Materials handling strategies

Army Environmental Center (USAEQ recently completed a demonstration of windrow composting of explosives-contaminated sods at Umatilla Depot Activity (UMDA) in Hermiston, Oregon. This demonstration represented the second phase of field studies conducted at UMDA, and was part of an ongoing effort to develop a composting system which can provide an economical and effective alternative to incineration for the treatment of explosives-contaminated soils and sediments. 

In general, estimates of final compost volumes have been based upon rough assumptions, and in some cases, these volumes have been greatly overestimated. The purpose of this study was to present a preliminary estimation of the final compacted volume of treated compost to be backfilled at UMDA following full-scale remediation of the washout lagoons soils. The calculations have been based on a combination of field observations, laboratory analyses, and theoretical calculations. Ultimately, the final compost volume was presented in terms of the initial in-place volume of explosives-contaminated soils to be excavated from the washout lagoons site at UMDA. 

Once the compost mixture has been blended and formed into windrows, the volume of material will gradually decrease over time for a variety of reasons. Part of this volume decrease is due solely to the pulverization of the compost material by the windrow turner which results in smaller particle size and less pore space in the compost pile. In addition, a substantial portion of the organic matter will be respired by microorganisms to carbon dioxide and water which will then escape from the 

Finally, this finished compost material must be backfilled into the original excavation. Provided that the material is carefully replaced and compacted in thin lifts, a substantial reduction in the volume of the compost may be attainable. The extent of the compaction and volume reduction can be estimated by standard laboratory compaction tests conducted on representative samples of compost. Knowing this final compacted compost volume in terms of the original in-place soil volume is necessary to determine whether substantial excess compost will be created by the composting process, and whether backfilling the excavation and mounding this excess compost will be feasible for the site in question. 

The studies indicate that for every cubic yard of in-place soils which are excavated, a backfilled volume of up to 1.6 cubic yards will be created. Under the current proposed remediation at the washout lagoons, 3,900 yards of in-place soil would be excavated, which according to these calculations, will result in about 6,200 cubic yards of backfilled material. This material will be backfilled into the original excavation (3,900 cubic yards), and also into the existing lagoons which have a volume of about 1,200 cubic yards. This leaves a total of 1,100 cubic yards which will need to be mounded above the ground surface. If spread evenly over the surface of the site, this mound would be only 1.7 ft deep. Of course to promote runoff, the excess material may have to be mounded higher in the center and less around the perimeter. 

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Sample handling strategies for the determination of plant phenols in food and plant material have been reviewed [42]. Attention was paid to hydrolysis, liquid extraction, solid-phase extraction (SPE), and supercritical-fluid extraction. 

Thus, the basic design strategy for storing and handling hazardous materials can be summarized as follows, with reference to other parts of this section in parentheses ... 

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