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Wood waste containing formaldehyde based resins are generated yearly and disposed in landfills or burned. No regulations exist in most states and no studies have been conducted to address formaldehyde emission from wood waste buried in landfills. The objective of this study was to: a) determine the amount of formaldehyde released into air and leachate from MDF disposed in a simulated landfill, b) analyze the environmental impacts of leachate containing formaldehyde, and c) investigate change in chemical and morphological properties of disposed MDF. Sampling of MDF, soil and leachate were conducted for determination of formaldehyde weekly for 56 days by HPLC. Environmental impacts of leachate was determined by BOD, COD, and toxicity. Changes in the chemical composition and morphological structures were also determined. No detectable formaldehyde was observed in MDF, soil or leachate after 28 days. The BOD and COD levels indicated the leachate was not suitable for drinking.

High density polyethylene (HDPE) geomembranes are normally used as part of a composite liner for waste containment facilities such as municipal solid waste (MSW) landfills and heap leach pads. Field conditions, which include physical stresses on the geomembrane, elevated operating temperatures, and contact with leachate constituents, have the potential to affect the service life of the HDPE geomembranes. This thesis examined the long-term performance of different HDPE geomembranes based on both conventional laboratory accelerated immersion tests and simulated landfill liner tests. A 1.5mm HDPE geomembrane was immersed in different synthetic leachates at different temperatures in order to evaluate the effects of leachate chemical constituents on the depletion of antioxidants. The results showed that a basic leachate with trace metals, surfactant, and a reducing agent was the most appropriate for evaluating the potential degradation of HDPE geomembranes. A similar immersion test was performed to evaluate the effects of thickness on the ageing of HDPE geomembranes. Three commercially available HDPE geomembranes having nominal thicknesses of 1.5, 2.0, and 2.5mm were immersed in a synthetic leachate at four different temperatures in this experiment. The results showed that a thicker geomembrane may have a longer service life if other things are similar. The depletion of antioxidants from a 1.5mm thick HDPE geomembrane was examined by conducting accelerated ageing tests at 55, 70, and 85oC under simulated landfill liner conditions. The results showed that the antioxidant depletion rate was consistently lower for the simulated landfill liner tests compared to the leachate immersion tests. The effectiveness of the aged HDPE geomembrane on the migration of volatile organic compounds (VOCs) was examined by conducting diffusion and partitioning tests using both unaged and aged HDPE geomembranes. The results showed that the ageing of HDPE geomembranes did not increase diffusive migration of organic contaminants, provided that the geomembrane remained intact. A new method was developed to estimate the service life of the HDPE geomembrane based on the landfill liner temperature history. The service lives of the HDPE geomembranes were calculated to be between 20 and 4700 years, depending on the geomembrane type, exposure conditions, and the time-temperature history examined. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2009-01-30 09:30:49.135