Layered double hydroxides for remediation of industrial wastewater containing manganese and fluoride. (10th January 2018)

• Record Type: Journal Article
• Authors: Teixeira, Mariana A.; Mageste, Aparecida B.; Dias, Anderson; Virtuoso, Luciano S.; Siqueira, Kisla P.F.
• Is Part Of: Journal of cleaner production. Volume 171(2018)
• Page Start: 275
• Page End: 284
• Publication Date: 2018-01-10
• Subjects: Wastewater -- Manganese -- Fluoride -- Pollutants removal -- Layered double hydroxides; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2017.10.010
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: This work describes an environmentally-friendly procedure for the removal of manganese and fluoride from industrial wastewaters (IW) using layered double hydroxides (LDHs) and calcined layered double oxides (LDOs). Ternary Mg-Mn-Al LDHs (LDH-IW) were produced from IW containing a high concentration of manganese, which decreased from (99.420 ± 3.110) mg L −1 to (0.003 ± 0.001) mg L −1 after the synthesis procedure. Synthetic Mg-Al LDH was also produced for comparison purposes. Both materials were calcined and the resulting oxides (LDO and LDO-IW) were used for the removal of fluoride present in the same IW. The materials were characterized by X-ray diffraction, electron energy-loss spectroscopy, thermal analysis, Raman spectroscopy, and electron microscopy. The kinetics and adsorption isotherms for fluoride removal from aqueous solutions were studied in batch mode. For both LDO and LDO-IW, the adsorption of fluoride followed pseudo-second order reaction kinetics. Langmuir-type adsorption was observed for LDO, while adsorption by LDO-IW was according to the Freundlich model. The results showed that the oxides were able to remove 94% of the fluoride present in the IW at an initial concentration of 162 mg L −1 . The procedure reduced the concentrations of the pollutants (manganese and fluoride) to levels that complied with Brazilian effluent standards. Graphical abstract: Schematic representation of the environmentally-friendly process developed to remove manganese and fluoride pollutants from industrial wastewater. Highlights: An environmentally-friendly process for remediation of industrial wastewater. Ternary Mg-Mn-Al LDH were produced from industrial wastewater. Oxides derived from layered double hydroxides were used for fluoride removal. The process was able to suit manganese and fluoride Brazilian effluent standard. Large-scale usability and low cost are advantages of the process.