Composting Residuals From a Strawboard Manufacturing Facility

Compost Science & Utilization, (2005), Vol. 13, No. 2, 90-97

Scott Chapman (1) and Daryl McCartney (2)

1. Department of Civil Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
2. Department of Civil and Environmental Engineering, University of Alberta, Edmonton, Alberta, Canada

The purpose of this research was to investigate the compostability of waste residuals from a strawboard manufacturing facility. Phase 1 used bench-scale reactors to compost various recipes using three feedstock materials (straw, process unders, and livestock lagoon sludge) at different moisture levels for a nine-week period. Water addition and the addition of unders to the compost mixture increased degradability. The livestock lagoon waste did not significantly improve degradability. Phase 2 focused on the straw feedstock, investigating the effects of straw particle size using four unshredded:shredded straw ratios (by volume): 100:0; 67:33; 33:67; and 0:100. The recipes were composted in 140 L rigid plastic containers for a period of 180 days at a moisture content of 70% (wet basis). Volatile solids (VS) and lignocellulose degradation was greatest for recipes containing both shredded and unshredded straw, with the recipe containing 67% shredded straw performing the best (35% VS removal). Pure unshredded and shredded straw had VS reductions of 29% and 26%, respectively. Total volume reductions ranged from 80 to 90%. Hemicellulose was completely degraded for all recipes by day 95. By day 180 cellulose content had decreased from 3.75 to 0.75 g/g ash for all four recipes. By day 180, lignin degradation was greatest for recipes containing both shredded and unshredded straw (reduction from 1.0 to 0.4 g/g ash) while lignin content decreased from 1.0 to 0.6 g/g ash for the other recipes. It was concluded that recipes containing a mixture of shredded and unshredded straw provided better composting conditions.

Copyright 2007, The JG Press, Inc.