Abstract
There is little information about the changes in physical and chemical properties of compost as a function of compost feedstocks and age of the compost mixture. As a consequence of this gap, the potential of compost to serve as a pollutant source relative to compost age (from initial mixing of raw feedstocks to mature compost) and feedstocks (i.e. % of food, manure, bedding, leaves, etc.) during the composting operation is not well known. This study was conducted to assess the variation of physical and chemical properties of compost under different mixes of source material and at differing ages (from freshly mixed to mature compost). The change in compost C:N ratio with age during composting was represented well (R2 ≥ 0.81) by the equation Y = CNf + (CNi-CNf)e(−X/r), where Y is the C:N ratio at any time X. CNf is the value of the C:N ratio as the composting time approaches infinity. CNi is the initial C:N ratio at the beginning of the composting process and 1/r is the rate of decrease of the C:N ratio. The total (tot) N concentration of the mature composts was higher than the initial tot N concentration for all mixes investigated. There was a net decrease from the initial NH4-N concentrations at mixing to the final NH4-N concentrations at maturity for all compost mixtures. However, the variations of compost tot N and NH44-N concentrations with compost age were different between compost mixtures and years of experiment. The phosphorus (P) concentrations increased linearly with compost age. These results indicated that the potential of the compost as a source for N and P pollution changes during the composting process. The results also showed that the combination of C:N ratio, compost temperature, and compost NH4-N concentration could be used as simple but reliable indices for compost stability and maturity.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 228-238 |
| Number of pages | 11 |
| Journal | Compost Science and Utilization |
| Volume | 16 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jan 1 2008 |
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All Science Journal Classification (ASJC) codes
- Ecology
- Waste Management and Disposal
- Soil Science
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Potential Pollutants from Farm, Food and Yard Waste Composts at Differing Ages : Part I. Physical and Chemical Properties. / Confesor, R. B.; Hamlett, J. M.; Shannon, Robert David; Graves, R. E.
In: Compost Science and Utilization, Vol. 16, No. 4, 01.01.2008, p. 228-238.Research output: Contribution to journal › Article
TY - JOUR
T1 - Potential Pollutants from Farm, Food and Yard Waste Composts at Differing Ages
T2 - Part I. Physical and Chemical Properties
AU - Confesor, R. B.
AU - Hamlett, J. M.
AU - Shannon, Robert David
AU - Graves, R. E.
PY - 2008/1/1
Y1 - 2008/1/1
N2 - There is little information about the changes in physical and chemical properties of compost as a function of compost feedstocks and age of the compost mixture. As a consequence of this gap, the potential of compost to serve as a pollutant source relative to compost age (from initial mixing of raw feedstocks to mature compost) and feedstocks (i.e. % of food, manure, bedding, leaves, etc.) during the composting operation is not well known. This study was conducted to assess the variation of physical and chemical properties of compost under different mixes of source material and at differing ages (from freshly mixed to mature compost). The change in compost C:N ratio with age during composting was represented well (R2 ≥ 0.81) by the equation Y = CNf + (CNi-CNf)e(−X/r), where Y is the C:N ratio at any time X. CNf is the value of the C:N ratio as the composting time approaches infinity. CNi is the initial C:N ratio at the beginning of the composting process and 1/r is the rate of decrease of the C:N ratio. The total (tot) N concentration of the mature composts was higher than the initial tot N concentration for all mixes investigated. There was a net decrease from the initial NH4-N concentrations at mixing to the final NH4-N concentrations at maturity for all compost mixtures. However, the variations of compost tot N and NH44-N concentrations with compost age were different between compost mixtures and years of experiment. The phosphorus (P) concentrations increased linearly with compost age. These results indicated that the potential of the compost as a source for N and P pollution changes during the composting process. The results also showed that the combination of C:N ratio, compost temperature, and compost NH4-N concentration could be used as simple but reliable indices for compost stability and maturity.
AB - There is little information about the changes in physical and chemical properties of compost as a function of compost feedstocks and age of the compost mixture. As a consequence of this gap, the potential of compost to serve as a pollutant source relative to compost age (from initial mixing of raw feedstocks to mature compost) and feedstocks (i.e. % of food, manure, bedding, leaves, etc.) during the composting operation is not well known. This study was conducted to assess the variation of physical and chemical properties of compost under different mixes of source material and at differing ages (from freshly mixed to mature compost). The change in compost C:N ratio with age during composting was represented well (R2 ≥ 0.81) by the equation Y = CNf + (CNi-CNf)e(−X/r), where Y is the C:N ratio at any time X. CNf is the value of the C:N ratio as the composting time approaches infinity. CNi is the initial C:N ratio at the beginning of the composting process and 1/r is the rate of decrease of the C:N ratio. The total (tot) N concentration of the mature composts was higher than the initial tot N concentration for all mixes investigated. There was a net decrease from the initial NH4-N concentrations at mixing to the final NH4-N concentrations at maturity for all compost mixtures. However, the variations of compost tot N and NH44-N concentrations with compost age were different between compost mixtures and years of experiment. The phosphorus (P) concentrations increased linearly with compost age. These results indicated that the potential of the compost as a source for N and P pollution changes during the composting process. The results also showed that the combination of C:N ratio, compost temperature, and compost NH4-N concentration could be used as simple but reliable indices for compost stability and maturity.
UR - http://www.scopus.com/inward/record.url?scp=59649084425&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=59649084425&partnerID=8YFLogxK
U2 - 10.1080/1065657X.2008.10702384
DO - 10.1080/1065657X.2008.10702384
M3 - Article
AN - SCOPUS:59649084425
VL - 16
SP - 228
EP - 238
JO - Compost Science and Utilization
JF - Compost Science and Utilization
SN - 1065-657X
IS - 4
ER -