title: Effects of aeration method and aeration rate on greenhouse gas emissions during composting of pig feces in pilot scale.
abstract: The aim of this study was to uncover ways to mitigate greenhouse gas (GHG) emissions and reduce energy consumption during the composting process. We assessed the effects of different aeration rates (0, 0.18, 0.36, and 0.54 L/(kg dry matter (dm)·min)) and methods (continuous and intermittent) on GHG emissions. Pig feces and corn stalks were mixed at a ratio of 7:1. The composting process lasted for 10 weeks, and the compost was turned approximately every 2 weeks. Results showed that both aeration rate and method significantly affected GHG emissions. Higher aeration rates increased NH3 and N2O losses, but reduced CH4 emissions. The exception is that the CH4 emission of the passive aeration treatment was lower than that of the low aeration rate treatment. Without forced aeration, the CH4 diffusion rates in the center of the piles were very low and part of the CH4 was oxidized in the surface layer. Intermittent aeration reduced NH3 and CH4 losses, but significantly increased N2O production during the maturing periods. Intermittent aeration increased the nitrification/denitrification alternation and thus enhanced the N2O production. Forced aeration treatments had higher GHG emission rates than the passive aeration treatment. Forced aeration accelerated the maturing process, but could not improve the quality of the end product. Compared with continuous aeration, intermittent aeration could increase the O2 supply efficiency and reduced the total GHG emission by 17.8%, and this reduction increased to 47.4% when composting was ended after 36 days.
authors.affiliation: College of Chemistry, Leshan Normal College, Leshan 614004, China; College of Resources and Environment Sciences, China Agricultural University, Beijing 100193, China. Electronic address: composting@163.com.
authors.forename: Tao
authors.initials: T
authors.lastname: Jiang
authors.affiliation: College of Resources and Environment Sciences, China Agricultural University, Beijing 100193, China. Electronic address: ligx@cau.edu.cn.
authors.forename: Guoxue
authors.initials: G
authors.lastname: Li
authors.affiliation: College of Chemistry, Leshan Normal College, Leshan 614004, China.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Tang
authors.affiliation: College of Chemistry, Leshan Normal College, Leshan 614004, China.
authors.forename: Xuguang
authors.initials: X
authors.lastname: Ma
authors.affiliation: College of Chemistry, Leshan Normal College, Leshan 614004, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.affiliation: Johann Heinrich von Thuenen-Institute, Institute of Agricultural Technology and Biosystems Engineering, Bundesallee 50, 38116 Braunschweig, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Schuchardt
mesh_terms: D000641:Ammonia / Q000737:chemistry; D000818:Animals; D005243:Feces / Q000737:chemistry*; D005740:Gases; D017752:Greenhouse Effect; D008697:Methane / Q000737:chemistry; D009609:Nitrous Oxide / Q000737:chemistry; D012037:Refuse Disposal / Q000379:methods*; D012987:Soil; D013552:Swine; D013696:Temperature
chemical_list: D005740:Gases; D012987:Soil; D000641:Ammonia; D009609:Nitrous Oxide; D008697:Methane
keywords: Composting; Forced aeration; Greenhouse gas; Intermittent aeration; Passive aeration