A comparative study of single- and two-phase anaerobic digestion of food waste under uncontrolled pH conditions. (August 2018)

• Record Type: Journal Article
• Authors: Jo, Yeadam; Kim, Jaai; Hwang, Kwanghyun; Lee, Changsoo
• Is Part Of: Waste management. Volume 78(2018)
• Page Start: 509
• Page End: 520
• Publication Date: 2018-08
• Subjects: Anaerobic digestion -- Food waste -- Microbial community structure -- Two-phase system -- Uncontrolled pH operation; Hazardous wastes -- Periodicals; Refuse and refuse disposal -- Periodicals; 363.728
• DOI: 10.1016/j.wasman.2018.06.017
• Languages: English
• ISSNs: 0956-053X

Abstract

Highlights: Single- and two-phase AD systems were compared for FW treatment without pH control. Both systems required trace element supplementation at OLRs above 2.0 g VS/L∙d. Two-phase system showed higher methanation performance at OLRs up to 4.0 g VS/L∙d. Single-phase system is advantageous for stable and robust operation at higher OLRs. Hydrogenotrophic methanogens dominated the methanogen community in both systems. Abstract: This study compared single- versus two-phase systems for semi-continuous anaerobic digestion of food waste without pH control at varying organic loading rates (OLRs). The methanogenic reactors of both systems required trace element supplementation for stable operation at 3.0 g VS (volatile solids)/L∙d or higher OLRs. Under trace-element supplemented conditions, both systems achieved stable and efficient performance at OLRs up to 4.0 g VS/L∙d. The two-phase system outperformed the single-phase system at 1.0–4.0 g VS/L∙d OLRs, but it failed at an OLR of 5.0 g VS/L∙d. Meanwhile, the single-phase system maintained the stable performance and reached its maximum methane production at this OLR. These results suggest that a single-phase configuration is more advantageous for robust treatment of food waste without pH control at high organic and hydraulic loads. Hydrogenotrophic methanogens dominated the methanogen community throughout the experiment in both systems. Microbial community structure shifts correlated with reactor operation and performance characteristics.