EVALUATING ONSITE BENEFICIAL REUSE OF GROUND ENGINEERED WOOD WASTES FROM RESIDENTIAL CONSTRUCTION

摘要

Wood wastes from residential construction can be potentially reused onsite as mulches. Engineered wood products (EWP) are estimated to comprise about 30% of residential construction wood waste. Due to the presence of various adhesives, there is concern about the beneficial reuse of these materials. We evaluated potential environmental impacts of mulches with a ground EWP component. No hazardous levels of constituents were found using a toxicity characteristic leaching procedure (TCLP). Changes in runoff water quality and soil chemistry below the mulch were evaluated through rainfall simulation on 0.9 × 4.6 m test plots using four treatments: bare soil control, 100% dimension lumber, typical residential mix of wood wastes, and 100% structural EWPs. A companion study evaluated the effect of the 100% EWP and the typical residential mix mulches on the growth of common landscaping plants. No purgeable halocarbons, benzene, toluene, ethyl benzene, xylene, or phenols were detected in runoff. Nutrient concentrations in runoff from the freshly ground wood treatments ranged from 0.5 to 8.19 mg L -1 for total nitrogen and 0.13 to 0.21 mg L -1 for total phosphorus. The freshly ground 100% EWP treatment had the highest total nitrogen concentrations in runoff (8.19 mg L -1 ). Biochemical oxygen demand was similar for all freshly ground wood treatments, ranging from 155 to 273 mg L -1 . These concentrations decreased by an order of magnitude after one year. There were no significant impacts on the growth of three common landscaping plants. Results indicate that these wood wastes can be beneficially reused rather than landfilled