Development of Kaolin Clay as a Cost-Effective Technology for Defluoridation of Groundwater

Abstract

Excessive fluoride in potable groundwater is a serious health problem in rural areas of many developing countries. The presence of a small amount of fluoride in potable water is beneficial to human health, but a high amount (>1.5 mg/L) has adverse effects. The present study is aimed to prepare a new cost-effective adsorbent of kaolin clay that can be used as a valuable defluoridating agent. Characterization of the prepared adsorbent was carried out using DSC, FTIR, TGA, and XRD. Also, the surface area of the adsorbent was measured by BET analysis. The clay was activated with concentrated H2SO4, and the effects of various experimental parameters such as temperature (25, 40, 50, and 60°C), pH (2, 4, 6, and 8), particle size (<0.075, 0.075–0.15, and 0.15–0.30 mm), contact time (30, 60, 90, 120, and 150 min), and dose of the adsorbents (0.5, 1, 1.5, 2.0, and 2.5 g) were investigated using a batch adsorption method. The specific surface area of raw and activated clay was found to be 10.598 m2/g and 5.258 m2/g, respectively. The optimum fluoride removal by both adsorbents was obtained at pH 4, temperature 50°C, particle size 0.075 mm, and 60 min. In both adsorbents, the degree of fluoride removal was increased with a decrease in the particle size of the adsorbent and increased contact time and dosage of the adsorbent. In all parameters, adsorption by activated clay was better than raw kaolin clay for retaining fluoride. The obtained data were well fitted with Freundlich and Langmuir isotherm models.

Removal of natural organic matter fractions by adsorptive asymmetric ceramic membrane functionalized with in situ phytogenic nanoscale zero valent iron: Performance and Fenton cleaning strategy

“…A weak relationship ( R 2 = 0.84) describing the intraparticle diffusion of BSA onto the adsorbent as explained by the Webber‐Morris intraparticle diffusion model was deduced. The average C value from the Webber‐Morris intra‐particle diffusion model was 0.0477 mg g −1 , indicating a relatively thin inter diffusion boundary layer between DOC and adsorbents 43 . According to Webber‐Morris model, adsorption is a culmination of three stages.…”

“…The average C value from the Webber-Morris intra-particle diffusion model was 0.0477 mg g À1 , indicating a relatively thin inter diffusion boundary layer between DOC and adsorbents. 43 According to Webber-Morris model, adsorption is a culmination of three stages. A comparison of the maximum adsorption capacity of K-nZVI for BSA with literature reporting related adsorbents shows that the adsorption capacity of K-nZVI was higher than most adsorbents (Table 6).…”

Modeling the adsorption process for fluoride removal from groundwater by machine learning

“…Defluoridation of groundwater is attained by various processes such as membrane separation, 7 chemical precipitation, 8 adsorption, 9 ion exchange, 10 nanofiltration, 11 reverse osmosis, 12 electrodialysis, 13 and electrocoagulation 14 . Ion exchange and membrane separation processes are not standard because of their high maintenance and installation cost.…”

Physiochemical Characterization of Ethiopian Mined Kaolin Clay through Beneficiation Process

“…Te association of iron with kaolin can occur in three diferent forms such as (a) hematite, goethite, and pyrite, (b) substitution in the crystal network of minerals such as anatase, rutile, and mica, and (c) as surface absorption on montmorillonite and kaolin. Kaolin is used for various applications such as pottery, efuent waste treatment [5], composite fller manufacturing [6], and solid catalyst production such as zeolite [7][8][9][10].…”