Nitrification plays a key role in N2O emission in electric-field assisted aerobic composting

Jiahuan Tang; Xiang Li; Peng Cui; Jiayang Lin; Raymond Jianxiong Zeng; Hao Lin; Shungui Zhou

doi:10.1016/j.biortech.2019.122470

Nitrification plays a key role in N₂O emission in electric-field assisted aerobic composting

Bioresour Technol. 2020 Feb:297:122470. doi: 10.1016/j.biortech.2019.122470. Epub 2019 Nov 20.

Authors

Jiahuan Tang¹, Xiang Li¹, Peng Cui¹, Jiayang Lin¹, Raymond Jianxiong Zeng¹, Hao Lin², Shungui Zhou³

Affiliations

¹ Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China.
² School of Ecology and Resource Engineering, Wuyi University, Wuyishan City, Fujian 350002, China.
³ Fujian Provincial Key Laboratory of Soil Environmental Health and Regulation, College of Resources and Environment, Fujian Agriculture and Forestry University, Fuzhou 350002, China. Electronic address: sgzhou@soil.gd.cn.

PMID: 31791916
DOI: 10.1016/j.biortech.2019.122470

Abstract

Nitrous oxide (N₂O) emission is a serious environmental problem in composting. Previous studies have indicated that electric field assistance results in lower N₂O emissions in aerobic composting; however, the exact mechanisms involved in electric-field assisted aerobic composting (EAAC) are not clear. In this study, the biological N transformation processes and the N-associated genes were investigated. The results demonstrated that electric field application inhibited nitrification, weakened the nitrifying functional genes (the hao and nxrA genes declined maximally by 86% and 86.8%, respectively), and increased the N₂O consumption-related gene (nosZ) by a maximum factor of 2.76 compared with that in CAC. The correlation analysis demonstrated that nitrification was the main source of N₂O emission in EAAC. The findings imply that EAAC is a promising process for mitigating N₂O emission at the source during aerobic composting.

Keywords: Electric-field assisted aerobic composting; Functional genes; N(2)O emission; Nitrification.

MeSH terms

Composting*
Denitrification
Electricity
Nitrification*
Nitrous Oxide

Substances

Nitrous Oxide