Color Reduction Of Black Liquor From Cotton Cellulose Industry Using Ozonation In An Alkaline Medium [ozonização Em Meio Básico Para Redução De Cor Do Licor Negro De Indústria De Celulose De Algodão]

Pulp and paper mills discharge large amounts of wastewater containing high concentrations of lignin, a coloring substance that is dangerous and presents high toxicity to the environment. In this study, ozonation in alkaline ambience was evaluated for color reduction in black liquor, generated in a cotton linter mill. It was observed that the ozonation time to reach 80% color reduction was higher at a lower initial ozone dose (0,4 gO3 L-1 h-1) in comparison to a higher initial ozone dose (4,3 gO3 L-1 h-1). On the other hand, the amount of consumed oxidant was lower at the lower ozone dose. It is suggested that molecular oxygen participates in the oxidation mechanism of colored compounds, which is initiated by hydroxyl radicals (•OH) formed during ozonation in alkaline ambience.1519398(2005) Standard Methods For the Examination of Water and Wastewater, , APHA/AWWA/WEF, 21th ed. American Public Health Association: Washington, DCBajpai, P., Mehna, A., Bajpai, P.K., Decolorization of kraft bleach plant effluent with the white-rot fungus trametes versicolor (1993) Process Biochemistry, 28 (6), pp. 377-384Beltran, F.J., Gonzalez, M., Gonzalez, J.F., Industrial wastewater advanced oxidation. part-i: Uv radiation in presence and absence of hydrogen peroxide (1997) Water Research, 31 (10), pp. 2405-2414Bertazzoli, R., Pelegrini, R., Descoloração e degradação de poluentes orgânicos em soluções aquosas através do processo fotoeletroquímico (2002) Química Nova, 25 (3), pp. 477-482Bijan, L., Mohseni, M., Using ozone to reduce recalcitrant compounds and to enhance biodegradability of pulp and paper effluents (2004) Water Science and Technology, 50 (3), pp. 173-182Kreetachat, T., Effects of ozonation process on lignin-derived compounds in pulp and paper mill effluents (2007) Journal of Hazardous Materials, 142 (1-2), pp. 250-257Ksibi, M., Photodegradation of lignin from black liquor using a UV/ TiO2 system (2003) Journal of Photochemistry & Photobiology A: Chemistry, 154 (2-3), pp. 211-218Langlais, B., Reckhow, D.A., Brink, D.R., (1991) Ozone In Water Treatment: Application and Engineering, , Chelsea: AWWA Research Foundation, Lewis PublishersLevenspiel, O., (2000) Engenharia Das Reações Químicas, , São Paulo, Editora Edgard Blücher LtdaMànsson, P., Oster, R., Ozonization of kraft lignin (1988) Nordic Pulp and Paper Research Journal, 3 (2), pp. 75-81Mantzavinos, D., Psillakis, E., Enhancement of biodegradability of industrial wastewaters by chemical oxidation pre-treatment (2004) Journal of Chemical Technology and Biotechnology, 79 (5), pp. 431-454Medeiros, D.R., Pires, E.C., Mohseni, M., Ozone oxidation of pulp and paper wastewater and its impact on molecular weight distribution of organic matter (2008) Ozone Science & Engineering, 30 (1), pp. 105-110Medeiros, D.R., Pires, E.C., Mohseni, M., Ozonização do efluente de extração alcalina e seu impacto sobre a biodegradabilidade e distribuição do peso molecular dos compostos orgânicos (2008) O Papel, 3, pp. 49-59Nakamura, Y., Daidai, M., Kobayashi, F., Ozonolysis mechanism of lignin model compounds and microbial treatment of organic acids produced (2004) Water Science and Technology, 50 (3), pp. 167-172Pan, X.M., Schuchmann, M.N., von Sonntag, C., Oxidation of benzene by the OH radical. A product and pulse radiolysis study in oxygenated aqueous solution (1993) Journal of The Chemical Society, 2 (3), pp. 289-297. , Perkin TransactionsSaroj, D.P., Mineralization of Some Natural Refractory Organic Compounds by Biodegradation and Ozonation (2005) Water Research, 39 (9), pp. 1921-1933Torrades, F., Experimental design of fenton and photo-fenton reactions for the treatment of cellulose bleaching effluents (2003) Chemosphere, 53 (10), pp. 1211-1220von Guntenu, U., Ozonation of drinking water: Part I. Oxidation kinetics and product formation (2003) Water Research, 37 (7), pp. 1443-1467Zaied, M., Bellakhal, N., Electrocoagulation treatment of black liquor from paper industry (2009) Journal of Hazardous Materials, 163 (2-3), pp. 995-100