Article,
Novel strategy for efficient energy recovery and pollutant control from sewage sludge and food waste treatment
Contributors
Yuan, Zengwei W
0000-0002-6533-4170
(Corresponding author)
[1]
Xie, Sheng-Yu
0000-0002-3893-4082
[2]
Zhang, Yifeng
0000-0002-2832-2277
[3]
Affiliations
- [1] Nanjing University [NORA names: China; Asia, East];
- [2] CAS Key Laboratory of Urban Pollutant Conversion [NORA names: China; Asia, East];
- [3] Technical University of Denmark [NORA names: DTU Technical University of Denmark; University; Denmark; Europe, EU; Nordic; OECD]
Abstract
Considering the high organic matter contents and pollutants in sewage sludge (SS) and food waste (FW), seeking green and effective technology for energy recovery and pollutant control is a big challenge. In this study, we proposed a integrated technology combing SS mass separation by hydrothermal pretreatment, methane production from co-digestion of hydrothermally treated sewage sludge (HSS) centrate and FW, and biochar production from co-pyrolysis of HSS cake and digestate with heavy metal immobilization for synergistic utilization of SS and FW. The results showed that the co-digestion of HSS centrate with FW reduced the NH4+-N concentration and promoted volatile fatty acids conversion, leading to a more robust anaerobic system for better methane generation. Among the co-pyrolysis of HSS cake and digestate, digestate addition improved biochar quality with heavy metals immobilization and toxicity reduction. Following the lab-scale investigation, the pilot-scale verification was successfully performed (except the co-digestion process). The mass and energy balance revealed that the produced methane could supply the whole energy consumption of the integrated system with 26.2 t biochar generation for treating 300 t SS and 120 t FW. This study presents a new strategy and technology validation for synergistic treatment of SS and FW with resource recovery and pollutants control.
