Long-term evaluation of the anaerobic co-digestion of food waste and landfill leachate to alleviate ammonia inhibition. (15th October 2022)

• Record Type: Journal Article
• Authors: Peng, Yun; Li, Lei; Yuan, Wenduo; Wu, Di; Yang, Pingjin; Peng, Xuya
• Is Part Of: Energy conversion and management. Volume 270(2022)
• Publication Date: 2022-10-15
• Subjects: Ammonia stress -- Food waste -- Landfill leachate -- Microbial community -- PICRUSt; AD Anaerobic digestion -- FW food waste -- VFA volatile fatty acid -- LL landfill leachate -- VS volatile solid -- OLR organic loading rate -- TS total solid -- TAN total ammonia nitrogen -- VSS volatile suspended solid -- CSTR continuous stirred tank reactor -- HRT hydraulic retention time -- TVFA total volatile fatty acid -- TA total alkalinity -- GI germination index -- FAN free ammonia nitrogen -- EPS extracellular polymeric substance -- MMC methylmalonyl-CoA -- SAO syntrophic acetate oxidation -- WL Wood-Ljungdahl -- GCS glycine cleavage system; Direct energy conversion -- Periodicals; Energy storage -- Periodicals; Energy transfer -- Periodicals; Énergie -- Conversion directe -- Périodiques; Direct energy conversion; Periodicals; 621.3105
• DOI: 10.1016/j.enconman.2022.116195
• Languages: English
• ISSNs: 0196-8904

Abstract

Graphical abstract: Highlights: The co-digestion of FW and LL was feasible. Replacing 40% of the dilution liquid with LL yielded the optimum performance. LL addition alleviated the ammonia inhibition that the FW-based AD system suffered. The LL addition improved propionate, butyrate, and methane metabolism. Long-term use of leachate posed no ecological risk for digestate utilization. Abstract: To evaluate the feasibility of the co-digestion of food waste (FW) and landfill leachate (LL) to alleviate ammonia inhibition, a series of batch co-digestion experiments were conducted to explore the optimal substrate mixing ratio, and semi-continuous experiments were conducted to evaluate the long-tern effects of LL addition on methane generation and digestate characteristics of the anaerobic co-digestion system under ammonia stress. The optimum methane generation and digestate properties were observed when the concentration of LL in the dilution liquid in the co-digestion reactor was 40 % (v/v). Significant volatile fatty acid accumulation and lower methane yields were both observed during the long-term FW mono-digestion when the total ammonia nitrogen (TAN) concentration reached 3391.27 mg·L –1 . However, stable methane generation was observed in the co-digestion system, even when the TAN was 3721.59 mg·L –1, confirming that the LL alleviated the ammonia inhibition of the FW-based anaerobic digestion (AD) system. Microbial analysis of the AD reactors demonstrated that the relative abundance of Pelotomaculum was higher in the co-digestion system than in the mono-digestion system. Analysis of the phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) confirmed the enrichment of genes involved in butyrate, propionate, and methane metabolism in the co-digestion system. In addition, analysis of the digestate characteristics (i.e., dewaterability, germination index, and heavy metals concentrations) indicated that there was no ecological risk for utilization of the digestate after long-term co-digestion operation. These results aim to provide guidance for using LL to promote the processing of FW in the future.