废物乙醇化处理进展

废物乙醇发酵是废物资源化的途径之一,包括废物的预处理,乙醇发酵菌株的选育,乙醇发酵新技术,新工艺的采用等重要内容。同酵母发酵乙醇相比,利用细菌发酵产乙醇具有产率和转化率高,平均发酵速度快等优点,是研究的热点之一,特别是热纤核菌和热糖核菌能直接发酵纤维类废物为乙醇,它们的发现使纤维类废弃物的资源化向前迈进了一大步。同时,人们利用基因工程的手段,改变原菌株的遗传物质,构建“超级菌”,来满足乙醇发酵的要求,同一般发酵技术相比,细胞固定化拄术具有使发酵过程连续运行又具有细胞浓度大,产乙醇效率高等优点。有效的乙醇分离技术包括分离膜、萃取、真空等,它们能降低发酵液中乙醇的浓度,保证酵母的发酵活性,从而提高乙醇的产量。因此,废物乙醇化技术是一个具有巨大潜力的处理废物的新领域。

PROGRESS IN FERMENTATION OFWASTES INTO ETHANOL

ermentation of wastes into ethanol is a method for utilization of waste resources,mainly including waste pretreatment , screening of microbial strains for ethanol fermentationand use of new technology and new methods for ethanol fermentation. In comparison withyeast, bacteria in use for fermentation of wastes into ethanol can have high productivity,transfer efficiency and fermentation speed. Bacteria are major reseach aim. The use ofClostridium thermocellum and Clostridium thermosacchardytium for direct fermentation of fi-brous wastes into ethanol provides a possibility for utilization of fibrous wastes. The micro-bial strains with its hereditary substance changed by genetic technology to crcate a species of"superbacteria" may meet the need for ethanol fermentation. As compared with convention-al technology , the cell- fixation technology has advantages in continuous fermentation , highcell concentration and fermentation effecency. Membrane, extraction and vacums are themethods for efficient ethanol separation in whcih ethanol concentration can be reduced in fer-mentation liquor and the yeast activity can be maintained so that the ethanol yield can be in-creased. The technology of fermentation of waste into ethanol is a new area of waste treat-ment.