| Because of its adhesion, wear resistance, oil resistance and strong chemical stability, polyvinyl alcohol (PVA) is widely used in film, fiber slurry, paper industry and even the automobile industry. China is a big textile country, and there are more than30,000tons sizing material just as PVA are used in dyeing process of the textile industry every year, so that wastewater of PVA accounting for half of all printing and dyeing wastewater. However, Due to the bad biochemical property and long biodegradable cycle, large number of bubbles formed in the surface of the water environment, PVA has caused serious environment pollution. In all of the PVA wastewater treatment, biological method is a way now to pay more attention at home and abroad. Biological method own free of secondary pollution and better results for treatment of PVA, so isolated and screened PVA-degrading strains and studied the degradation effects of PVA is vary important.In early days of this subject, we got a kind of mixed strains, which could completely degradate PVA. All of this mixed strains were isolated and screened from the sample (black massive) which was was carried from the bottom of the thick liquid yarn machine sink in a dyeing factory. After expanding culture of this mixed strains, we investigated the effect of starch on the degradation capacity in the flask culture. The PVA degradation efficiency of2g/L for the fermentation broth of PVA:starch concentration ratio is1:1,1:2,1:3were measured, and analyzed starch degrading bacteria influence of PVA. Results showed that the concentration of starch had a great influence on PVA degradation, and it hindered the of the mixed strains on PVA.Using the method of dilted coating to screen the isolated and saved mixed strains, we got eight single strains, and determined the genus of them through the physiological and biochemical experiments. We got two kinds of Spp., two kinds of Pseudomonas sp., one kind of Xanthomonas, one kind of Micrococcus, one kind of Streptoccus, and one kind of Genus Lactobacillus. Sented five of the eight single strains, through the method of16SrDNA sequenced, we could sure that two of them was Pseudomonas aeruginosa, one was Stenotrophomonas acidaminiphila, one was Acinetobacter baumannii, and the last one was similar of Acinetobacter baumannii. Analysised the PVA degradation effect of this eight kinds of single strains, and showed that the effects were vary. Remixed the eight single strains, the PVA degradation effect was worse than the mixed strains.Using polyvinyl alcohol (PVA) and starch as carbon source, of which the concentration ratio was1:2, to prepare the simulated water. The hydrolysis acidification-aerobic process was used to research the degradation of substances such as polyvinyl alcohol (PVA). Research results show that the degradation of Chemical oxygen demand (COD), polyvinyl alcohol (PVA), and starch when the Hydraulic retention time (HRT) of the acid hydrolysis poo was24h, was better than the HRT was12h. When the HRT was24h, After added two dyes such as reactive brilliant red and reactive blue in the simulated wastewater, the treatment effects of COD and PVA were slightly lower, yet the treatment effects of the starch was still high. Analysised removal efficiency of the acid hydrolysis pool and the aerobic pool, and in the acid hydrolysis poo removal efficiency of the biodegradable substances such as PVA and starch was more than70%, and in which macromolecules could well be broken down into small molecules. So, this hydrolysis acidification-aerobic process will has a good deal of the PVA wastewater. |
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