title: Solar photocatalytic degradation of textile effluent with TiO2, ZnO, and Nb2O5catalysts: assessment of photocatalytic activity and mineralization.
abstract: The photocatalytic degradation of textile effluent was investigated using TiO2, ZnO, and Nb2O5catalysts under solar irradiation. The procedures were carried out at ambient conditions in April 2014, with pH 3.0 and catalyst concentration of 0.250 g L-1. The photocatalytic activity of the oxides was evaluated by means of kinetic efficiency (rate constant and half-life time), chemical oxygen demand reduction, and absorbance reduction at 228, 254, 284, 310, 350, 500, and 660 nm (λmáx). Mineralization in terms of the formation of inorganic ions and toxicity reduction using bioassays with Artemia salina were performed. TiO2reduced the absorbance at 660 nm (λmax) after 300 min of solar irradiation around 94 and 93%; and 68 and 60% of COD, respectively. ZnO showed lower photocatalytic activity giving 64 and 42% of absorbance and COD reduction, respectively. The photocatalytic activity of Nb2O5was very close to TiO2-P25. In this sense, Nb2O5becomes a promising alternative to replace the commercial TiO2-P25. Bioassays confirmed the efficacy of treatment, increasing the lethal concentration of 27.59 (in natura) to 131.95% in the presence of Nb2O5.
authors.affiliation: Department of Chemistry, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá, PR, 87020-900, Brazil.|Department of Bioprocess Engineering and Biotechnology, Universidade Tecnológica Federal do Paraná, Estrada para Boa Esperança Km 04, Dois Vizinhos, PR, 85660-000, Brazil.
authors.forename: Renata P
authors.initials: RP
authors.lastname: Souza
authors.affiliation: Department of Chemistry, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá, PR, 87020-900, Brazil.
authors.forename: Elizangela
authors.initials: E
authors.lastname: Ambrosio
authors.affiliation: Department of Chemistry, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá, PR, 87020-900, Brazil.
authors.forename: Maisa T F
authors.initials: MTF
authors.lastname: Souza
authors.affiliation: Department of Chemistry, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá, PR, 87020-900, Brazil.
authors.forename: Thábata K F S
authors.initials: TKFS
authors.lastname: Freitas
authors.affiliation: Department of Technology in Chemical Processes, Universidade Tecnológica Federal do Paraná, Rua Marcílio Dias 635, Apucarana, PR, 86812-460, Brazil. ana_eq@hotmail.com.
authors.forename: Ana M
authors.initials: AM
authors.lastname: Ferrari-Lima
authors.affiliation: Department of Chemistry, Universidade Estadual de Maringá, Avenida Colombo 5790, Maringá, PR, 87020-900, Brazil.
authors.forename: Juliana C
authors.initials: JC
authors.lastname: Garcia
mesh_terms: D002384:Catalysis; D009556:Niobium; D010087:Oxides; D013784:Textiles; D014025:Titanium / Q000528:radiation effects*; D014874:Water Pollutants, Chemical / Q000528:radiation effects*
chemical_list: D010087:Oxides; D014874:Water Pollutants, Chemical; D009556:Niobium; C009495:titanium dioxide; D014025:Titanium; C073337:niobium pentoxide
keywords: Ecotoxicity; Mineralization; Solar irradiation; Solar photodegradation; Textile effluent