Fe/BC co-conditioners with environmental and economic benefits on composting: reduced NH3 emissions and improved fertilizer quality
Jixiang Wang,
Huifang Xie,
Jun Wu,
Weijiang He,
Xi Zhang,
Junxia Huang,
Yanfang Feng,
Lihong Xue
Affiliations
Jixiang Wang
Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences
Huifang Xie
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology
Jun Wu
Key Laboratory of Integrated Regulation and Resources Development of Shallow Lakes, Ministry of Education, College of Environment, Hohai University
Weijiang He
Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences
Xi Zhang
Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences
Junxia Huang
Jiangsu Key Laboratory of Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology
Yanfang Feng
Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences
Lihong Xue
Key Laboratory of Agro-Environment in Downstream of Yangtze Plain, Ministry of Agriculture and Rural Affairs, Institute of Agricultural Resources and Environment, Jiangsu Academy of Agricultural Sciences
Abstract The significant volatilization of NH3 during aerobic composting causes nitrogen (N) losses and environmental risks. Both iron (Fe) and biochar (BC) can influence the N conversion process in composting. Fe application can delay the maturation of materials, while biochar can enhance the quality of organic fertilizer. The combination of these two conditioners may help decrease NH3 emissions and improve organic fertilizer quality. Therefore, this study investigates the effects of different doses of FeCl3 and BC on NH3 emissions and organic fertilizer quality during composting. The results demonstrated that Fe/BC co-conditioners reduced the accumulation of NH3 emissions during composting by 11.1–48.2%, increased the total nutrient content by 0.6–15.3%, and enhanced economic and environmental benefits by 0.1–23.6 $ t−1. At the high-temperature stage of composting, Fe/BC co-conditioners decreased the pH by 0.3–1.2, but there was no significant difference compared to the control at the end of composting, and they did not affect compost maturation. The structural equation model analysis suggested that the reduction in NH3 emissions was related to ammonia-oxidizing bacteria (AOB), NH4 +–N, and total nitrogen (TN). As a result, the Fe/BC co-conditioners reduced NH3 emissions by lowering the pH at the beginning of composting and increasing the content of NH4 +–N. This study concludes that Fe/BC co-conditioners could complement each other to significantly reduce NH3 emissions and improve the quality of organic fertilizers. Graphical Abstract
