GEOCHEMICAL AND MINERALOGICAL CHARACTERIZATION OF SOME CLAY MATERIALS AS FLUORIDE ADSORBENT FROM GROUNDWATER IN GHANA

Abstract

This research conducted in the Upper East Region of Ghana characterizes Termitaria and residual clays from Navrongo to establish effective fluoride adsorbent from boreholes in Bongo area. Specific objectives are to determine (1) geochemical and mineralogical compositions of the clays using ICP-MS and X-ray diffraction devices, respectively; (2) fluoride degradation in groundwater using a Batch test (3) water quality after fluoride removal. The Batch test uses 250 ml of groundwater with 2.29 mg/l fluoride and clay masses of 25, 50, 100 and 200 grams to perform within a minimum and varying time of 10 minutes to a maximum of 120 minutes. Results indicate enrichments of major elements in Termitaria clay and trace elements in residual clay. Fluoride reduces to 0.778 mg/l and 0.294 mg/l at a mass of 0.8 kg/l over 80 minutes for Termitaria and residual clays, respectively. Optimum defluoridation time occurs within an hour in the pH range of 7.83 to 8.04. Quartz-hematite-magnetite-illite-montmorillonite suite occurs in residual clay with defluoridation capacity of 66.25 %, while quartz-illite-montmorillonite suite occurs in Termitaria clay with defluoridation capacity of 87.25 %, and constitute the more efficient adsorbent. TDS and conductivity are within WHO standard guidelines, which confirms the clays as non-toxic.

Keywords

• concentration
• fluoridation
• termitaria
• residual
• navrongo
• bongo.