Application of the Doehlert design for the defluoridation of industrial wastewater by adsorption onto natural clay

• Published in: Desalination and water treatment Vol. 264; pp. 141 - 150
• Main Authors: Ba, Mohamedou, Ezzeddine, Abdessalem, Dorozhkin, Sergey V., Hidouri, Mustapha
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01-07-2022
• Subjects: Adsorption; Defluoridation; Doehlert design; Industrial wastewater; Natural clay; Industrial wastewater; Defluoridation; Doehlert design; Adsorption; Natural clay
• ISSN: 1944-3986; 1944-3986
• DOI: 10.5004/dwt.2022.28570

Following the increased demand for water in addition to water resources’ strain, treatments of polluted water allow its reutilization after getting rid of all the impurities. In this work, the defluoridation of industrial wastewater by adsorption on natural clay by applying the Doehlert design was investigated. The optimized factors were the mass of clay chosen in the range 2–6 g, the concentration of fluoride ions which varies from 2,000 to 4,000 mg L–1, the pH of the medium opted in the range 2–9 and the contact time is taken varying between 20 and 40 min. The experimental response was fluoride levels in used water were considerably reduced. The elsewhere cited factors influenced the performance of the wastewater defluoridation and the quality of the rejected water after application of the Doehlert design. Herein, it is possible to determine the optimum conditions for the treatment of industrial water discharge by natural clay. The application of these conditions on a sample of industrial wastewater discharge treated with this clay gave rise to a remarkable defluoridation rate of around 99.6% which corresponded to a fluoride concentration value reduced from 4,320 mg L–1 contained in the wastewater to the standard value of 11.2 mg L–1 contained in the treated one.