The testing of several biological and chemical coupled treatments for Cibacron Red FN-R azo dye removal.
Several biological and chemical coupled treatments for Cibacron Red FN-R reactive azo dye degradation have been evaluated. Initially, a two-stage anaerobic-aerobic biotreatment has been assessed for different dye concentrations (250, 1250 and 3135 mg l(-1)). 92-97% decolourisation was attained during the anaerobic digestion operating in batch mode. However, no dissolved organic carbon (DOC) removal neither biogas production was observed during the process, indicating that no methanogenesis occurred. Additionally, according to Biotox and Zahn-Wellens assays, the anaerobically generated colourless solutions (presumably containing the resulting aromatic amines from azo bond cleavage) were found to be more toxic than the initial dye as well as aerobically non-biodegradable, thus impeding the anaerobic-aerobic biological treatment. In a second part, the use of an advanced oxidation process (AOP) like photo-Fenton or ozonation as a chemical post-treatments of the anaerobic process has been considered for the complete dye by-products mineralisation. The best results were obtained by means of ozonation at pH 10.5, achieving a global 83% mineralisation and giving place to a final harmless effluent. On the contrary, the tested photo-Fenton conditions were not efficient enough to complete oxidation.
Departament de Química, Edifici Cn, Universitat Autònoma de Barcelona, E-08193 Bellaterra, Barcelona, Spain.
Julia
J
García-Montaño
Xavier
X
Domènech
José A
JA
García-Hortal
Francesc
F
Torrades
José
J
Peral
D000332:Aerobiosis; D048908:Aliivibrio fischeri / Q000187:drug effects / Q000378:metabolism; D000693:Anaerobiosis; D001391:Azo Compounds / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects / Q000633:toxicity; D001673:Biodegradation, Environmental; D004396:Coloring Agents / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects / Q000633:toxicity; D006861:Hydrogen Peroxide / Q000737:chemistry; D007501:Iron / Q000737:chemistry; D049449:Luminescence; D016877:Oxidants / Q000737:chemistry; D010126:Ozone / Q000737:chemistry; D014466:Ultraviolet Rays; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000378:metabolism / Q000528:radiation effects / Q000633:toxicity
D001391:Azo Compounds; D004396:Coloring Agents; D016877:Oxidants; D014874:Water Pollutants, Chemical; D010126:Ozone; D006861:Hydrogen Peroxide; D007501:Iron