Effect of sawdust addition on composting of separated raw and anaerobically digested pig manure
Troy, Shane M.
Leahy, James J.
Healy, Mark G.
MetadataShow full item record
This item's downloads: 507 (view details)
Troy, S.M., Nolan, T., Kwapinski, W., Leahy, J.J., Healy, M.G., Lawlor, P. (2012) 'Effect of sawdust addition on composting of separated raw and anaerobically digested pig manure'. Journal Of Environmental Management, 111 :70-77.
Manures need the addition of carbon-rich bulking agents to conserve N during composting, which increases the cost of the composting process. The recommended proportion of manure / sawdust, based on a carbon (C): nitrogen (N) ratio, is approximately 3:2. Two composting experiments were conducted to determine the impact of varying the proportion of sawdust to either separated raw, or separated anaerobically digested pig manures. To determine stability and maturity of the final compost, oxygen uptake rate (OUR) and germination index (GI) tests were conducted. For both experiments, three treatments were employed: manure-only (Treatment A), manure / sawdust mixed 4:1, fresh weight (Treatment B), and manure / sawdust mixed 3:2, fresh weight (Treatment C). The mixtures were composted in tumblers for 56 d with regular turning. The composting material was tested over the study duration for temperature, pH, water content, organic matter, C:N ratio and bulk density. For both Treatments B and C, the GI indicated low levels of phytotoxicity, and OUR values were lower than the recommended Irish threshold of 13 mmol O2 kg OM-1h-1, indicating that a high quality compost was produced. The proportion of sawdust to separated manure used can be reduced to make a cost saving, while still producing a stable end-product: 60 % less sawdust is required to compost at a manure-to-sawdust ratio of 4:1 compared to the previously recommended ratio of 3:2.
This item is available under the Attribution-NonCommercial-NoDerivs 3.0 Ireland. No item may be reproduced for commercial purposes. Please refer to the publisher's URL where this is made available, or to notes contained in the item itself. Other terms may apply.
The following license files are associated with this item: