Study of Activated Alumina Coated Laterite for Defluoridation of Water

Undergraduate #50
Discipline: Chemistry and Chemical Sciences
Subcategory: Water

Kristen Hypolite - Southern University and A&M College
Co-Author(s): Lamar K. Burton and Kristen Hypolite, Southern University and A&M College Juliet Osei, Kwame Nkruma University of Science and Technology

Provision of potable water is a global problem. Many countries lack the technology necessary to provide such a fundamental requisite to their communities. The goal of the NSF-IRES research team is to present a sustainable solution that brings fluoride rich water to levels below 1.5mg/L, as mandated by the World Health Organization. Specifically, fluoride rich borehole water from the Bongo District in Northeastern Ghana requires a robust system for this mandate. The method of ion exchange utilizing laterite treated with a highly porous adsorbent, activated alumina (Al2O3), was examined for fluoride removal using kinetic and concentration experiments. The samples tested contained Fluoride concentrations ranging from 5 to 20 mg/L, which is typically found in the natural water systems in this area. In each of the experiments, samples were tested under the same conditions; varying pH, temperature, and concentration. Results were analyzed and fit to the Langmuir and Freundlich Isotherms and are presented in the study to demonstrate adsorption “affinity” and capacity for each sample. Kinetic studies revealed that lower concentrations resulted in the greatest Fluoride uptake when contacted with the treated laterite. A steep rise near the origin of the plot for Sample A curve is a typical indication of a strong “affinity”; a trend not so evident in the other samples. However, when determining for the needs of maximum saturation, samples with higher concentrations performed best. It is expected that samples with lower concentrations are the optimal solution for defluoridation of borehole water in the northeastern region of Ghana.

Funder Acknowledgement(s): National Science Foundation

Faculty Advisor: Patrick Mensah,