Study Of Biotoxicity Changes Of Dyes During Fenton Oxidation And Biodegradation

With the continuous development of dye and dyeing and printing industry, dye has been used widely in paper mills, textile industry, cosmetics industry and other industries. The wastewater generated has brought great harm to the environment. Among them, dye is one of the most important pollutants in dyeing wastewater. So, how to degrade dye effectively is crucial. Dyeing wastewater by fenton oxidation and biological method may produce toxic substances. Conventional physical and chemical indicators can not reflect fully its comprehensive effects. So, this study was aimed at detecting acute toxicity, genotoxicity and antiestrogenic activity combined with biological toxicity test methods. Excitation-emission matrix fluorescence spectroscopy was used to chacterize the chemical structure of the samples by different treatment methods and detect the products by gas chromatography mass spectrometry technology. It can provide reference for comprehensive evaluation of dyeing wastewater’ treatment effect.In this study, anthraquinone dye Reactive Blue 19, Acid Blue 80 and Acid Green 25, azo dye Reactive Black 5, Direct Red 28 and phthalocyanine dye Reactive blue 21 were degradated by fenton oxidation. Acute fish toxicity test was used to detect different dyes. In addition, Reactive Black 5, Reactive Blue 19 and dye mixtures by fenton oxidation were pretreated using a solid phase extraction method. And the genotoxic effects and antiestrogenic activities of the samples were detected by means of a SOS/umu assay and a yeast two-hybrid assay, respectively. At the same time, genotoxic effects and antiestrogenic activities of Reactive Black 5 and Reactive Blue 19 by bacterial consortium FF degradating were detected. At last, genotoxic effects and antiestrogenic activities of simulated wastewater(including Reactive Black 5 and Reactive Blue 19) during anoxic-aerobic treatment were detected, too. Chemical structures of the samples were chacterized by excitation-emission matrix fluorescence spectroscopy and degradation products were detected by gas chromatography mass spectrometry technology.The results indicated: 1)The 96 h LC50 of acid blue 80 is 137.7 mg/L by means of acute fish toxicity test, lower than other five kinds of dyes. It turned out that acute toxicity of acid blue 80 was more than other five kinds of dyes. The test revealed that acute toxicity of Reactive Blue 19, Reactive Black 5, Acid Blue 80 and Acid Green 25 was less than before fenton oxidation, acute toxicity of Reactive blue 21 and Direct Red 28 is more than before fenton oxidation. 2)For genotoxicity, Reactive Black 5, Reactive Blue 19 and dye mixtures before and after fenton oxidation were no genotoxic. Besides, the genotoxicity study revealed that no genotoxicity was detected of Reactive Black 5 before and after the biotreatment by the bacterial consortium FF. In contrast, no genotoxicity of Reactive Blue 19 was detected before the biodegradation, however, the genotoxicity could be detected after the biodegradation for 24 h and 48 h, under high concentration multiples. No genotoxicity of simulated wastewater during anoxic-aerobic treatment was detected. 3)For antiestrogenic activity test, antiestrogenic activities of dye samples by fenton oxidation were reduced, antiestrogenic activities of dye samples by bacterial consortium FF were increased. For simulated wastewater during anoxic-aerobic treatment, antiestrogenic activity of anoxic effluent increased and antiestrogenic activity of aerobic effluent were less than the original water. 4)Chemical structures of the dye samples by fenton oxidation and by bacterial consortium FF were changed through excitation-emission matrix fluorescence spectroscopy. Degradation products were analyzed by gas chromatography mass spectrometry technology. Phenol was detected by bacterial consortium FF degradating dyes and phenol was genotoxic. However, substances related to antiestrogenic activity were undetectable by these two methods. Diethyl phthalate and Diisobutyl phthalate were estrogenic effect by some reports, and they were detected from fenton oxidation dyes.