Anaerobic co-digestion of sewage sludge and food waste for hydrogen and VFA production with microbial community analysis

• Published in: Waste management (Elmsford) 2018-08, Vol.78, p.789-799
• Main Authors: Li, Zhipeng, Chen, Zhen, Ye, Hong, Wang, Yuanpeng, Luo, Weiang, Chang, Jo-Shu, Li, Qingbiao, He, Ning
• Format: Article
• Language: English
• Subjects: Anaerobic co-digestion; Food waste; Microbial community composition; Response surface methodology; Sewage sludge
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2018.06.046

[Display omitted] •Co-digestion enhanced H2 content (62.4%, v/v) and VFA production (281.84 mg/g VS).•The mixing of SS and FW improved substrate characteristics for hydrogen and tVFA.•The optimum condition for maximal H2 and tVFA was estimated as 85.17 and 79.87% FW.•Co-digestion promoted growth of the microbes involved in H2 and VFA production. In this study, the anaerobic co-digestion of food waste (FW) and sewage sludge (SS) was investigated for the production of hydrogen and volatile fatty acids (VFAs). The results showed that the anaerobic co-digestion of these materials enhanced the hydrogen content by 62.4% (v/v), 29.89% higher than that obtained by FW digestion alone, and the total VFA production reached at 281.84 mg/g volatile solid (VS), a 8.38% increase. This enhancement was primarily resulted from improvements in the multi-substrate characteristics, which were obtained by supplying a higher soluble chemical oxygen demand (23.78–32.14 g/L) and suitable a pH (6.12–6.51), decreasing total ammonia nitrogen by 18.67% and ensuring a proper carbon/nitrogen ratio (15.01–23.01). Furthermore, maximal hydrogen (62.39 mL/g VS) and total VFA production potential (294.63 mg/g VS) were estimated using response surface methodology optimization, which yielded FW percentages of 85.17% and 79.87%, respectively. Based on a pyrosequencing analysis, the dominant bacteria associated with VFA and hydrogen production were promoted under optimized condition, including members of genera Veillonella and Clostridium and the orders Bacteroidales and Lactobacillales.