糖蜜酒精废水的生物脱色及其细菌群落结构分析

Decolorization of Molasses Alcohol Wastewater and Analysis of Bacterial Colonies Structure

糖蜜酒精废水是糖厂利用糖蜜生产酒精后的废液,废水中色素的含量较高,脱色为该类废水处理过程中的一大难题。采用富集培养技术,将取自糖厂IC(internal circulation)反应器底部的活性污泥加入到不同浓度废水中进行富集,得到的菌群可使废水脱色24%、COD(chemical oxygen demand)去除率19.2%。为了提高菌群的脱色能力,研究了几种单因素对菌群生长、脱色及COD去除能力的影响,结果发现,菌群使废水脱色和去除COD的最佳条件为:10%(v/v)废水中添加0.5%葡萄糖、0.1%蛋白胨、0.1%KH2PO4、0.05%MgSO4·7H2O、0.05%KCl,废水初始pH7.0,在37℃培养7d,废水脱色率达46.2%、COD去除率为38.5%。为了了解以上条件下菌群的群落结构,采用分子生态学方法构建了菌群中细菌16S rDNA文库并对代表性的克隆进行了测序,结果显示其中细菌主要分布在Firmicutes、Proteobacteria、Bacteroidetes的7个目中,分别是Erysipelotrich-ales、Clostridiales、Lactobacillales、Xanthomonadales、Burkholderiales、Enterobacteriales、Bacteroidales。大多数细菌属于发酵型细菌,化能异氧型。本研究结果为利用微生物调控糖蜜酒精废水的生物处理提供了依据。

Molasses alcohol wastewater is the wastewater after production of alcohol by molasses in sugar refinery. High pigment content exists in the molasses alcohol wastewater, decolorization is a challenge in wastewater treatment process. Using different concentrations of wastewater as the sole carbon and nitrogen sources, we enriched the activated sludge taken from the bottom of IC reactor in sugar factory, and got a consortium which exhibited 24% decolourization and 19.2% COD reduction. To further enhance decolorization of the consortium, several factors had been considered for the effect on consortium growth, decolorization rate and COD removal ability. The results showed that the highest decolorization yield of 46.2% and 38.5% COD reduction were obtained when cultivated at 37~C for 7 days in 10% （v/v） wastewater containing 0.5% glucose, 0.1% yeast extract, 0.1% KH2PO4, 0.05% MgSO4 ~THzO, 0.05% KC1 and the pH adjusted to 7.0. In order to understand the bacterial community structure in the processing system under the optimized situations, the bacterial 16S rDNA clone library was constructed, and the representative clones were sequenced. The results showed that the bacterial community was mainly distributed in Erysipelotrichales, Clostridiales, Lactobacillales, Xanthomonadales, Burkholderiales, Enterobacteriales, Bacteroidales ofFirmicutes, Proteobacteria, Bacteroidetes. Most of the bacteria is fermented bac- teria, of heterotrophic type. The experimental results provided a basis for the use of microbial control to treat molasses alcohol wastewater by biological methods.