Effect of initial bulk density on high-solids anaerobic digestion of MSW: General mechanism. (June 2017)

• Record Type: Journal Article
• Authors: Caicedo, Luis M.; Wang, Hongtao; Lu, Wenjing; De Clercq, Djavan; Liu, Yanjun; Xu, Sai; Ni, Zhe
• Is Part Of: Bioresource technology. Volume 233(2017)
• Page Start: 332
• Page End: 341
• Publication Date: 2017-06
• Subjects: Anaerobic digestion -- Initial bulk density -- Saturation -- Cumulative methane generation -- Mechanism; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2017.02.107
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Initial bulk density (IBD) may inhibit methane generation when it is >1000 kg m −3 . IBD had the largest impact on anaerobic digestion (AD) within the first 30 days. IBD defined the saturation level in the solid bed. IBD may impact the extraction of nutrients and the microbial community. A general mechanism was proposed, connecting IBD with the main variables in AD. Abstract: Initial bulk density (IBD) is an important variable in anaerobic digestion since it defines and optimizes the treatment capacity of a system. This study reveals the mechanism on how IBD might affect anaerobic digestion of waste. Four different IBD values: D1 (500–700 kg m −3 ), D2 (900–1000 kg m −3 ), D3 (1100–1200 kg m −3 ) and D4 (1200–1400 kg m −3 ) were set and tested over a period of 90 days in simulated landfill reactors. The main variables affected by the IBD are the methane generation, saturation degree, extraction of organic matter, and the total population of methanogens. The study identified that IBD >1000 kg m −3 may have significant effect on methane generation, either prolonging the lag time or completely inhibiting the process. This study provides a new understanding of the anaerobic digestion process in saturated high-solids systems.