Mechanism and control strategy of ammonia and nitrous oxide during composting of municipal solid wastes

Chen Yi-Xiao,Pan Jia-Jing,Mo Jin-Tao,Lu Yi-Ming,Zhang Jun,T Zhu,M Anpo,A Sharifi

doi:10.1051/e3sconf/202127102003

Abstract

Aerobic composting is an effective way to realize recycling of organic solid wastes. It is not only convenient for operation and management, but also can convert waste into organic fertilizer. However during the composting process, the nitrogen in the heap exists in the form of organic nitrogen, ammonium nitrogen, nitrate nitrogen and other forms and is transformed into each other. It is also a potential source of ammonia (NH3) and nitrous oxide (N2O), and it is closely related to the environmental problems such as haze pollution and greenhouse effect. Combining with the researches of domestic and foreign scholars, this paper summarizes the form transformation of nitrogen elements, the emission mechanism of NH3 and N2O, and the adjustment and control measures in the aerobic composting process of the organic solid wastes, and it prospects the research direction for aerobic composting of the organic solid wastes.

Highlights

In recent years, most of the organic solid wastes are randomly discarded or discharged into the environment, causing great negative impacts on the ecological environment
Aerobic composting is an effective way for minimization, hazard-free treatment and resourceful disposal of the organic solid wastes such as municipal sludge, kitchen wastes and livestock excrements
When the relative humidity is high, it can react with H2SO4, HNO3 and HCl in the atmosphere to generate the secondary particles of ammonium salt, which is an important part of PM2.5 it can cause haze pollution to reduce the quality of the atmospheric environment, and it threatens the human health [3]

Summary

Introduction

Most of the organic solid wastes are randomly discarded or discharged into the environment, causing great negative impacts on the ecological environment. Municipal sludge is waste generated in the process of sewage treatment. Kitchen waste is easy to decay and deteriorate, and it is easy to breed bacteria. If placed improperly, it will have adverse effects on the social environment and human health. Aerobic composting is an effective way for minimization, hazard-free treatment and resourceful disposal of the organic solid wastes such as municipal sludge, kitchen wastes and livestock excrements. When the relative humidity is high, it can react with H2SO4, HNO3 and HCl in the atmosphere to generate the secondary particles of ammonium salt, which is an important part of PM2.5 it can cause haze pollution to reduce the quality of the atmospheric environment, and it threatens the human health [3]. If the composting process is not properly controlled, the emitted NH3 and N2O will affect the global

The form transformation of nitrogen elements during composting

The emission mechanism of NH3 and N2O during composting

The reduction measures of NH3 and N2O during composting

Findings

Conclusions