Search

The search for a truly degradable synthetic polymer has led to the creation of the Advisory Committee on Degradable Polymers at the American Institute for Testing and Materials/Institute for Standards Research. The committee oversees the testing of these synthetic polymers on three levels. The first level is on screening, the second, on the first level of confirmation and the third, on the second level of confirmation. The results of a field study on the biodegradability of 11 synthetic polymers are presented.

Modified on-site composting of organics or food residuals may prove to be a cost-effective, long-term management decision for some institutions. Organic composting can achieve the 65% solid waste diversion by 2000 goal in Washington state. A pilot project at the Echo Glen Children's Center in Washington demonstrates the beneficial cost analysis of the composting program. Less frequent refuse collection, inclusion of biosolids composting and increase in product volume can make the program more cost-effective. The composting system at the center is described.

Cedar Grove, a division of the Northwest Waste Industries, is concentrating on overcoming the challenges and the operational modifications required for the expansion of its composting and recycling operations in Seattle and King County, Washington. The challenges faced include handling large volumes of yard trimmings, increasing the capacity of recycling, and controlling surface water runoff and off-site odor. A large static pile maximizes the processing area, reduces costs and decreases odor generation. Changes in the recycling processes and in marketing strategies are also discussed.

The end products of two different technologies for the processing of waste including food items, bottles, cans and plastic bags, the aerated static pile (ASP) and aerated turned windrow (ATW), are compared. The ATW composts have lesser density, more moisture holding capacity and low particle size, and the nutritional levels varied with the type of material used. In the ASP piles, the nutritional contents are not affected, probably due to the insulative cover, but the products obtained have physical characteristics that are not very good.

Clear Washington Center started a new pilot project to combat problems of recycling organic compostable grocery waste using low technology. The segregation of waste into disposable and non-disposable categories make the process easier. The pilot study indicates that wax-coated cardboards are easily destroyed.