Experimental and modeling study of water defluoridation using waste granular brick in a continuous up-flow fixed bed

Abstract

Contamination of surface and groundwater with excessive concentrations of fluoride is of significant health hazard. Adsorption of fluoride onto waste materials of no economic value could be a potential approach for the treatment of fluoride-bearing water. This experimental and modeling study was devoted to investigate for the first the fluoride removal using unmodified waste granular brick (WGB) in a fixed bed running in continuous mode. Characterization of WGB was carried out by FT-IR, SEM, and EDX analysis. The batch mode experiments showed that they were affected by several parameters including contact time, initial pH, and sorbent dosage. The best values of these parameters that provided maximum removal percent (82%) with the initial concentration of F-1 ions (10 mg/L) and agitation speed (200 rpm) were 90 min, 8, and 3 g/100 mL, respectively. The experimental data were found to fit the Freundlich isotherm model. The maximum adsorption capacity of fluoride on WGB was 1.1 mg/g. The continuous mode experiments clearly confirmed the important role of WGB bed in hindering and confining the propagation of the fluoride-loaded plume as well as there was a very good matching (RMSE ≤ 0.0398) with the predicted results obtained by the simulated mathematical model using COMSOL Multiphysics 3.5a software.

Isothermal, Kinetic, and Thermodynamic Studies on the Adsorption of Molybdenum by a Nanostructured Magnetic Material

“…The proposed methods for removing molybdate (molybdate includes Mo(VI) ion) from aqueous solutions have been described with various adsorbents, namely carbon cloths (6,7) , aluminum oxides (8), pyrite (9,10), natrolite (11), goethite (9), and iron oxide gel (12). Nanomaterials are kinds of materials that have a particle size of 100 nm or less with particular specifications (13). Many researchers have reported the application of different nanosized adsorbents such as nanoparticles (NPs) and nanotubes (14).…”