Dry scrubber residues

Element Fresh bottom ash Ivsimeter extracted pore water and leachates (Chandler el al. 1997 Cranncll et al. 2000) Aged boiiuiit ash extracted pore waters (Mciina 1997) Dry and semi-dry scrubber residues low LS (0.0-0.2) column leachates (Chandler et al. 1997) Wet scrubber residue low LS 10.0-0.2) column leachates (Chandler et al. 1997)... 

Table 7. Identified phosphate mineral reaction products in phosphate-stabilized AfS lV dry scrubber residues... 

Ecke, H., Menad, N. Lagerkvist, A. 2002. Treatment-oriented characterization of dry scrubber residue from municipal solid waste incineration. Journal of Material Cycles Waste Management, 4, 117-126. 

Eighmy, T. T., Crannell, B. S. et al. 1997. Heavy metal stabilization in municipal solid waste combustion dry scrubber residue using soluble phosphate. Environmental Science Technology, 31, 3330-3338. 

The facility would use a dry scrubber system for emission control, which would eliminate the need for wastewater treatment. Any water from emission control and from decontamination procedures would be treated in the on-site groundwater treatment system. The residual soil and collected ash is assumed to be nonhazardous and can be disposed of in a solid waste disposal facility in compliance with subtitle D of RCRA. In the event that they cannot be delisted due to the presence of metals, the residuals will be managed as part of the closure of Area 2 shown in Figure 16.21 (lead-contaminated soil). 

During MSW combustion in a modern mass burn combustor with reciprocating grates, 11 of MSW is converted to heat gases such as C02, NOx, SOx, and H20 and about 350 kg of ash residuals partitioned into the various ash streams. For every tonne of MSW combusted, about 5 kg of grate siftings, 295 kg of grate ash, 5 kg of boiler/economizer ash, 20 kg of ESP ash, and 12 kg of dry scrubber solids are produced (Chandler et al. 1997). 

The bottom ash was treated with 0.4 moles of PO (from industrial-grade phosphoric acid) per kg dry weight of ash. The scrubber residue was treated with 1.2 moles of PO per kg of scrubber residue. The vitrification dust was treated with 0.4 moles of PO3- per kg of residue. Process mixing in all cases used an LS of 0.4. Mixing was done for 10 minutes in a Hobart mixer using a tined paddle (108 rpm) with a planetary orbit (48 rpm). 

The operation of both the dry and wet off-gas treatment systems generates secondary radioactive wastes. These typically include filters and filtrafitm materials, adsorption materials, and in the case of wet scrubbers, liquid scrub solutions and blowdowns. Dry scrubbers would produce secondary wastes in the form of solid neutralizing agents and their residues, probably mixed with fly ash. Some of these secondary wastes (both solid and liquid) may be processed by incineration or drying in the same incineration system. Others need to be handled by a separate volume reduction system or disposed of with or without immobilization. The ash removed from the various collection points in the off-gas treatment system also needs to be treated and disposed of with the bulk of the ash collected from the combustion system. 

DISPOSAL AND STORAGE METHODS absorb in dry earth or sand, package in epoxy-lined drums, and dispose of in a sanitary landfill atomize in a high-temperature incinerator, equipped with afterburner or hydrochloric acid scrubber encapsulate product residues by organic polyester resin or silicate fixation store in a cool, dry location storage should be in tightly closed containers separate from oxidizing materials, ammonia, and active metals isolate from open flames and combustibles. 

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