM imaging supported these results by revealing improved pore structure and connectivity in treated samples. Performance testing demonstrated that puffed rice media treated with 2.0 M NaOH achieved the highest adsorption capacity, removing approximately 0.37 mol of CO₂ (38%) under laboratory-scale testing. Geometric optimization showed that circular purification discs provided superior uniformity, stability, and ease of integration compared to square or cuboid forms, making them practical for wall- or ceiling-mounted systems. These discs can be produced in several dimensions and colors, allowing architectural adaptability and seamless integration into indoor spaces. Controlled chamber experiments applying the real indoor environment confirmed that CO₂ reduction efficiency was strongly influenced by temperature, relative humidity, and material coverage, with the optimal condition (25 °C, 55% RH, 45% coverage) reducing CO₂ concentration from 1001 ppm to 684 ppm within the tested period, with an average reduction rate of 79.25 ppm/hr. Statistical modeling using Response Surface Methodology (RSM) and ANOVA demonstrated strong predictive capability (R² = 97.38%, adj. R² = 94.42%) and identified material coverage as the most significant factor. The model predicted a maximum uptake of 312.1 ppm under optimal conditions with high desirability (0.9766). Long-term extrapolation using kinetic modeling further indicated sustained adsorption capacity, with saturation projected after approximately 2.1 years of continuous daily operation. Additionally, the material’s versatility in shape and color allows for various design applications, making it suitable for different architectural and decorative purposes. It is easy to implement while remaining sustainable and eco-friendly. Compared to conventional materials such as coconut-shell activated carbon or bamboo-based carbon, which require high-temperature activation (>800 °C) and exist mainly in granular or powdered forms, the puffed rice media demonstrates equivalent adsorption potential through a low-temperature process and easily deployable disc-shaped geometry. This highlights its competitive advantage for passive, surface-based purification systems in indoor environments. This study demonstrates that chemically modified puffed rice media represents a practical, sustainable, and scalable solution for reducing CO₂ in classrooms and similar indoor spaces. It combines effective adsorption performance with low energy requirements, aesthetic adaptability, and long operational life, making it a promising innovation for both indoor air quality improvement and sustainable waste utilization in the built environment. The findings present a distinctive strategy for reducing indoor CO₂ levels, aligning with global efforts to foster sustainability and resource efficiency in construction practices.
Included in
DEVELOPMENT AND EXPERIMENTAL VALIDATION OF A BIO-BASED CO2 PURIFICATION MEDIUM DERIVED FROM PUFFED RICE WASTE FOR INDOOR AIR QUALITY IMPROVEMENT
F3-136
Indoor environments are crucial for human activity, as people spend over 90% of their time indoors. This extensive indoor presence makes these spaces crucial for overall well-being. The growing awareness of Indoor Air Quality's (IAQ) impact on health, productivity, and wellness contrasts with buildings' contributions to greenhouse gas emissions, particularly through construction materials such as exterior walls, upper floors, and interior finishes. Classrooms are especially concerning because they house many students who are exposed to indoor air pollutants for extended periods. Given the significance of IAQ in educational settings, there is an urgent need for effective solutions to improve air quality. Additionally, the United Arab Emirates (UAE) faces a significant environmental challenge, as nearly 40% of imported rice is wasted each year. However, this waste also presents an overlooked opportunity for sustainable resource development.
This research aims to develop and optimize a purification medium made from waste rice, with a focus on reducing carbon dioxide (CO₂) levels in classrooms. Lowering CO₂ is essential for enhancing student well-being, learning quality, and cognitive performance. The material’s effectiveness was systematically evaluated through a comprehensive assessment, including structural analysis, detailed examination of its morphological properties, and testing of its CO₂ reduction efficiency. This study is grounded in a comprehensive and systematic research framework aimed at evaluating and optimizing the performance of a novel bio-based purification material. The material, developed from treated puffed rice media, is designed to enhance indoor air quality (IAQ) through the passive reduction of CO₂.. The methodology combines experimental approaches, chemical functionalization, and optimization techniques, followed by simulation modeling, to ensure both effectiveness and applicability in a real-world indoor environment. This study demonstrates the practicality of integrating waste byproducts into sustainable technologies, showcasing potential future applications in various indoor environments. The experimental findings revealed that optimizing the puffing conditions of rice, specifically at 18% moisture content and 260 °C, yielded the greatest expansion, producing a thickness of approximately 1.2 cm with enhanced porosity suitable for gas adsorption. To further improve performance, the material was chemically functionalized using sodium hydroxide (NaOH). FTIR, TGA, and XRD analyses confirmed that NaOH treatment significantly enhanced the surface chemistry, thermal stability, and crystalline structure of the puffed rice media, thereby improving its suitability for CO₂ capture at typical indoor operational temperatures. SEM imaging supported these results by revealing improved pore structure and connectivity in treated samples. Performance testing demonstrated that puffed rice media treated with 2.0 M NaOH achieved the highest adsorption capacity, removing approximately 0.37 mol of CO₂ (38%) under laboratory-scale testing. Geometric optimization showed that circular purification discs provided superior uniformity, stability, and ease of integration compared to square or cuboid forms, making them practical for wall- or ceiling-mounted systems. These discs can be produced in several dimensions and colors, allowing architectural adaptability and seamless integration into indoor spaces. Controlled chamber experiments applying the real indoor environment confirmed that CO₂ reduction efficiency was strongly influenced by temperature, relative humidity, and material coverage, with the optimal condition (25 °C, 55% RH, 45% coverage) reducing CO₂ concentration from 1001 ppm to 684 ppm within the tested period, with an average reduction rate of 79.25 ppm/hr. Statistical modeling using Response Surface Methodology (RSM) and ANOVA demonstrated strong predictive capability (R² = 97.38%, adj. R² = 94.42%) and identified material coverage as the most significant factor. The model predicted a maximum uptake of 312.1 ppm under optimal conditions with high desirability (0.9766). Long-term extrapolation using kinetic modeling further indicated sustained adsorption capacity, with saturation projected after approximately 2.1 years of continuous daily operation. Additionally, the material’s versatility in shape and color allows for various design applications, making it suitable for different architectural and decorative purposes. It is easy to implement while remaining sustainable and eco-friendly. Compared to conventional materials such as coconut-shell activated carbon or bamboo-based carbon, which require high-temperature activation (>800 °C) and exist mainly in granular or powdered forms, the puffed rice media demonstrates equivalent adsorption potential through a low-temperature process and easily deployable disc-shaped geometry. This highlights its competitive advantage for passive, surface-based purification systems in indoor environments. This study demonstrates that chemically modified puffed rice media represents a practical, sustainable, and scalable solution for reducing CO₂ in classrooms and similar indoor spaces. It combines effective adsorption performance with low energy requirements, aesthetic adaptability, and long operational life, making it a promising innovation for both indoor air quality improvement and sustainable waste utilization in the built environment. The findings present a distinctive strategy for reducing indoor CO₂ levels, aligning with global efforts to foster sustainability and resource efficiency in construction practices.