超声联合生物酶强化污泥发酵产酸及微生物群落分析

Acid Production and Microbial Community of Sludge Fermentation Enhanced by Ultrasound Combined with Bioenzymes

为探究超声和生物酶联用强化剩余污泥发酵产酸的效果,通过分析污泥性质、VSS去除率、挥发性脂肪酸(VFAs)产量和组成以及微生物群落变化,确定最佳污泥处理条件。结果表明,经超声处理后,上清液SCOD、TN和TP浓度显著提高,污泥粒径减小,比表面积增大。超声联合复合酶促进污泥水解和产酸效果最佳,VSS去除率最高达到44.2%,VFAs产量达1209.2 mg/L,其中乙酸为736.3 mg/L。微生物测序结果表明,经超声联合生物酶(复合酶和溶菌酶)处理后的微生物丰度和多样性明显降低。从门水平上看,厚壁菌门(Firmicutes)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes)等水解产酸菌门在复合酶污泥中占主导地位;从属水平上看,梭状芽孢杆菌属(Clostridium_sensu_stricto_11)、丙酸螺菌属(Propionispira)和醋酸杆菌属(Acetobacter)等水解产酸菌属的丰度均与空白对照组有显著差异。

This paper determined the optimal sludge treatment conditions by analyzing the sludge properties,VSS removal rate,volatile fatty acids(VFAs)yield,composition and microbial community changes,so as to investigate the acid production in the fermentation of excess sludge enhanced by ultrasound combined with bioenzymes.After ultrasonic treatment,the SCOD,TN and TP in the supernatant increased significantly,the particle size of sludge decreased,and the specific surface area of sludge increased.Ultrasound combined with composite enzymes demonstrated the best performance for promoting sludge hydrolysis and acid production.The VSS removal rate reached 44.2%,and the VFAs concentration was 1209.2 mg/L,of which the acetic acid concentration was 736.3 mg/L.The results of microbial sequencing showed that the abundance and diversity of microorganisms decreased significantly after ultrasound combined with bioenzymes(composite enzyme and lysozyme)treatment.At the phylum level,the sludge treated with composite enzyme were dominated by hydrolytic acid‑producing bacteria such as Firmicutes,Proteobacteria and Bacteroidetes.At the genus level,the abundances of hydrolytic acid‑producing bacteria such as Clostridium_sensu_stricto_11,Propionispira and Acetobacter were significantly different from those of the blank group.