TY - JOUR
T1 - Moisture relationships in composting processes
AU - Richard, Tom L.
AU - (Bert) Hamelers, H. V.M.
AU - Veeken, Adrie
AU - Silva, Tiago
N1 - Funding Information:
The authors appreciate the assistance of Sherry Baker, Zhi Zhang, Jodi Ohmacht, and Beth Bloom with experimental data collection. This study was partially supported by Bluestem Solid Waste Agency, the EET-program of the Dutch Ministery of Economic affairs, the Iowa State University Agricultural Experiment Station and the Iowa Biotechnology Byproducts Consortium.
PY - 2002
Y1 - 2002
N2 - Moisture is a key environmental factor that affects many aspects of the composting process. Biodegradation kinetics are affected by moisture through changes in oxygen diffusion, water potential and water activity, and microbial growth rates. These relationships are made more complex by the dynamic nature of the composting process, with changes in particle size and structure occurring over time. A deductive model of the effects of moisture on composting kinetics has defined these relationships based on fundamental physical properties and biological mechanisms. This study applies this model to experimental data from a manure and papermill sludge composting system. The results demonstrate that the optimum moisture content for biodegradation can vary widely for different compost mixtures and times in the composting process, ranging from near 50 to over 70% on a wet basis. While there is a significant reduction in biodegradation rate when operating outside the optimum range, the results also suggest opportunities to mitigate this effect through manipulation of substrate density and particle size. This framework for engineering analysis demonstrates the importance and challenges of maintaining optimum moisture content in dynamic composting systems, where biological drying, metabolic water production, and changes in compaction and porosity are all occurring over time.
AB - Moisture is a key environmental factor that affects many aspects of the composting process. Biodegradation kinetics are affected by moisture through changes in oxygen diffusion, water potential and water activity, and microbial growth rates. These relationships are made more complex by the dynamic nature of the composting process, with changes in particle size and structure occurring over time. A deductive model of the effects of moisture on composting kinetics has defined these relationships based on fundamental physical properties and biological mechanisms. This study applies this model to experimental data from a manure and papermill sludge composting system. The results demonstrate that the optimum moisture content for biodegradation can vary widely for different compost mixtures and times in the composting process, ranging from near 50 to over 70% on a wet basis. While there is a significant reduction in biodegradation rate when operating outside the optimum range, the results also suggest opportunities to mitigate this effect through manipulation of substrate density and particle size. This framework for engineering analysis demonstrates the importance and challenges of maintaining optimum moisture content in dynamic composting systems, where biological drying, metabolic water production, and changes in compaction and porosity are all occurring over time.
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U2 - 10.1080/1065657X.2002.10702093
DO - 10.1080/1065657X.2002.10702093
M3 - Article
AN - SCOPUS:0346949033
SN - 1065-657X
VL - 10
SP - 286
EP - 302
JO - Compost Science and Utilization
JF - Compost Science and Utilization
IS - 4
ER -