Treatment of anthraquinone dye wastewater by hydrolytic acidification-aerobic process

Experiment on microbial degradation with two kinds of biological process, hydrolytic acidification-aerobic process and aerobic process was conducted to treat the anthraquinone dye wastewater with COD Cr concentration of 400 mg/L and chroma 800. The experimental result demonstrated that the hydrolytic-aerobic process could raise the biodegradability of anthraquinone dye wastewater effectively. The effluent COD Cr can reach 120170 mg/L and chroma 150 which is superior to that from simple aerobic process.

Electrooxidative Degradation of an Anthraquinone Dye with in-situ Electrogenerated Active Chlorine in a Divided Flow Cell

The purpose of this paper was to investigate the possibility of treating C. I. Reactive Blue 19 wastewater by electrochemical oxidation via electrogenerated active chlorine, using metallic oxide coatings （dimensional stable anode, DSA） as anode. The electrolysis for the simulated wastewater was conducted at a constant current. Absorbances at 592 nm and 255 nm were measured to follow the decolorization of the dye and the degradatin of its aromatic ring. After 4 h of electrolysis under the experimental conditions： current density of 15 A·m^-2, 0.2 mol·L^-1 NaCl, 0.1 mol·L^-1 Na2SO4, 0.1 mmol·L^-1 dye, initial pH=6.4 and T=30℃, 100% decolorization of the dye and about 45% degradation of its aromatic ring were achieved, while no obvious change of total organic carbon was observed. The experimental results suggest that the decolorization of the dye and degradation of its aromatic ring were directly affected by current density, temperature, concentrations of the dye and sodium chloride, while slightly affected by initial pH and sodium sulfate concentration; the decolorization of the dye and degradation of its aromatic ring followed pseudo-first-order kinetics; and indirect electrooxidation, using electrogenerated active chlorine, predominated in the electrochemical oxidation.

Decolorization of Anthraquinone dye by Rhodopseudomonas XL-1

Rhodopseudomonas XL 1 gained from textile wastewater can effectively decolorize anthraquinone dye. Under anaerobic condition, 93 percent of the anthraquinone dye is decolorized , which is higher than that under aerobic condition. The optimum pH is 6～9 and the optimum temperature is 20～40℃ for the anthraquinone dye decolorization by XL 1 . XL 1 can not decolorize the anthraquinone dye when it is the sole carbon source. Microbial cometabolism and decolorization of the dye take place in the presence of some other carbon source(0.2～0.4g/100ml)called cometabolic substrate. The cometabolic substrate can be peptone, glucose, sodium acetate, beef extract, amylum, etc. The change of molecular structure of the dye before and after decolorized by XL 1 is studied by UV Vis absorption spectrum. The results indicate that its molecular structure is changed evidently.

Adsorption of Anthraquinone Dyes from Aqueous Solutions by Penicillium Terrestre

Penicillium terrestre was used for removing four anthraquinone dyes from aqueous solution. The experiments were performed in Erlenmeyer flasks and spore suspension was used for inoculation. The results show that the mechanism of dye removal by penicillium terrestre is biosorption and the growing pellets exhibit higher adsorptive capacity than the resting or dead ones. The maximum removals of disperse blue 2BLN, reactive brilliant blue KN-R, acid anthraquinone blue and bromamine acid at the concentration of 120 mg/L by biosorptionof growing pellets are 10096, 100%, 96% and 91%, respectively. The 100.0% and 91.4% KN-R removals are achieved respectively at the much higher concentration of 250 and 400 mg/L. 2.5 g/L glucose is sufficient for 100% KN-R removal by growing pellets. Salinity （NaCl） increase from 0 to 2% （W/ V） moderately accelerates both mycelium growth and KN-R removal.

Bacterial degradation of anthraquinone dyes

Anthraquinone dyes,which contain anthraquinone chromophore groups,are the second largest class of dyes after azo dyes and are used extensively in textile industries.The majority of these dyes are resistant to degradation because of their complex and stable structures;consequently,a large number of anthraquinone dyes find their way into the environment causing serious pollution.At present,the microbiological approach to treating printing and dyeing wastewater is considered to be an economical and feasible method,and reports regarding the bacterial degradation of anthraquinone dyes are increasing.This paper reviews the classification and structures of anthraquinone dyes,summarizes the types of degradative bacteria,and explores the possible mechanisms and influencing factors of bacterial anthraquinone dye degradation.Present research progress and existing problems are further discussed.Finally,future research directions and key points are presented.