Twenty percent of all the material delivered to construction and demolition (C&D) disposal sites in the Province of Nova Scotia, Canada, is waste gypsum wallboard (WGW) (Dillon Consulting Ltd., 2006). This is typically in the form of residential or business demolition waste, which includes WGW from new construction activities. This study looked at the use of papered and de-papered waste gypsum wallboard in compost to evaluate its impact on the process, total heavy metal concentration, bioavailable metal concentration, and movement of heavy metals. The study consisted of three components: a short term mechanical in-vessel compost sub-study to assess the impact of composting WGW; a lysimeter cell sub-study to evaluate potential movement of compost constituents from compost to soil and water under a static compost system open to the ambient environmental conditions; and, a final sub-study to determine the performance of waste gypsum wallboard in compost under controlled composting conditions. The study found that the inclusion of up to 34% (by mass) WGW had no negative effects on the degradation of carbon, final pH, and final electrical conductivity in the compost product, however, WGW-containing composts did increase concentrations of total sulphur. There was the potential for elevated levels of total lead and cadmium but the compost produced was within the CCME Class A guidelines for heavy metal concentration. Waste gypsum wallboard containing composts also had increased levels of bioavailable cadmium compared to non-WGW composts.

No description available.

An experimental laboratory study was undertaken to investigate the convective airflow which develops in compost masses and the effect of passive and active aeration on nitrogen (N) and carbon (C) losses of compost at three different levels of dry matter (d.m) with four different C sources (pine shavings, grass hay, oat straw and wheat straw). Each bulking agent was individually mixed with swine slurry and composted at 40, 32 and 28% d.m. Duplicate mixtures were aerated for 21 days (14 days for one of the pine shavings trials) both in active and passive conditions in 100L composters and their temperature was monitored every 3 hours. The passively aerated compost demonstrated temperature regimes similar to that of the actively aerated compost reaching and exceeding 55°C for 3 days. The initial airflow resistance of the composts was found to be lower than the final. The convective airflow of the compost was correlated with time and to the difference in ambient and compost temperature. The 32% d.m. content and the wood shavings compost produced higher convective airflows. The statistical significance of the effects of aeration method, d.m. level, and C source on N conservation was tested. Only the C source had a significant effect (P < 0.05). The hay amended with urea had the lowest N losses (22.4%), followed by oat straw, hay, wood shavings amended with soybeans, wheat straw and wood shavings with losses of 41.4, 53.4, 53.6, 55.2% and 68.5% respectively. The C losses were strongly related to the N losses, except for the hay amended with urea compost. The oat straw loss the most C (51.4%), followed by hay, wheat straw, wood shavings amended with and without soybeans, and hay amended with urea with losses of 37.4, 35.8, 25.4%, 13.5% and 12.19% respectively. (Abstract shortened by UMI.)

No description available.

No description available.

Thesis--Auburn University, 2008. / Abstract. Vita. Includes bibliographical references (p. 92-97).

Thesis (Ph. D.) -- Lincoln University, 2008. / Also available via the World Wide Web.

Thesis (M.S.)--University of North Texas, Dec., 2009. / Title from title page display. Includes bibliographical references.

Thesis (M.S.) in Resource Ecomonics and Policy--University of Maine, 2003. / Includes vita. Includes bibliographical references (leaves 110-114).

Thesis (M. Phil.)--University of Hong Kong, 1996. / Includes bibliographical references (leaf 121-132).