Microporous carbon with highly dispersed nano-lanthanum oxide (La2O3) for enhanced adsorption of methylene blue

Activated carbon doped with Lanthanum compounds are prepared and used as a preferred material for adsorption treatment systems. In this study, use of nano La2O3 and La3+ is attempted as tuning agents for granular activated carbons (GAC) and products are marked as GACLaX and GACLaOX series, produced under controlled activation (473-1273 K) for a Lanthanum/carbon ratio 0.04. They were tested for their physico-chemical features, textural superiority, and efficiency determined by XRD, FTIR, SEM, XPS, Raman, and N2/ BET and t-plots. It is found that carbon GACLaO873 (GAC activated with nano lanthanum oxide at 873 K) has good microporosity and adsorption efficiency. Nano La2O3 and La3+ incorporated extra microporosity (SAmicro) measured as 707 m(2)/g for GACLaO873 compared to native carbon GAC (589 m(2)/g). The respective surface area (SABET) of these new carbons are determined as 946 m(2)/g (GACLaO873), 953 m(2)/g (GACLa1073), and 997 m(2)/g (GAC383). Suitability of the new carbon materials in solid-liquid batch reactor systems is studied for methylene blue (MB) in concentration ranges 25-1500 mg/L. Analysis of equilibrium isotherm uptake data by John-Sivanandan Achari isotherm model found distinct features of different adsorption phases (kinks) in their plots. For GACLaO873, monolayer coverage qm(J-SA) has been 256 mg/g against the basic carbon GAC383 (190 mg/ g). Lanthanum activated carbon GACLa1073 has been noted with adsorption efficiency for metal ions, Mn (99.3%), Fe (99.1%), Co (96.6%), As (76.3%), Ba (63.0%), Li (50.4%), Al (71.3%), Cr (47.7%), Ni (99.2%), Cu (7.11%), Zn (24.3%), Cd (55.1%), Tl (32.6%) and Pd (94.9%) tested for a contaminated groundwater sample as a field trial. Lanthanum, La3+, and nano La2O3 doped activated carbon series (GACLaX and GACLaOX) prepared under a controlled condition and activation temperature X, bears good microporosity and adsorption efficiency for organic and metal ion contaminants.