Catalytic Ozonation of Acid Red 88 from Aqueous Solutions
- PDF / 372,783 Bytes
- 8 Pages / 595.276 x 790.866 pts Page_size
- 89 Downloads / 247 Views
Catalytic Ozonation of Acid Red 88 from Aqueous Solutions Sorin Marius Avramescu Æ Nicoleta Mihalache Æ Corina Bradu Æ Marian Neata Æ Ion Udrea
Received: 2 July 2008 / Accepted: 2 December 2008 / Published online: 23 December 2008 Springer Science+Business Media, LLC 2008
Abstract Degradation of Acid Red 88 (AR 88) azo dye in water was investigated in laboratory-scale experiments in presence of three metal oxide supported catalyst. Oxidation process was monitorized in terms of colour, chemical oxygen demand (COD) and total organic carbon (TOC) removals. Influence of catalysts type and aqueous solution pH were studied. Keywords Catalytic ozonation Acid Red 88 Advanced oxidation processes Mean oxidation number of carbon
1 Introduction Azo dyes are used extensively in the textile industry, photographic industry, coating industry and photochemical applications [1]. Disperse azo dyes like Acid Red 88 (AR 88) induce a significant threat to human health and ecological systems due to their widespread use, carcinogenic characteristic of degradation byproducts (such as toxic aromatic amines) and low biodegradability. Different treatment methods are currently used for dyes removal from waste effluents such us coagulation, adsorption on activated carbon, reverse osmosis and ultra filtration, etc. but these processes assure only the transfer from liquid media to a solid one and lead to formation of solid waste. Chemical oxidation is more efficient but has to be
S. M. Avramescu (&) N. Mihalache C. Bradu M. Neata I. Udrea Faculty of Chemistry, Organic Chemistry Department, University of Bucharest, Bd. Regina Elisabeta 4-12, Sector 3, Bucharest, Romania e-mail: [email protected]
optimized in order to accomplish a high removal rate along with low energy consumption. In this respect, in recent years, ozonation is emerging as a potential process for removal of dyes from water, since the chromophore groups with conjugated double bonds, can be broken down by ozone directly or indirectly forming smaller molecules and decreasing the color of the effluents [2–4]. According to some authors [5–8] ozonation process can be significantly improved by use of different catalysts. It has been emphasized that catalytic ozonation comparing with single ozonation allow the oxidation of recalcitrant compounds and lead to a considerable chemical oxygen demand (COD) and total organic carbon (TOC) reduction. This study deals with the comparative investigation of AR 88 ozonation from aqueous solutions in presence and absence of MeO/Al2O3 (Me = Ni, Cu, Co). Experiments were conducted to investigate the effects of catalyst type and solution pH which is assessed in term of decolourization, TOC removal, and COD removal.
2 Experimental 2.1 Catalytic Systems The studied catalysts (Table 1) were prepared by impregnating c-Al2O3 with nickel, copper or cobalt nitrate aqueous solutions so that the metal content on the catalyst attain 10%. Metal content in prepared solids was controlled using an atomic absorption spectrophotometer (Solar
Data Loading...
