The exess of fluoride in water intended for human consoption can cause some problems in health of consumers from concentrations over than 1.5mg/L. A detailed stydu has been carried out for the removal of fluoride from concentrated rejected water overcoming the drawback of membrane processes by usiong sorption techniques. Opoka ston which is a natural sorbent and backwash residual with iron hydroxide content have been chosen and valorized in this present work as fluoride sorbents for rejected water by membranes of the water teatment plant. these sorbents have been selected in order to reduce the treatment cost and to meet the standards of rejected water especially in term of fluoride. Opoka stone and backwash residual have shown effective results for fluoride removal from rejected water with efficiency over than 77%. In order to understand the sorption phenomenon and to validate the results with sorbents, we have applied experimental data on Freudlich Isotherm and Langmuir Isotherm.

DOI: https://doi.org/10.3846/enviro.2017.071