Destruction of the organic matter present in effluent from a cellulose and paper industry using photocatalysis

• Published in: Journal of photochemistry and photobiology. A, Chemistry. Chemistry., 2003-02, Vol.155 (1), p.231-241
• Main Authors: Machado, Antonio Eduardo H., de Miranda, Jacques A., de Freitas, Renato F., Duarte, Edward Thomas F.M., Ferreira, Lucas F., Albuquerque, Yaico D.T., Ruggiero, Reinaldo, Sattler, Christian, de Oliveira, Lamark
• Format: Article
• Language: English
• Subjects: Applied sciences; Crosslinking and degradation; Degradation; Effluent; Exact sciences and technology; General purification processes; Lignin fragments; Lignosulphonate; Photocatalysis; Physicochemistry of polymers; Pollution; Polymers and radiations; TiO 2; Wastewaters; Water treatment and pollution
• ISSN: 1010-6030; 1873-2666
• DOI: 10.1016/S1010-6030(02)00393-3

The use of photocatalysis to perform the degradation of the organic matter present in the effluent from a paper and cellulose mill was studied. The best conditions for the photocatalytical process at a laboratory scale were determined using real effluent and an aqueous solution of a pre-degraded lignosulphonate as model, for large-scale studies. The results show that the reaction is little influenced by temperature, the apparent activation energy being between 7.9 and 10.5 kJ/mol, typical of phenol degradation mediated by TiO 2. On the other hand, pH, the use of some additives, and the morphology of the photocatalyst exert a considerable influence on the results. P25 proved to be a better photocatalyst than anatase, giving a 60% higher degradation rate. The addition of hydrogen peroxide in the reactions mediated by P25 resulted in an increase of 173.5% in the efficiency of the photocatalytical process. When compared to the reaction induced by anatase, the increase in efficiency was 354%. The association of TiO 2 and a photosensitizer (zinc phthalocyanine) gave a small increase (