Efficient biorefinery of waste activated sludge and vinegar residue into volatile fatty acids: Effect of feedstock conditioning on performance and microbiology
Efficient biorefinery of waste activated sludge and vinegar residue into volatile fatty acids: Effect of feedstock conditioning on performance and microbiology
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DOI：
10.1039/c8ew00266e
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发表时间：
2018-10
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通讯作者：
Aijuan Zhou;Zhihong Liu;C. Varrone;Yunbo Luan;Wenzong Liu;Aijie Wang;Xiuping Yue
中科院分区：
文献类型：
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作者：
Aijuan Zhou;Zhihong Liu;C. Varrone;Yunbo Luan;Wenzong Liu;Aijie Wang;Xiuping Yue
羧酸，特别是短链（C2和C3）脂肪酸，是许多生物过程的优选碳源。从废弃活性污泥中回收挥发性脂肪酸的生产效率受到营养成分不平衡的限制。在这项研究中，一种低成本的替代方法（即，与醋渣（VR）共消化）以提高从WAS中回收C2-C3 VFAs。与单独的WAS消化相比，与热辅助碱（TA）、氢氧化铵（AH）和硫酸（SA）预处理的VR共同消化时，总VFA（C2-C5）浓度分别增加了187%、74%和44%。基于组成分析，这种改进主要是由于C2-C3 VFA的产生。共消化试验中的水解速率常数，例如，kh_TA = 0.0045 h-1，也高于单消化期间观察到的（0.0018 h-1）。添加VR大大增加了WAS的水解，特别是与TA，从而增强了随后的酸化过程。高通量测序表明，某些组的微生物（特别是水解和产酸细菌），如醋酸杆菌，破蛋白，Cloacibacillus，不动杆菌和芽孢杆菌，富集在WAS和VR共消化。典型相关分析的进一步研究表明，特征调理的消化原料是一个有效的策略，以重组固有的微生物群落在WAS。在这项研究中提出的概念可能是切实可行的，同时减少运营，污泥运输和处置成本的污水处理厂。
Carboxylic acids, particularly short chain (C2 and C3) fatty acids, are the preferable carbon source for many bioprocesses. Production efficiency of volatile fatty acids (VFAs) recovery from waste activated sludge (WAS) is limited by unbalanced nutrient components. In this study, a low-cost alternative approach (i.e., co-digestion with vinegar residue (VR)) to enhance C2–C3 VFAs recovery from WAS is reported. Compared to sole WAS digestion, concentration of total VFAs, C2–C5, increased by 187%, 74% and 44%, when co-digested with thermal-assisted alkaline (TA), ammonium hydroxide (AH) and sulfuric acid (SA) pretreated VR, respectively. Based on composition analysis, this improvement was mainly due to C2–C3 VFAs production. The hydrolysis rate constants in co-digestion tests, e.g., kh_TA = 0.0045 h−1, were also higher than that observed during mono-digestion (0.0018 h−1). Addition of VR greatly increased the hydrolysis of WAS, particularly with TA, thus enhancing the subsequent acidification process. High-throughput sequencing illustrated that certain groups of microbes (particularly hydrolytic and acid-producing bacteria), such as Acetobacterium, Proteiniclasticum, Cloacibacillus, Acinetobacter and Gemmobacter, were enriched in WAS and VR co-digestion. Further investigation of canonical correlation analyses showed that characteristic conditioning of digestion feedstock was an efficient strategy to restructure the inherent microbial community in WAS. The proposed concept in this study may be practical to simultaneously reduce operational, sludge transport and disposal costs of WWTPs.