Electricity production and nutrient recovery from waste activated sludge via microbial fuel cell and subsequent struvite crystallization: Effect of low temperature thermo-alkaline pretreatment

• Published in: Bioresource technology 2024-12, Vol.414, p.131575, Article 131575
• Main Authors: Wei, Lin, Li, Ziyue, Hong, Tianqiu, Zhang, Qiang, Luo, Lei, Tang, Yiming, Ji, Junjie, Kong, Jianyu, Ding, Xiaoke
• Format: Article
• Language: English
• Subjects: Alkalies - chemistry; Bioelectric Energy Sources; Cold Temperature; Crystallization; Electricity; Hydrogen-Ion Concentration; Magnesium Compounds - chemistry; Microbial fuel cell; Nutrients; Phosphate buffer solution; Phosphates - chemistry; Sewage; Struvite; Struvite - chemistry; Temperature; Thermo-alkaline pretreatment; Waste activated sludge
• ISSN: 0960-8524; 1873-2976; 1873-2976
• DOI: 10.1016/j.biortech.2024.131575

[Display omitted] •Low temperature thermo-alkaline pretreatment facilitated the release of nutrient and organics from waste activated sludge.•The thermo-alkaline pretreatment improved the output performance of microbial fuel cell.•Pretreated waste activated sludge had phosphate buffering function for MFC operation.•The thermo-alkaline pretreatment affected microbial community structure of the anode biofilm.•The thermo-alkaline pretreatment enhanced nutrient recovery from wasted activated sludge. Microbial fuel cell (MFC) and subsequent struvite crystallization are available low-carbon environmental- friendly techniques for resource utilization of waste activated sludge (WAS). In this study, low temperature thermo-alkaline pretreatment (LTTAP) was innovatively proposed for enhancing MFC electricity generation and subsequent struvite crystallization from WAS. The results indicated that LTTAP at 75 °C and pH 10 not only substantially shortened the start-up time of MFC to 3–4 days, but also significantly increased maximum power density to 5.38 W/m3. Moreover, thermo-alkaline pretreated WAS effectively exhibited stable and high output voltage over long period, compared to unpretreated WAS. Furthermore, pretreated WAS can provide an effective pH buffering function for MFC operation. In addition, about 90 % of phosphate in the pretreated WAS supernatant was recovered by struvite crystallization. The findings herein provided a new route for enhancing electricity production and nutrient recovery from WAS, which can realize the full-scale applicationof WAS resource utilization.