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

• Published in: Environmental technology 2014-02, Vol.35 (3), p.364-371
• Main Authors: Luna, Airton J, Nascimento, Cláudio A.O, Foletto, Edson Luiz, Moraes, José E.F, Chiavone-Filho, Osvaldo
• Format: Article
• Language: English
• Subjects: 2,4-D; 2,4-dichlorophenol; 2,4-Dichlorophenoxyacetic Acid - chemistry; 2,4-Dichlorophenoxyacetic Acid - isolation & purification; 2,4-Dichlorophenoxyacetic Acid - radiation effects; Acids; Applied sciences; aqueous solutions; Chemical engineering; Complex Mixtures - chemistry; Complex Mixtures - isolation & purification; Complex Mixtures - radiation effects; dichlorophenoxyacetic acid; dissolved organic carbon; Electric Power Supplies; environmental technology; Equipment Design; Equipment Failure Analysis; Exact sciences and technology; falling-film reactor; hydrogen peroxide; Hydrogen Peroxide - chemistry; Hydrogen Peroxide - radiation effects; iron; Iron - chemistry; Iron - radiation effects; phenol; Phenols; Phenols - chemistry; Phenols - isolation & purification; Phenols - radiation effects; photo-Fenton; Photocatalysis; Photochemistry - instrumentation; Photochemistry - methods; photolysis; pollutants; Pollution; Reactors; response surface methodology; sodium chloride; Sodium Chloride - chemistry; Sodium Chloride - radiation effects; Solar Energy; solar radiation; sunlight; Water Purification - instrumentation
• ISSN: 1479-487X; 0959-3330; 1479-487X
• DOI: 10.1080/09593330.2013.828762

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 Fe ²⁺ (1–2.5 mM) and rate of H ₂O ₂ 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. [Fe ²⁺], [H ₂O ₂] and pH, in the photo-Fenton process with solar irradiation. The results reveal that the variables’ initial concentration of Fe ²⁺ and H ₂O ₂ 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.