Papers by Evalde Mulindankaka
Science of The Total Environment, 2014
Both surface and intra-particle diffusion were rate-controlling processes. • Soil composition inf... more Both surface and intra-particle diffusion were rate-controlling processes. • Soil composition influences the partition activity of NP. • Soil organic matter has dominated the sorption capacity of NP on soil. • NP molecule was limited to migrate to deep soil in sewage-irrigated area.
Journal of Earth Science, 2016
The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides (FM) was inv... more The adsorptive removal of arsenic by synthetically-prepared nano Fe-Mn binary oxides (FM) was investigated. A novel method using potassium permanganate and ferric chloride as raw materials was used to synthesise FM. The molar ratio of Fe and Mn in the synthetic Fe-Mn binary oxides was 4 : 3. The FM-1 and FM-2 (prepared at different activation temperatures) having high specific surface areas (358.87 and 128.58 m 2 /g, respectively) were amorphous and of nano particle types. The amount of arsenic adsorbed on FM-1 was higher than that adsorbed on FM-2 particles. After adsorption by FM-1, residual arsenic concentration decreased to less than 10 μg/L. The adsorption kinetics data were analyzed using different kinetic models including pseudo first-order model, pseudo second-order model, Elovich model and intraparticle diffusion model. Pseudo second-order kinetic model was the most appropriate model to describe the adsorption kinetics. The adsorption percentage of As(III) increased in the pH range of 2-3 while it decreased with the increase of pH ( 3<pH<10). The effects of coexisting anions on As(III) removal using FM-1 and FM-2 were also studied and the order of the effects is as follows: NO 3 -, Cl -, F -<SO 4 2-, HCO 3 -<H 2 PO 4 -, indicating that H 2 PO 4 -is the major competitor with As(III) for adsorptive sites on the surface of the adsorbents. The higher adsorption capacity of FM-1 makes it potentially attractive adsorbent for the removal of As(III) from groundwater. KEY WORDS: arsenite, adsorption, nano Fe-Mn binary oxide, kinetics, pH. Arsenic contamination of groundwater has become a major challenge for the health of human society and ecosystem . High concentrations of arsenic have been found in groundwater in many countries such as Argentina,
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Papers by Evalde Mulindankaka