Naslov
Advanced oxidation of an azo dye C.I. Acid Orange 7, 2-Naphtol and Sulphanilic acid in aqueous solution: effect of Fenton treatment on mineralization, toxicity and biodegradability

Autori
Peternel, Igor ; Papic, Sanja ; Koprivanac, Natalija ; Kusic, Hrvoje ; Krevzelj, Zeljko

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
The 17th International Conference on Advanced Oxidation Technologies for Treatment of Water / Hussain Al-Ekabi - London : Ontario : Redox Technologies, 2011

Skup
The 17th International Conference on Advanced Oxidation Technologies for Treatment of Water, Air and Soil

Mjesto i datum
San Diego (CA), Sjedinjene Američke Države, 07.09.2011. - 10.09.2011

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
advanced oxidation processes; organic dye; Fenton process

Sažetak
From the start of the synthetic dye industry in 1865. until nowdays several millions of different colored chemical compounds have been synthesized and about 10 000 of these were or are produced on an industrial scale. Azo dyes, characterized by the presence of one or more azo groups (-N=N-) bound to aromatic rings, are the largest and most important class of synthetic dyes. It has been estimated that more than 50 % of all dyes in common use are azo dyes because of their chemical stability and versality. Dyes are widely used in textile, paper, leather, pharmaceutical, cosmetics and food industries. They are also used in high-tech applications, such as in the medical, electronics, and especially the nonimpact printing industries. important textile fibers are cotton, the largest, and polyester. Consequently, dye manufacturers tend to concentrate their efforts on producing dyes for these two fibers. The world production of dyes in 1990 was 1106 t. The production of high-tech dyes will remain small in comparison to dyes for traditional applications especially textile dyeing. Thus, the treatment of such effluents is important for the protection of natural waters and environment. In this study, C.I. Acid Orange 7 azo dye (AO7) and intermediates for its production, sulphanilic acid (SA) and 2-naphthol (2-NAP) were chosen as model pollutants. Special attention has been paid on the oxidative degradation of AO7, a representative monoazo textile dye, by means of various APOs including Fenton treatment. AO7 can be partially biodegraded by anaerobic treatment to give, by the reduction of azo bond, the primary products sulphanilic acid (SA) and 1-amino-2-naphthol (AN). These products can be very harmful for the ecosystems and human health. Sulphanilic acid, SA, (4-aminobenzensulphonic acid) is a typical representative of aromatic sulphonated amines. Biodegradation of SA is difficult, as the sulpho group is a xenobiotic structural element, and the strongly charged anionic moiety prevents penetration of the compound through bacterial membranes. Phenols have been listed as priority pollutants by US Environmental Protection Agency and European Union. Naphthalene derivatives with substituents at position 2 are usually more toxic than those at position 1. Because of strong toxicity and low biodegradability, the removal of 2-naphthol (2-NAP) is of great importance in water treatment or soil remediation. Considering the above mentioned facts, the objective of the present work was to study the degradation of AO7 and intermediates for its synthesis SA and 2-NAP in aqueous solutions by Fenton advanced oxidation process. Factorial plan (two factors, concentrations of catalyst Fe2+ and oxidant H2O2, on three levels of values) in combination with response surface methodologies (RSM) was used for process optimization relating to TOC removal. The effectiveness evaluation of applied treatment process for all three pollutants was conducted on the basis of reduced initial A485 (color), A254 (aromatic content) , TOC (total organic carbon), COD (chemical oxygen demand), BOD (biochemical oxygen demand) and EC50 (toxicity to the bioluminescent bacteria Vibrio fischeri) +. The conclusions about possibility of combining Fenton process with biological treatment are also presented.

Izvorni jezik
Engleski

Znanstvena područja
Kemijsko inženjerstvo

POVEZANOST RADA