特色纤维原料制浆造纸全质化专刊投稿US-FNA联合预处理污泥强化厌氧消化的机制解析

Mechanism analysis of enhanced anaerobic digestion of US-FNA combined pretreatment sludge

关键词:  超声  游离亚硝酸  剩余污泥预处理  厌氧消化

Key Words:Ultrasound  Free nitrous acid  Excess activated sludge pretreatment  Anaerobic digestion

摘要:污泥絮体与细胞膜对胞外水解的阻隔造成污泥厌氧消化周期长、甲烷产量低。超声和游离亚硝酸能够在温和条件下实现污泥有机物溶出及絮体分散，但两种预处理是否存在协同作用尚未可知。因此，本研究对游离亚硝酸与超声联合预处理对于污泥有机质溶出、絮体分散、细胞内容物质释放及产甲烷性能的作用进行评估。结果表明，超声预处理的主要作用是絮体分散与胞外聚合物溶出，游离亚硝酸预处理则是细胞内容物质释放。超声-游离亚硝酸预处理后污泥甲烷产量较未经处理增加了37.1 %，分别达到游离亚硝酸组的1.08倍和超声组的1.07倍，但超声与游离亚硝酸二者在联合预处理中所发挥作用各自独立，并未发现明显的协同增效作用。引入游离亚硝酸在会降低污泥厌氧消化初期产气速率，未对累积产气量造成显著影响。根据发酵后污泥微生物菌群的解析，发现游离亚硝酸是影响污泥微生物多样性的主导因素。

Abstract:The prolonged period of anaerobic digestion and reduced methane production were observed due to the inhibition of extracellular hydrolysis caused by sludge floc and cell membrane. The potential synergistic effect of combining ultrasonic and free nitrous acid pretreatment procedures remains uncertain, despite their ability to produce organic dissolution and floc dispersion of sludge under mild circumstances. Hence, the present study aimed to assess the impact of the combination of free nitrous acid and ultrasonic pretreatment on many aspects of sludge, including the dissolution of organic matter, dispersion of flocs, release of cellular contents, and methanogenic performance. The findings indicated that the primary impact of ultrasonic pretreatment was the dispersion of flocs and the dissolution of extracellular polymeric substances, whereas the pretreatment with free nitrous acid resulted in the release of cell content. In comparison to the no-treatment control, the generation of sludge methane exhibited a significant increase of 37.1%. Specifically, the free nitrous acid group demonstrated a 1.08-fold increase, while the ultrasonic group had a 1.07-fold rise. Nevertheless, the combined pretreatment of ultrasonic and free nitrous acid exhibited distinct roles, and no apparent synergistic impact was seen. The incorporation of free nitrous acid has the potential to decrease the rate of gas generation during the initial phase of anaerobic digestion of sludge. However, it does not exert a substantial impact on the overall gas output over time. The examination of microbial flora in sludge following fermentation revealed that the presence of free nitrous acid has a significant influence on the variety of microorganisms in the sludge.