Biosorption characteristics of phosphates from aqueous solution onto Phoenix dactylifera L. date palm fibers

Phosphates are very important basic materials in agricultural and other industrial applications. The removal of phosphates from surface waters is generally necessary to avoid problems, such as eutrophication, particularly near urban areas. This paper is focused on the sorption of PO43- ions from aqueous solution onto date palm fibers as a raw, natural and abundantly materials. A series of batch tests were conducted and the influence of contact time, initial phosphate concentration, pH of the solution and adsorbent dosage on PO43- specie removal was investigated. FT-IR spectroscopy, scanning electron microscopy (SEM)/energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM) analysis of the date palm fibers before and after phosphates biosorption and desorption studies were investigated to confirm the mechanism of the retention of phosphates. Results indicate that PO43- uptake increased with increased initial phosphate concentration and decreased with increased pH values. The results showed that the highest phosphates adsorption capacity (4.35 mg/g) was found at pH 6.8, for an adsorbent dosage of 6 g/L, initial phosphate concentration of 50 mg/L, under a constant temperature of 18 degrees C +/- 02, and the equilibrium state was reached within 120 min of exposure time. The relatively low cost and high capabilities of date palm fibers make them potentially attractive adsorbents for the removal of phosphate from aqueous solution. (C) 2009 Elsevier B.V. All rights reserved