Nitrogen evolution during membrane-covered aerobic composting: Interconversion between nitrogen forms and migration pathways

• Published in: Journal of environmental management Vol. 345; p. 118727
• Main Authors: Xiong, Jinpeng, Zhuo, Qianting, Su, Ya, Qu, Huiwen, He, Xueqin, Han, Lujia, Huang, Guangqun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2023
• Subjects: Interconversion pathways; Membrane-covered aerobic composting; Nitrogen balance; Nitrogen fractions; Nitrogen migration; Membrane-covered aerobic composting; Nitrogen fractions; Nitrogen balance; Nitrogen migration; Interconversion pathways
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2023.118727

Aerobic composting is a promising technology for converting manure into organic fertilizer with low capital investment and easy operation. However, the large nitrogen losses in conventional aerobic composting impede its development. Interconversion of nitrogen species was studied during membrane-covered aerobic composting (MCAC) and conventional aerobic composting, and solid-, liquid-, and gas-phase nitrogen migration pathways were identified by performing nitrogen balance measurements. During the thermophilic phase, nitrogenous organic matter degradation and therefore NH3 production were faster during MCAC than uncovered composting. However, the water films inside and outside the membrane decreased NH3 release by 13.92%–22.91%. The micro-positive pressure environment during MCAC decreased N2O production and emission by 20.35%–27.01%. Less leachate was produced and therefore less nitrogen and other pollutants were released during MCAC than uncovered composting. The nitrogen succession patterns during MCAC and uncovered composting were different and NH4+ storage in organic nitrogen fractions was better facilitated during MCAC than uncovered composting. Overall, MCAC decreased total nitrogen losses by 33.24%–50.07% and effectively decreased environmental pollution and increased the nitrogen content of the produced compost. [Display omitted] •Membrane-covered aerobic composting (MCAC) decreased total N loss by 33.24%–50.07%.•MCAC decreased N2O but increased NH3 production and emissions.•The water film in the MCAC system prevented 13.92%–22.91% of NH3 emissions.•MCAC promoted conversion of NH4+ into organic N and therefore decreased N losses.•MCAC significantly decreased leachate production during composting.