| Title | Biodegradability enhancement of refractory pollutants by ozonation: A laboratory investigation on an azo-dyes intermediate |
| Abstract | The effectiveness of ozone treatment for improving the biodegradability of recalcitrant pollutants has been proved by investigating the ozonation reaction of FAST-VIOLET-B (FVB) a bioresistant chemical intermediate of ate-dyes. Laboratory scale experiments have been carried out, at room temperature, by bubbling, for 90 min, ozonated air (9ppmO(3)/min) into 0.35 l of an alkaline (pB=11) aqueous solution (50 ppm) of FVB. The experimental results indicate that during the ozonation, even though complete FVB degradation occurs in 10 min, ozone consumption goes on for a further 20-min after which time most degradation reactions are completed. The main ozonation by-products, identified by HPLC, IC, and GC-MS are formaldehyde, acetaldehyde, glyoxal, acetone, acetic-, formic-, oxalic- and carbonic-acid, plus six FVB derivatives scarcely biodegradable. At the end of the ozonation, i.e. after 30 min., the initial values of TOC (35 mgC/l) and COD (103 mgO(2)/l) are respectively 27 and 25 and correspond to a relative removal of about 23% and 76%. As for FVB solution biodegradability expressed as (BOD5)/COD) ratio, during the first 10 min its value regularly increases from zero up to a maximum of 0.75 that corresponds to an ozone consumption of 2.4 mg per each mg of organic carbon initially present in the solution. (C) 1998 Published by Elsevier Science Ltd. All rights reserved. |
| Source | Water science and technology 38 (4-5), pp. 239–245 |
| Keywords | refractory pollutantsozonationbiodegradabilitychemical oxidationsintegrated processes |
| Journal | Water science and technology |
| Editor | IWA Publishing, London, |
| Year | 1998 |
| Type | Articolo in rivista |
| DOI | 10.1016/S0273-1223(98)00536-8 |
| Authors | Lopez, A; Ricco, G; Mascolo, G; Tiravanti, G; Di Pinto, AC; Passino, R |
| Text | 323823 1998 10.1016/S0273 1223 98 00536 8 ISI Web of Science WOS 000077349000031 refractory pollutants ozonation biodegradability chemical oxidations integrated processes Biodegradability enhancement of refractory pollutants by ozonation A laboratory investigation on an azo dyes intermediate Lopez, A; Ricco, G; Mascolo, G; Tiravanti, G; Di Pinto, AC; Passino, R Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque, via F. De Blasio, 5,70123 Bari, Italy; Consiglio Nazionale delle Ricerche, Istituto di Ricerca Sulle Acque, via Reno, 1,00198 Roma, Italy The effectiveness of ozone treatment for improving the biodegradability of recalcitrant pollutants has been proved by investigating the ozonation reaction of FAST VIOLET B FVB a bioresistant chemical intermediate of ate dyes. Laboratory scale experiments have been carried out, at room temperature, by bubbling, for 90 min, ozonated air 9ppmO 3 /min into 0.35 l of an alkaline pB=11 aqueous solution 50 ppm of FVB. The experimental results indicate that during the ozonation, even though complete FVB degradation occurs in 10 min, ozone consumption goes on for a further 20 min after which time most degradation reactions are completed. The main ozonation by products, identified by HPLC, IC, and GC MS are formaldehyde, acetaldehyde, glyoxal, acetone, acetic , formic , oxalic and carbonic acid, plus six FVB derivatives scarcely biodegradable. At the end of the ozonation, i.e. after 30 min., the initial values of TOC 35 mgC/l and COD 103 mgO 2 /l are respectively 27 and 25 and correspond to a relative removal of about 23% and 76%. As for FVB solution biodegradability expressed as BOD5 /COD ratio, during the first 10 min its value regularly increases from zero up to a maximum of 0.75 that corresponds to an ozone consumption of 2.4 mg per each mg of organic carbon initially present in the solution. C 1998 Published by Elsevier Science Ltd. All rights reserved. 38 Biodegradability enhancement of refractory pollutants by ozonation A laboratory investigation on an azo dyes intermediate 25.pdf Articolo in rivista IWA Publishing 0273 1223 Water science and technology Water science and technology Water science and technology. Water sci. technol. antonio.lopez LOPEZ ANTONIO giuseppe.mascolo MASCOLO GIUSEPPE |
