title: Optimal decolorization and kinetic modeling of synthetic dyes by Pseudomonas strains.
abstract: Pseudomonas spp were isolated from an anaerobic-aerobic dyeing house wastewater treatment facility as the most active azo-dye degraders. Decolorization of azo dyes and non-azo dyes including anthraquinone, metal complex and indigo was compared with individual strains and a bacterial consortium consisting of the individual strain and municipal sludge (50 50wt). The consortium showed a significant improvement on decolorization of two recalcitrant non-azo dyes, but little effect on the dyes that the individual strains could degrade to a great or moderate extent. Decolorization of Acid violet 7 (monoazo) by a Pseudomonas strain GM3 was studied in detail under various conditions. The optimum decolorization activity was observed in a narrow pH range (7-8), a narrow temperature range (35-40 degrees C), and at the presence of organic and ammonium nitrogen. Nitrate had a severe inhibitory effect on azo dye decolorization: 10 mg/L led to 50% drop in decolorization activity and 1000 mg/L to complete activity depression. A kinetic model is established giving the dependence of decolorization rate on cell mass concentration (first-order) and dye concentration (half order). The rate increased with temperature from 10 to 35 C, which can be predicted by Arrhenius equation with the activation energy of 16.87 kcal/mol and the frequency factor of 1.49 x 10(11) (mg L)1/2/g DCM min.
authors.affiliation: Department of Chemical Engineering, Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, SAR, China. kejianyu@ust.hk
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.forename: P L
authors.initials: PL
authors.lastname: Yue
mesh_terms: D004396:Coloring Agents / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008962:Models, Theoretical; D010858:Pigmentation; D011549:Pseudomonas / Q000502:physiology*; D013696:Temperature; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000378:metabolism*
chemical_list: D004396:Coloring Agents; D014874:Water Pollutants, Chemical