Sustainable and Cost-Effective Defluoridation of Rural Tanzanian Groundwater through Pyrolyzed-Eggshells Packed into Parallel Adsorbent Columns

Abstract

Record ID: 319

Award(s): Excellence in Undergraduate Research Mentorship; Excellence in Research Communication

Program Affiliation: Capstone

Presentation Type: Podium

Abstract:  community of Burere, Tanzania. Current fluoride levels in the community is approximately 5 times above the World Health Organization's recommendations. Excessive exposure to fluoride poses health and quality challenges to the community. Significant design constraints are imposed on this project including cost, material supply, technical labor, and equipment sourcing. The system had to handle substantial water flow rate, low capital costs, and deliver minimal ongoing cost to the community. This study began with the investigation of 10 water treatment methods, each of which were extensively researched for feasibility and viability. Amongst the process choices, pyrolyzed-eggshells utilized as an adsorbent filtrate emerged as the most favorable process. Engineering considerations and calculations were refined to provide a more comprehensive evaluation of the process design. The system comprises 12 filter columns arranged in parallel receiving water from an elevated tank to allow flow via gravity. The initial project investment was furnished by Engineering without Borders, with ongoing operational costs supported by the village in Burere. The anticipated capital outlay for the current design shows economic promise, estimated at around $5,000. Annual operating cost was minimized in this design due to the availability of eggshell material which is currently local waste. After confirmation of design upon further scale up and laboratory testing, the aspirational outcome of this study is the construction of the finalized design.