ACEWM’s PhD Candidate Emeru Assefa Weldetensay successfully defended his Dissertation
The Africa Center of Excellence for Water Management (ACEWM) is proud to announce that PhD candidate Emeru Assefa Weldetensay has successfully defended his doctoral dissertation, marking a significant contribution to water treatment research and public health in Ethiopia. His dissertation, titled “Enhancing Natural Organic Matter Removal and Mitigating Disinfection By-Product Formation Potential in Koka Drinking Water Treatment Plant, Ethiopia,” addresses a critical challenge in water safety—balancing disinfection effectiveness while minimizing harmful by-products.
In his research, Emeru investigated the limitations of the existing treatment process at the Koka Water Treatment Plant (WTP), focusing on the removal efficiency of natural organic matter (NOM)—a key precursor to the formation of carcinogenic disinfection by-products (DBPs) when chlorine is used during water disinfection. His study found that the current treatment methods at Koka WTP are insufficient, with seasonal variations yielding only 34% and 28% average total organic carbon (TOC) removal in the wet and dry seasons, respectively.
To address this, Emeru developed and tested novel treatment materials—Alum-Chalaltu and TiO₂-Chalaltu composites—which showed remarkable results. The Alum-Chalaltu composite achieved up to 90% dissolved organic carbon (DOC) and 91.1% UV254 absorbance removal, making it up to 7.8 times more effective than the conventional coagulation-flocculation (CF) method, while also reducing alum use by 58%. Similarly, TiO₂-Chalaltu demonstrated 91.1% TOC removal, outperforming the existing method by over 1.5 times. These materials offer a cost-effective, efficient, and scalable solution to reduce DBP risks, contributing significantly to safer drinking water and public health.
The dissertation was supervised by Dr. S. Anuradha Jabasingh (Addis Ababa University), with co-supervision from Prof. Abi Taddesse (Haramaya University), Dr. Eyobel Mulugeta (Bio and Emerging Technology Institute) and Dr. Meseret Dessalegn (The Aquaya Institute). The defense session was chaired by Prof. Feleke Zewge (Addis Ababa University), with internal and external examination conducted by Prof. Yonas Chebude (Addis Ababa University) and Prof. Dr.-Ing Esayas Alemayehu (Jimma University).
Emeru Assefa Weldetensay’s successful defense not only reflects his academic excellence but also sets a precedent for innovative, locally applicable solutions to water quality challenges. His work underscores ACEWM’s commitment to nurturing research that addresses Africa’s pressing environmental and public health needs.