ZnCl2-activated carbon was prepared using coffee husk for phosphate adsorption in aqueous solutions. Textural, morphological and structural analyses were carried out to characterize the produced materials. XRD detected the presence of ZnO in the activated carbon structure, and the measured nitrogen isotherm showed a micro-macroporous structure with 989 m2/g of specific surface area for this material. Phosphate equilibrium and kinetic experiments were conducted. Equilibrium data fit best to the Dubinin-Radushkevich model (r2≥0.96), with maximum adsorption capacities of 59.38 – 63.87 mg P/g in the pH range between 5 and 9. Intraparticle diffusion was the rate-limiting mechanism of the adsorption.

Composite material (AC-ZnO) was prepared by growing ZnO nanoparticles during the production of biomass based-activated carbon (AC) via the incorporation of zinc acetate in the process. Comprehensive analyses confirmed the presence of ZnO nanoparticles over the AC surface and described the particular nature of the composite adsorbent. Methylene blue (MB) equilibrium data fitted the Dubinin-Radushkevich model. The MB adsorption capacity was higher for the bare activated carbons (197.9–188.7 mg/g) than the activated carbons with ZnO nanoparticles (137.6–149.7 mg/g). The adsorption of the MB on the adsorbents is physical because the mean adsorption energy (E) is between 1.76 and 2.00 kJ/mol. Experiments that combine adsorption and photocatalysis were carried out with different loads of adsorbents and with and without UV-light exposure. Photocatalytic activity was identified mostly at the...

An activated carbon (adsorbent) was prepared from a forestry residual biomass (Capparis scabrida sawdust) by chemical activation with ZnCl2. The adsorbent was tested in kinetic experiments to remove three anionic dyes widely used in the food industry: tartrazine (TR), brilliant scarlet 4R (BS4R) and brilliant blue (BB). The adsorbent was able to remove the dyes in different intensities, and the revealed order of their adsorption ability was BS4R>TR>BB. Most of the kinetic data fit best to the pseudo-second order model; however, high accordance with other models indicates that there is more than one phenomenon to explain the adsorption process. Analyzing the data that fit well to the pseudo-second order model and considering that the equilibrium was reached, the equilibrium adsorption capacity (qe) for TR was 55.3 mg/g (when the AC load was 1 g/l and the TR initial concentration was 50 mg...

Se produjo biocarbón a partir de residuos de coronta de maíz (Zea mays) para remover plomo de soluciones acuosas. La carbonización del residuo se realizó a 600 °C por 2 h a 1 atmosfera de nitrógeno controlada. Se realizaron análisis texturales, morfológicos y estructurales para caracterizar el material. De los datos de la isoterma de adsorción de N2, el material mostró una estructura microporosa de 144,13 m2/g de área superficial. Se realizaron experimentos de adsorción de Pb2+ en equilibrio y cinética, donde los datos de equilibrio se ajustan mejor al modelo de Dubinin-Radushkevich (R2 ≥ 0,990) con capacidad de adsorción máxima de 12,16 mg/g con. Asimismo, para los datos de cinética, el modelo con mejor ajuste fue el de Elovich (R2 ≥ 0,994). Sin embargo, la cinética de adsorción también se ajustó a los modelos de Pseudo-Primer orden (R2 ≥ 0,990) y Pseudo- Segun...

Se produjo biocarbón a partir de residuos de coronta de maíz (Zea mays) para remover plomo de soluciones acuosas. La carbonización del residuo se realizó a 600 °C por 2 h a 1 atmosfera de nitrógeno controlada. Se realizaron análisis texturales, morfológicos y estructurales para caracterizar el material. De los datos de la isoterma de adsorción de N2, el material mostró una estructura microporosa de 144,13 m2/g de área superficial. Se realizaron experimentos de adsorción de Pb2+ en equilibrio y cinética, donde los datos de equilibrio se ajustan mejor al modelo de Dubinin-Radushkevich (R2 ≥ 0,990) con capacidad de adsorción máxima de 12,16 mg/g con. Asimismo, para los datos de cinética, el modelo con mejor ajuste fue el de Elovich (R2 ≥ 0,994). Sin embargo, la cinética de adsorción también se ajustó a los modelos de Pseudo-Primer orden (R2 ≥ 0,990) y Pseudo- Segun...