Busitema University Lecturer Dr. Wangi Godfrey Mario Earns PhD, Develops Advanced Nanocomposite for Clean Water
Access to safe drinking water remains a persistent challenge in many low-resource communities across Uganda, where conventional treatment systems are often expensive, complex, or ineffective. Addressing this critical issue, Dr. Wangi Godfrey Mario, a lecturer in the Faculty of Engineering and Technology at Busitema University, has been awarded a PhD in Water Resources Engineering from Makerere University. His groundbreaking research focuses on developing zeolite-based nanocomposite materials capable of removing toxic metals and harmful bacteria from water, offering a promising solution for decentralized water treatment.
Dr. Wangi’s study emerged from the urgent need for affordable and effective water purification technologies, particularly in rural and peri-urban settings. While natural zeolites, a type of porous mineral are widely available in Uganda and other regions, their native properties alone are often insufficient for efficiently removing chemical and microbial contaminants. Recognizing this limitation, Dr. Wangi combined advances in nanotechnology and material science to create a silver-zeolite-polyethylene glycol (PEG) nanocomposite, designed to simultaneously adsorb heavy metals like lead and disinfect water contaminated with Escherichia coli (E. coli).
The research was both rigorous and comprehensive. It began with characterization of natural zeolites using X-ray diffraction (XRD), scanning electron microscopy (SEM), and BET analyses to understand their mineral composition and morphology. Key processing parameters such as milling speed, milling time, and ball-to-powder ratio were optimized using Response Surface Methodology (RSM), enhancing the surface area and uniformity of the zeolite powders critical factors for maximizing adsorption and antibacterial activity.
Next, Dr. Wangi synthesized the silver-zeolite-PEG nanocomposite through wet impregnation, carefully optimizing PEG content, reaction temperature, and time. The resulting material demonstrated dual functionality: it effectively adsorbed toxic metals while eliminating harmful bacteria from water. Laboratory tests showed that the nanocomposite achieved a lead adsorption capacity of 176.7 mg/g and completely disinfected water from a protected spring of E. coli in less than 60 minutes. The material also exhibited strong antibacterial efficacy against E. coli in culture, with a minimum inhibitory concentration (MIC) as low as 0.031 mg/mL, and a high adsorption capacity for methylene blue dye, a standard proxy for water contaminants.
Beyond laboratory performance, the research emphasizes reusability and scalability, key considerations for real-world deployment. The optimized silver-zeolite-PEG nanocomposite offers the potential for affordable, small-scale water treatment units, particularly in rural villages or emergency settings where access to clean water is limited. Dr. Wangi’s work also contributes to the broader field of nanotechnology applications in environmental engineering, demonstrating how advanced materials can be adapted to address pressing public health challenges.
The achievement marks another milestone for Busitema University, showcasing its growing capacity to produce high-impact research in engineering, water resources, and sustainable development. Dr. Wangi’s research not only addresses a technical challenge but also has profound implications for public health, environmental sustainability, and community resilience.
Looking forward, Dr. Wangi envisions further development and scaling of the technology.
