Issabayeva, G. and Wong, S.H. and Pang, C.Y. and Wong, M.C. and Aroua, M.K. (2022) Fluoride removal by low-cost palm shell activated carbon modified with prawn shell chitosan adsorbents. International Journal of Environmental Science and Technology, 19 (6). pp. 3731-3740. ISSN 1735-1472
Full text not available from this repository.Abstract
Hydrofluoric acid is used in large volumes during solar panels manufacturing for cleaning purpose. It results in the generation of wastewater containing high concentrations of fluoride. Chemical precipitation is commonly used to remove most of fluoride from the wastewater. It reduces fluoride concentration to ~ 20 mg/L, whereas the discharge standard is set to 2 mg/L. Adsorption is preferable when dealing with diluted wastewater. This study evaluated the adsorption of fluoride using two low-cost adsorbents: granular palm shell activated carbon and its modification with the prepared chitosan of prawn shells. The effects of pH, dosage, contact time and initial fluoride concentration were studied in batch mode adsorption experiments. The highest removal efficiencies of fluoride by two adsorbents comprised 46% and 55%, respectively, at pH 2 and pH 7. The contrasting behavior of the two adsorbents in relation to pH is attributed by the adsorbents surface charge associated with the surface functional groups identified by FTIR. The adsorption isotherm modeling showed better fit to the Langmuir model for both adsorbents. Adsorption kinetics results fitted well into the pseudo-second-order kinetics model suggesting chemisorption mechanism of fluoride removal.