超声波-游离亚硝酸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

本研究对超声波(US)预处理、游离亚硝酸(FNA)预处理及超声波-游离亚硝酸(USFNA)联合预处理对于污泥有机质溶出、絮体分散、细胞内容物释放及产甲烷性能的作用进行评估。结果表明,US预处理的主要作用是使絮体分散与胞外聚合物溶出,FNA预处理则是使细胞内容物释放。US-FNA联合预处理后,污泥甲烷产率较未预处理增加了37.1%,分别达到US预处理的1.07倍和FNA预处理的1.08倍,但US与FNA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FNA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FNA是影响污泥微生物多样性的主导因素。

In this study,the effects of ultrasonic(US)pretreatment,free nitrous acid(FNA)pretreatment and ultrasonic-freenitrous acid(US-FNA)combined pretreatment on many aspects of sludge,including the dissolution of organic matter,dispersion of flocs,release of cel‐lular contents,and methanogenic performance.The results showed 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%.Specifical‐ly,the ultrasonic group demonstrated a 1.07-fold increase,while the free nitrous acid group had a 1.08-fold rise.Nevertheless,the com‐bined pretreatment of ultrasonic and free nitrous acid exhibited distinct roles,and no apparent synergistic impact was seen.The incorporation of free nitrous acid had the potential to decrease the rate of gas generation during the initial phase of anaerobic digestion of sludge.However,it did not exert a substantial impact on the overall gas output over time.The examination of microbial flora in sludge following fermentation re‐vealed that the presence of free nitrous acid had a significant influence on the variety of microorganisms in the sludge.