Composites of ZnO nanoparticles and biomass based activated carbon: adsorption, photocatalytic and antibacterial capacities

• Published in: Water science and technology Vol. 2017; no. 2; pp. 492 - 508
• Main Authors: Cruz, G J F, Gómez, M M, Solis, J L, Rimaycuna, J, Solis, R L, Cruz, J F, Rathnayake, B, Keiski, R L
• Format: Journal Article
• Language: English
• Published: England IWA Publishing 01-05-2018
• Subjects: Acetates; Acetic acid; Activated carbon; Adsorbents; Adsorption; Anti-Bacterial Agents - pharmacology; Antibacterial materials; Aquatic ecosystems; Bacteria; Biomass; Capacity; Carbon; Catalytic activity; Catalytic oxidation; Cations; Charcoal - analysis; Composite materials; Developing countries; Dyes; E coli; Equilibrium; Escherichia coli - drug effects; Experiments; Heavy metals; Iron; LDCs; Loads (forces); Metal Nanoparticles - analysis; Methylene blue; Nanoparticles; Nitrogen; Photocatalysis; Photolysis; Raw materials; River water; Rivers; Salmonella; Salmonella typhimurium - drug effects; Seeds; Spondias; Ultraviolet radiation; Waste Disposal, Fluid - methods; Water Pollutants, Chemical - chemistry; Water pollution; Water treatment; Zinc; Zinc acetate; Zinc oxide; Zinc Oxide - analysis
• DOI: 10.2166/wst.2018.176
• EISSN: 1996-9732
• ISSN: 0273-1223

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 first stage of the adsorption process and, in the case of experiments with less load of the composite AC-ZnO, because the light obstruction effect of the activated carbon is more for higher loads. The ZnO grown over AC improves the adsorption of cations such as Pb, Al and Fe in aqueous phase (polluted river water) and provides antibacterial capacity against Escherichia coli and Salmonella typhimurium.