| This research generates analytical criteria for the utilization of Northern California yard-waste composts, regardless of the sample's feedstock, treatment facility, or final form. Several uniform methods are evaluated, including elemental, thermal, and infrared analysis. Findings show that compost quality, stability, and nitrogen release properties can be estimated, especially through van Krevelen elemental composition plots and by a thermo-gravimetric stability index. Relative increases of aromatic composition and decreased aliphatic composition are shown as a result of composting, especially with regard to compost size fraction. Likewise, relative nitrogen to carbon content is shown to increase with composting, especially with regard to compost size fraction. The correlation between increased thermal stability and nitrogen content is statistically significant for yard-waste compost. An infrared partial least squares prediction model is generated to predict values of the evaluated methods. Each of the methods are relatively cost-effective and time-efficient approaches that promote the increased use of yard-waste composted materials for erosion control and soil restoration to the mutual benefit of the landfill waste stream reduction effort. |
