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Title: Coal-waste artificial-reef program: Conscience Bay studies

Technical Report ·
OSTI ID:6039823

Fly ash and different forms of flue-gas-desulfurization (FGD) waste (scrubber sludge, scrubber filtercake and fluidized-bed-combustion residue) were stabilized into blocks. In spring 1977 these blocks were submerged in Conscience Bay, Long Island Sound, an estuarine environment. The blocks were colonized by a diverse aquatic community of marine plants and animals almost immediately following submersion. Uptake of trace metals from the coal waste blocks by the epibenthic community was not greater than that found for organisms removed from concrete and natural rock reference blocks placed nearby. Boring bivalves and grazing snails were also examined for trace-metal enrichment; none was evident. By the end of the first year of submersion the different substrates supported a similar community. All but one formulation of stabilized block have maintained their structural integrity. Little physical abrasion or erosion was observed but biological erosion by the boring clam Zirfaea crispata was observed to occur. Compressive strength and surface hardness of the blocks were a function of the flue-gas-desulfurization waste used in block fabrication. All blocks experienced increased porosity following placement. Alteration in the mineralogical composition of stabilized blocks containing fluidized-bed-combustion residue following placement in the sea was the main reason for the blocks' structural deterioration. Following submersion, alterations in elemental composition suggest that these blocks may scavenge some trace metals from the marine environment. The leaching of calcium from the blocks was modelled in the laboratory and was not very different from in situ leaching. The results indicated that ocean disposal of stabilized blocks comprised of power plant coal wastes appear to be compatible with the marine environment.

Research Organization:
State Univ. of New York, Stony Brook (USA). Marine Sciences Research Center
OSTI ID:
6039823
Report Number(s):
EPRI-CS-3071; ON: DE83902347
Resource Relation:
Other Information: Portions are illegible in microfiche products
Country of Publication:
United States
Language:
English