Monitoring of Biochemical Parameters and GHG Emissions in Bioaugmented Manure Composting

• Main Author: Cevat Yaman
• Format: Article
• Language: English
• Published: MDPI AG 2020-06-01
• Series: Processes
• Subjects: bioaugmentation; manure; C:N ratio; windrow composting; greenhouse gas (GHG), agronomic testing
• Online Access: https://www.mdpi.com/2227-9717/8/6/681

Composting is a sustainable alternative for the management of manure. In this study, the effects of bioaugmentation on cattle manure composting was investigated. In this study, two windrow piles were placed at 1.7 m in height, 2.1 m in bottom width, 0.6 m in top width, and 54 m in length. Microbial inoculum was added to pile 1, whereas the second pile was used as the control. After 17 days, the C:N ratio was reduced from 25.6 to 13.6 and the total nitrogen was increased from 1.89% to 3.36% in pile 1. The dominant bacteria identified in the compost samples belonged to the genera <i>Clostridium</i>, <i>Bacillus</i>, and <i>Flavobacterium</i>. Quantitative polymerase chain reaction indicated that the most commonly known pathogenic bacteria, <i>Escherichia coli, Shigella,</i> and <i>Salmonella</i>, were not detected in the finished material, indicating that the pathogenic microorganisms were inactivated by the composting process. Agronomic testing for cured compost indicated a C:N ratio of less than 15 and NH⁺₄-N:NO₃⁻-N ratio of less than 1. The whole process of windrow composting resulted in net greenhouse gas (GHG) emissions of 157.94 tCO₂-e and a global warming factor (GWF) of 1.04 tCO₂-e·t⁻¹ manure composted. This study showed that although bioaugmentation is a feasible treatment method for manure, GHG emissions need to be monitored.