污泥厌氧发酵产酸机理及应用研究进展

Mechanism and Research Progress of Acid Synthesis During Sludge Anaerobic Fermentation

为了实现污水中污泥减量化和资源化,对其进行厌氧消化是目前国际上应用最广泛的处理方法。酸化阶段的重要产物——挥发性脂肪酸(VFAs)不仅可以作为污水脱氮除磷的碳源,还是合成生物质塑料聚羟基脂肪酸酯(PHAs)的理想底物。简单介绍了污泥厌氧发酵产酸的代谢机理和微生物机理,对近年来污泥厌氧发酵产酸的研究成果进行了梳理,重点论述了底物种类、预处理技术、pH值、发酵温度等因素对污泥厌氧发酵产酸的影响及研究进展,总结并对比了不同底物类型、发酵温度、酸性和碱性条件下都可影响发酵产酸的产量及酸种类分布,而污泥预处理技术则倾向于提高酸的产量,对酸种类分布影响不大。介绍了污泥厌氧发酵产酸在合成PHAs、生物能源和污水的脱氮除磷等方面的应用情况。最后,针对污泥厌氧发酵产酸会因底物有机成分不同,导致酸化效率有所差异,同时控制底物种类、pH值和温度等因素不仅影响产酸量,还会影响产酸类型和产物种类。提出了今后的研究方向主要是深入分析不同底物的酸化效率差异原因、污泥定向发酵产酸,实现总VFAs中各种酸比例调控。

In order to achieve the reduction and recycling, anaerobic digestion of sludge is the most widely used treatment method in the world. Volatile fatty acids(VFAs), an important product in acidification stage, could be used to remove nitrogen and phosphorous from wastewater as carbon sources, and to synthesize valuable products,such as bioplastics polyhydroxyalkanoates(PHAs). Metabolic mechanism and microbial mechanism of acidogenesis process during sludge anaerobic fermentation were introduced. The research results of anaerobic fermentation of sludge in recent years were reviewed systematically. The effects of substrate species, pretreatment technology, pH value and fermentative temperature on the acid production by anaerobic fermentation of sludge and its research progress were discussed. Temperature and pH value obtained more attention and it was summarized and compared the acid production by sludge fermentation under different substrate types, temperature, acid and alkaline conditions could affect the production and type distribution, while sludge pretreatment technology tended to increase the production of acid, but had little effect on the type distribution. The application of anaerobic fermentation in the synthesis of PHAs, bioenergy, nitrogen and phosphorus removal from sewage was also introduced. Finally, due to the different organic compoments of the substrate, the acidification efficiency would be different. Meanwhile, controlling the substrate type, pH value and temperature would not only affect the acid production, but also affect the acid production type. Therefore, the research directions of further study were given as the reasons for differences in acidification efficiency of different substrates, directional fermentation of sludge to produce acid, and achieving the regulation of various acids proportions in total VFAs.