Metal–organic framework-derived porous metal oxide/graphene nanocomposites as effective adsorbents for mitigating ammonia nitrogen inhibition in high concentration anaerobic digestion of rural organic waste. (15th January 2023)

• Record Type: Journal Article
• Authors: Jia, Zhaoyan; Ye, Xiaomei; Liu, Yang; Wang, Chengcheng; Cao, Chunhui; Du, Jing; Kong, Xiangping; Chen, Zhongbing; Xi, Yonglan
• Is Part Of: Fuel. Volume 332(2023)Part 1
• Publication Date: 2023-01-15
• Subjects: Anaerobic digestion -- Ammonia nitrogen inhibition -- Metal-organic frameworks -- Ammonia nitrogen adsorption; Fuel -- Periodicals; Coal -- Periodicals; Coal; Fuel; Periodicals; 662.6
• DOI: 10.1016/j.fuel.2022.126032
• Languages: English
• ISSNs: 0016-2361

Abstract

Graphical abstract: Highlights: FeMn-MOF/G were first applied in AD to mitigate ammonia nitrogen inhibition. FeMn-MOF/G could significantly increase methane production. FeMn-MOF/G can be recycled green by ordinary magnets. The adsorption capacity of regenerated FeMn-MOF/G is still 88.62% of the initial value. Abstract: Anaerobic digestion (AD) is an efficient technology that can efficiently convert organic waste into biofuel, but excessive ammonia nitrogen concentration will lead to failure of AD. In this study, a metal–organic framework (MOF)-derived porous metal oxide/graphene nanocomposite (FeMn-MOF/G) was first applied in AD to investigate the mitigation effect of ammonia nitrogen inhibition. Five total solids (TS) concentrations of 8 %, 10 %, 12 %, 15 % and 20 % were set up for AD experiment to investigate the effect of FeMn-MOF/G on AD. The results showed that the average ammonia nitrogen adsorption capacity of FeMn-MOF/G in AD with different TS concentrations was 102.68 mg/g, and the ammonia nitrogen adsorption effect decreased with the increase of TS. When FeMn-MOF/G was added to AD, the ammonia nitrogen concentration of the experimental group could be reduced to 2, 086.00 mg/L, and the VFAs concentration was reduced to 1, 510.34 mg/L. The methane production in each experimental group increased significantly, and the experimental group MOF-8 obtained the highest cumulative methane production of 321.35 mL/gVS, indicating that FeMn-MOF/G effectively mitigated the ammonia nitrogen inhibition, which promoteed the successful operation of AD. We characterized the prepared FeMn-MOF/G. The results of the vibrating sample magnetometer show that FeMn-MOF/G has excellent superparamagnetic properties. Magnetic recycling is a promising method for the recycling of FeMn-MOF/G materials, which provides a broad prospect for the application of FeMn-MOF/G in AD.