Effects of sludge thermal hydrolysis pretreatment on anaerobic digestion and downstream processes: mechanism, challenges and solutions. (January 2022)

• Record Type: Journal Article
• Authors: Yan, Wangwang; Xu, Hui; Lu, Dan; Zhou, Yan
• Is Part Of: Bioresource technology. Volume 344:Part B(2022)
• Publication Date: 2022-01
• Subjects: Sludge pretreatment -- Thermal hydrolysis pretreatment -- Potential solutions -- Anaerobic digestion centrate -- Refractory compounds; 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.2021.126248
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Benefits and drawbacks of THP as sludge AD pretreatment are summarized. Solutions to tackle THP associated problems are proposed targeting each treatment step. Technology readiness of each solution is evaluated. In-situ AD enhancement using conductive materials and AOPs are promising solutions. Abstract: Thermal hydrolysis pretreatment (THP), as a step prior to sludge anaerobic digestion (AD), is widely applied due to its effectiveness in enhancing organic solids hydrolysis and subsequent biogas productivity. However, THP also induces a series of problems including formation of refractory compounds in THP cylinder, high residual ammonia and organic in the AD centrate, inhibition on downstream nitrogen removal process and reduction in UV-disinfection effectiveness during post-treatment. More attention should be paid on how to mitigate these negative effects. Despite intensive studies were carried out to reduce refractory compounds formation and enhance biological performance, there is limited effort to discuss the solutions to tackle the THP associated problems in a holistic manner. This paper summarizes the solutions developed to date and analyzes their technology readiness to assess application potential in full-scale settings. The content highlights the limitations of THP and proposes potential solutions to address the technological challenges.