厌氧发酵液中溶解性有机物对活性污泥合成聚羟基脂肪酸酯影响的研究进展

A review on polyhydroxyalkanoates synthesis in activated sludge system: the effects of dissolved organic compounds by using anaerobic fermentation liquid from waste activated sludge

摘要:

利用活性污泥微生物将剩余污泥发酵液中的挥发性脂肪酸 (Volatile fatty acids，VFAs) 转化为聚羟基脂肪酸酯 (Polyhydroxyalkanoates，PHA) 是目前环境生物技术领域的研究热点。但针对发酵液中非VFAs物质 (主要是溶解性有机物，Dissolved organic matter，DOM) 对活性污泥合成PHA的影响目前仍未有统一的结论，需要进行较全面的分析和总结。因此，文中首先介绍了剩余污泥发酵液中DOM的主要特性及常见分析方法，然后从微生物学、代谢调控、污泥性质等角度分析了DOM中几种主要组分 (多聚糖、蛋白类物质、腐殖质) 对活性污泥合成PHA的影响。综合各研究结果表明高浓度DOM不利于PHA的生产，但适量DOM的存在有利于污泥性质的稳定，同时能降低PHA提纯成本。最后提出了相应的策略来实现对活性污泥利用DOM合成PHA的调控，以期为高效利用厌氧发酵液中DOM实现PHA合成提供解决思路。

关键词:厌氧发酵，溶解性有机物，聚羟基脂肪酸酯，活性污泥，代谢途径

Abstract:

Polyhydroxyalkanoates (PHA) synthesis by activated sludge using volatile fatty acids (VFAs) in fermentation liquid of excess sludge as carbon source is a hotspot in the field of environmental biotechnology. However, there is no unified conclusion on the effects of non-VFAs, mainly dissolved organic matter (DOM), on PHA production. Thus, this critical review mainly introduces the main characteristics and common analysis methods of DOM in anaerobic fermentation liquid. The effects of DOM on PHA production are analyzed from the aspects of microbiology, metabolic regulation and sludge properties. The results of different studies showed that high concentration of DOM is bad for PHA production, but an appropriate amount of DOM is conducive to the stability of sludge properties, reducing the final PHA purification cost. Finally, suitable strategies were proposed to regulate the PHA synthesis by activated sludge with DOM for PHA production by anaerobic fermentation liquid.

Key words:anaerobic fermentation, dissolved organic matter (DOM), polyhydroxyalkanoates (PHA), activated sludge, metabolic pathway