Design of Hybrid Goethite Nanocomposites As Potential Sorbents for Lanthanum from Aqueous Media

Nano-goethite (NG) was synthesized using a co-precipitation method, where the surface of NG was modified by composite formation with activated carbon and sodium alginate, respectively, to increase adsorption capacity. The adsorption process of La(III) was optimized at defined conditions: pH 5.0, contact time 6.0 h, sorbent dosage (0.1 g/20 ml) and an initial La(3+)concentration (500 ppm). The maximum La(III) adsorption capacity (mg/g) was determined using the Sips model, as follows: pristine NG (49.5), activated carbon modified goethite: GAC-2 (44.0) and GAC-1 (56.8), and sodium alginate modified goethite: GSA-1 (63.9) and GSA-2 (77.8). The kinetic uptake profiles of La3+ were described by pseudo first order model. The sorbents can be classified according to their relative adsorption capacity, as follows: GSA-2 > GSA-1 > GAC-1 > NG > GAC-2.