Iron-based biochar derived from waste-activated sludge enhances anaerobic digestion of synthetic salty organic wastewater for methane production. (February 2022)

• Record Type: Journal Article
• Authors: Che, Linxuan; Yang, Bo; Tian, Qing; Xu, Hui
• Is Part Of: Bioresource technology. Volume 345(2022)
• Publication Date: 2022-02
• Subjects: Iron-rich sludge -- Iron-based biochar -- Anaerobic digestion -- Salty wastewater -- Methane production; 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.2021.126465
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Iron-rich waste-activated sludge is converted into iron-based biochar. Iron-based biochar boosts anaerobic treatment of saline wastewater. Optimal pyrolysis temperature for synthesizing iron-based biochar is 700℃. Fe3 O4 and ZVI on biochar are responsible for increased methane production. Undesirable inert Fe3 P is formed on biochar at a pyrolysis temperature of 800℃. Abstract: Herein, synthetic iron-based biochar was used in anaerobic digestion of synthetic salty organic wastewater for methane production. The iron-based biochar synthesized at different pyrolysis temperatures improved methane production. An optimal methane production of 551 ± 4.0 mL/L was achieved by adding iron-based biochar prepared at 700℃. The rate of hydrolysis-acidification and methanogenesis was promoted by iron-based biochar as the NaCl concentration was less than 20 g/L. However, the catalytic effect of iron-based biochar on methane production of saline wastewater failed during the NaCl concentration of 40 g/L due to the complete suppression of methanogenesis. Analyzing the methanogenic activity of iron-based biochar modified anerobic systems and characterizing the physical-chemical properties of iron-based biochar demonstrated that the iron oxides and/or zero-valent iron generated on the biochar surface increased methane production. This study highlights the potential benefits of iron-rich sludge-based biochar on enhanced anaerobic digestion and treatment of salty organic wastewater.