Photocatalytic and combined anaerobic–photocatalytic treatment of textile dyes

• Published in: Chemosphere (Oxford) Vol. 72; no. 11; pp. 1816 - 1822
• Main Authors: Harrelkas, F., Paulo, A., Alves, M.M., El Khadir, L., Zahraa, O., Pons, M.N., van der Zee, F.P.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2008; Elsevier
• Subjects: Aerobiosis; Anaerobiosis; Anthraquinone dyes; Applied sciences; Autoxidation; Azo Compounds - chemistry; Azo Compounds - metabolism; Azo dyes; Bacteria - growth & development; Bacteria - metabolism; Biodegradation, Environmental - radiation effects; Biological and medical sciences; Biological treatment of waters; Biotechnology; Catalysis - radiation effects; Chemical and Process Engineering; Chemical Physics; COD removal; Coloring Agents - chemistry; Coloring Agents - metabolism; Engineering Sciences; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; Industrial applications and implications. Economical aspects; Industrial Waste; Industrial wastewaters; Methane - metabolism; Molecular Structure; Photochemistry; Phthalocyanine dyes; Physics; Pollution; Textile Industry; Titanium - chemistry; Titanium - metabolism; Titanium dioxide; Waste Management - instrumentation; Waste Management - methods; Wastewaters; Water treatment and pollution; Autoxidation; Anthraquinone dyes; Phthalocyanine dyes; Azo dyes; Titanium dioxide; COD removal; Discoloration; Organic dye; Combined process; Anthraquinone dye; Photocatalysis; Biological purification; Anthraquinone dyes,Autoxidation,Azo dyes,COD removal,Phthalocyanine dyes,Titanium dioxide; Phthalocyanine dye; Heterogeneous catalysis; Ultraviolet radiation; Anaerobe; Industrial waste water; Azo dye; Tertiary purification; Physicochemical purification; Waste water purification; Titanium oxide; Photooxidation; Textile industry; Organic compounds; Photochemical degradation
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2008.05.026

A photocatalytic process based on immobilized titanium dioxide was used to treat crude solutions of azo, anthraquinone and phthalocyanine textile dyes. In addition, the process was applied to the treat autoxidized chemically reduced azo dyes, i.e. representatives of recalcitrant dye residues after biological sequential anaerobic–aerobic treatment. Photocatalysis was able to remove more than 90% color from crude as well as autoxidized chemically reduced dye solutions. UV-absorbance and COD were also removed but to a lower extent (50% in average). The end products of photocatalytic treatment were not toxic toward methanogenic bacteria. The results demonstrate that photocatalysis can be used as a pre- or post-treatment method to biological anaerobic treatment of dye-containing textile wastewater.