Submitted to: Scanning Microscopy
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: September 23, 1996
Publication Date: N/A
Interpretive Summary: Composting municipal solid waste(MSW) is becoming a popular method to deal with the immense problem of waste disposal currently facing society. If handled properly, composted MSW can convert trash into useful material for agricultural production. Direct evaluation of biological solid waste material(biosolids), clippings from turf and ornamental vegetation(yardwastes) and pine bark were performed using conventional light microscopy(CLM), scanning electron microscopic(SEM) and energy dispersive x-ray analysis(EDXA). Microscopic plastic film residues were identified using CLM, SEM and EDXA from composted MSW produced by a specific process that screened particles of 4mm or less in size although the latter appeared to be free of plastics when observed with the unaided eye. Plastic particles were not detected in sources from composted yardwastes and pine bark. The amount of plastic film residue and other potentially problem materials can be quantified with SEM and EDXA previously not available. Composition of composted wastes is significantly determined by source, waste separation and composting methods and equipment.
Technical Abstract: The relative quantity and composition of plastic films and other inerts in composts prepared from municipal solid wastes(MSW), biosolids, yardwastes, and pine bark were evaluated utilizing light and scanning microscopy equipped with energy dispersive X-ray analysis. MSW compost samples screened through a 4 mm screen contained significant but highly variable quantities of plastic film residues that escaped detection with the unaide eye. The other composts were free of such small particulate man-made inerts even though the raw products from which some were prepared contained plastic film. It was concluded that waste separation and the system of composting used significantly affected the quantity of plastic film residues recovered from composts.