Abstract:
High concentration of fluoride (> 1.5 mg/L) in drinking water causes different health problems.
Therefore, the aim of the study was fluoride removal capacity of activated L. albus under
laboratory batch adsorption set up. The Physicochemical properties of the activated L. albus
Moisture Content (%), Ash Content (%), pH and FTIR spectra of the adsorbent before and after
adsorption were studied. The influence of parameters such as: pH of the solution, contact time,
adsorbent doses, initial fluoride concentration, and the presence of co-existing anions was
investigated. High fluoride removal efficiency (97.69%) was observed at PH 7 and equilibrium
was achieved within 30 min of agitation time. The amount of fluoride adsorbed increase with
increasing the dose of the adsorbent from 1 to 5 g/L. The equilibrium data tested with
Langmuir, Freundlich, Sips and Redlich-Peterson Isotherm at room temperature and it was
found that the Freundlich Isotherm (R2=0.9901) best fitted the adsorption of fluoride. The
equilibrium removal capacity was observed using 5 g/L of the adsorbent. The experimental
Kinetics of the data was analyzed using pseudo-first-order, pseudo-second-order and Weber Morris Intra-particle kinetics model. Kinetics data followed the non-linear pseudo-first-order
model (R2 = 0.96) for L. albus adsorbent. The adsorption capacity decrease from 68 to 56% with
the increase of bicarbonate concentration from 10 to 200 mg/L. The results obtained from this
study could provide important information for evaluating the application of L. albus for
removal of fluoride from drinking water. Therefore, the result obtained uses for further
investigation.
