reactive-blue-21 and phthalocyanine

Cellulose fabrics were modified with a derivative of copper phthalocyanine (Reactive Blue C.I. 21) by dyeing method. The modified cellulose fabrics exhibited important photoactive property, such as the hydroxyl radicals-generating ability. The UV-vis spectrum, exhaustion rate, fixation rate and grafting quantity of Reactive Blue 21 on the cellulose fabrics were measured and calculated. The chemical structure and morphology of the modified cellulose were characterized. The amount of the produced hydroxyl radicals was measured and the photoactive mechanism was discussed. The UV light-induced antibacterial performance of the modified materials was measured. The modified cellulose exhibited photo-induced antibacterial activity against both Staphylococcus aureus and Escherichia coli.

Topics: Anti-Bacterial Agents; Cellulose; Escherichia coli; Indoles; Isoindoles; Metalloporphyrins; Staphylococcus aureus; Textiles; Ultraviolet Rays

The decolorization of two anthraquinone dyes (Reactive Blue 4 [RB4] and Reactive Blue 19 [RB19]) and two phthalocyanine dyes (Reactive Blue 7 [RB7] and Reactive Blue 21 [RB21]) was investigated at an initial dye concentration of 300 mg/L using an unacclimated, enrichment culture. The culture was fed a mixture of organic compounds and maintained initially under aerobic conditions, and then progressively developed anoxic/ anaerobic conditions. Biotransformation-related decolorization of the dyes did not take place under aerobic conditions, but use of the feed organic mixture and biomass production by the enrichment culture were not affected. Complete ammonia removal occurred in the control and all dye-amended cultures. The development and extent of nitrification were much lower in the latter cultures, in which ammonia removal via air stripping was the dominant mechanism. Prolonged incubation of the culture under anoxic/anaerobic conditions with multiple carbon source additions resulted in a high decolorization extent of anthraquinone dyes (over 84%) and only partial decolorization of phthalocyanine dyes (49 to 66%). Development of significant methanogenic activity took place in the control and, to a lesser extent, in the two phthalocyanine dye-amended cultures, but the anthraquinone dyes severely inhibited the development of methanogenic activity. The RB4 and RB19 decolorization was attributed to nonreversible, microbially mediated dye transformation(s), demonstrated by the accumulation of decolorization products with absorbance maxima in the 420- to 460-nm region. The decolorization of RB4 and RB19 followed Michaelis-Menten kinetics. At an initial dye concentration of 300 mg/L, the observed maximum decolorization rate per unit biomass was 9.1 and 37.5 mg dye/mg volatile suspended solids x day for the RB4 and RB19, respectively. Thus, partial decolorization of reactive phthalocyanine dyes and extensive biological decolorization of reactive anthraquinone dyes is feasible only under anoxic/anaerobic conditions.

Topics: Anthraquinones; Bacteria, Aerobic; Bacteria, Anaerobic; Biodegradation, Environmental; Biomass; Coloring Agents; Indoles; Isoindoles; Metalloporphyrins; Methane; Oxidation-Reduction; Textile Industry; Triazines; Waste Management; Water Pollutants, Chemical; Water Purification

The biological decolorization of two industrial, spent textile reactive dyebaths was investigated using a suspended-growth, halophilic mixed culture fed with glucose. Dyebath I contained mainly Reactive Blue 19 (RB19), an anthraquinone dye, whereas dyebath II contained mainly Reactive Blue 21 (RB21), a phthalocyanine dye. Batch assays under anaerobic conditions with the two neutralized dyebaths resulted in 87 and 37% extent of decolorization for dyebaths I and II, respectively. The rate of glucose utilization and the extent of acetate production were impacted in the presence of each dyebath as compared to the control culture. However, dyebath decolorization occurred despite moderate culture inhibition. Reuse of a biologically renovated RB19-containing dyebath in the dyeing process resulted in reproducible but not identical cotton fabric shades as compared to a standard dyeing (i.e., control) using fresh water. This difference is attributed to a variable degree of RB19 aggregation during the dyeing process and is not related to the efficiency of the biodecolorization process. Further improvement of the redyeing efficiency will lead to the development of an in-plant, closed-loop decolorization system resulting in significant water conservation and minimization of textile pollutants such as salt and dyes.

Topics: Anthraquinones; Bacteria, Anaerobic; Color; Coloring Agents; Conservation of Natural Resources; Indoles; Industrial Waste; Isoindoles; Metalloporphyrins; Sodium Chloride; Textile Industry; Waste Disposal, Fluid; Water Pollutants, Chemical; Water Purification