Photo-Fenton degradation of phenol, 2,4-dichlorophenoxyacetic acid and 2,4-dichlorophenol mixture in saline solution using a falling-film solar reactor

In this work, a saline aqueous solution of phenol, 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4-dichlorophenol (2,4-DCP) was treated by the photo-Fenton process in a falling-film solar reactor. the influence of the parameters such as initial pH (5-7), initial concentration of Fe2+ (1-2.5 mM) and rate of H2O2 addition (1.87-3.74 mmol min(-1)) was investigated. the efficiency of photodegradation was determined from the removal of dissolved organic carbon (DOC), described by the species degradation of phenol, 2,4-D and 2,4-DCP. Response surface methodology was employed to assess the effects of the variables investigated, i.e. [Fe2+], [H2O2] and pH, in the photo-Fenton process with solar irradiation. the results reveal that the variables' initial concentration of Fe2+ and H2O2 presents predominant effect on pollutants' degradation in terms of DOC removal, while pH showed no influence. Under the most adequate experimental conditions, about 85% DOC removal was obtained in 180 min by using a reaction system employed here, and total removal of phenol, 2,4- and 2,4-DCP mixture in about 30 min.ANP (Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)INCT-EMA (Institutos Nacionais de Ciencia e Tecnologia de Estudos do Meio Ambiente)Natl Inst Ind Property, BR-20090910 Rio de Janeiro, BrazilUniv São Paulo, Dept Chem Engn, BR-05508900 São Paulo, BrazilUniv Fed Santa Maria, Dept Chem Engn, BR-97105900 Santa Maria, RS, BrazilUniversidade Federal de São Paulo, Dept Chem Engn, BR-09972270 São Paulo, BrazilUniv Fed Rio Grande do Norte, Dept Chem Engn, BR-59066800 Natal, RN, BrazilUniversidade Federal de São Paulo, Dept Chem Engn, BR-09972270 São Paulo, BrazilWeb of Scienc