Cost solid waste

ACC Annualized capital costs MSW Municipal solid waste... 

Manual Component Separation The manual separation of solid-waste components can be accomplished at the source where solid wastes are generated, at a transfer station, at a centralized processing station, or at the disposal site. Manual sorting at the source of generation is the most positive way to achieve the recoveiy and reuse of materials. The number and types of components salvaged or sorted (e.g., cardboard and high-quality paper, metals, and wood) depend on the location, the opportunities for recycling, and the resale market. There has been an evolution in the solid waste indus-tiy to combine manual and automatic separation techniques to reduce overall costs and produce a cleaner product, especially for recyclable materials. 

Site Selection Factors that must be considered in evaluating potential solid-waste-disposal sites are summarized in Table 25-71. Final selection of a disposal site usually is based on the results of a preliminary site survey, results of engineering design and cost studies, and an environmental-impact assessment. 

The fuel value of most solid wastes is usually sufficient to enable self-supporting combustion, leaving only the incombustible residue and redlicing the volume of waste eventually consigned to sanitaiy landfills to only 10 to 15 percent of the original volume. The heat released by the combustion of waste can be recovered and utilized, although the cost of the recoveiy equipment or the distance to a suitable point of use for the heat may make its recoveiy economically infeasible. 

Economic evaluations of waste-reduction options should involve a comparison of operating costs to illustrate where cost savings would accrue. For example, a waste-reduction measure that reduces the amount of raw material lost down the drain during the process will reduce raw-material costs. Raw-material substitution or process changes may reduce the amount of solid waste that must be transported offsite, reducing the transport costs for waste disposal. 

Tier 0 and Tier 1 costs are direct and indirect costs. They include the engineering, materials, labor, construction, contingency, etc., as well as waste-collection and transportation services (in many cases we simply transform an air pollution problem into a solid waste or wastewater problem that requires final treatment and disposal), raw-material consumption (increase or decrease), and production costs. Tier 2 and... 

Semidry Scrubbers The advantage of semidry scrubbers is in that they remove contaminants by way of a solid waste that is easier to dispose of (less expensive). Initially, the scrubbing medium is wet (such as a lime or soda ash slurry). Then a spray dryer is used to atomize the slurry into the gas which evaporates the water in the droplets. As this takes place, the acid in the gas neutralizes the alkali material and forms a fine white solid. Most of the white solids are removed at the bottom of the scrubber while some are carried into the gas stream and have to be removed by a filter or electrostatic precipitator (discussed later). Although semidry systems cost 5-15% more than wet systems, when combined with a fabric filter, they can achieve 90-95% efficiencies. Dry scrubbers are sometimes used in a very similar fashion, but without the help of gas-liquid-solid mass transfer, these systems use much higher amounts of the solid alkali materials. 

A green chemistry variation makes use of solventless conditions to minimize the waste stream from reactions of this type. To a mortar are added aldehyde 67, ketone 68 and solid sodium hydroxide. The mixture is ground and within 5 minutes aldol product 69 is produced. Addition of the second ketone and further grinding affords the 1,5-diketone 70, which can be isolated and cyclized to pyridine 71 with ammonium acetate. The authors report that this method can substantially reduce the solid waste (by over 29 times) and is about 600% more cost effective than previously published procedures. 

A new scheme for location management has developed whereby wastes are diverted to separate holding facilities according to the hazard imposed by the waste. Separate pits are created to hold rig washing and precipitation wastes, solid wastes and drilling fluids [225]. The waste is then reused, disposed on site, or hauled away for offsite treatment. The system reduces contamination of less hazardous materials with the more hazardous materials, thereby reducing disposal costs. 

In addition to the solid waste problem, we can also expect that with expanding population or expanding demands of a static population, there will be societal pressure to reduce material usage over and above cost factors. These pressures could result in legislation to expand the environmental protection philosophy. For example, since plant materials are a renewable resource as well as readily recyclable, we may expect forced increases in paper-based packages. 

Process problems include slag formation, ash removal, and process control because of the heterogeneous solid waste feed. These problems have been managed to some degree by "overdesigning" the plant, with the result that combustion of municipal solid waste is not economically competitive in areas where low-cost electricity or landfills for waste disposal are available. The future cost of electricity is difficult to predict. However, the steady decrease in the availability of landfills portends increasing use of this process to dispose of municipal wastes, particularly in large cities. 

Processing Costs of Waste Materials in a Municipal Solid Waste Incinerator, Report TNO-MEP R96/248, TNO-MEP, Apeldoom, the Netherlands, 1996. 

Economical factors, such as disposal costs, the availability of conventional materials, and transportation costs, are critical considerations. As with any material, transportation costs are generally the highest cost factor in recycling solid waste. The most economically sustainable options for recycling foundry solid waste will generally match the volume and characteristics of the materials with nearby businesses and construction projects. Small foundries may not generate enough material on a weekly or monthly basis to satisfy the need for construction sands. In this case, it may be necessary to collect similar wastestreams from multiple sources or to partially substitute for conventional materials in order to meet volume requirements. 

Some end-use applications may prefer the characteristics of foundry solid waste. For instance, spent foundry sand is a uniformly graded fine aggregate containing chemically active iron and organics. Spent foundry sand can be superior to other types of granular materials, such as compacted soils or clays, for hydraulic barriers. In this case, spent foundry sand provides better performance at lower cost. 

It should be noted that early remedial actions for contaminated soil consisted primarily of excavation and removal of the contaminated soil from the site and its disposal at a landfill. SARA strongly recommends on-site treatment that permanently and significantly reduces the volume, toxicity, or mobility of hazardous substances, and utilizes cost-effective permanent solutions. The legislation prohibits land disposal of hazardous wastes unless U.S. EPA determines otherwise (as in the Hazardous and Solid Waste Amendments, HSWA). 

Source U.S. EPA, Steel Pickling, U.S. Environmental Protection Agency, Washington, DC, June 2008. Available at http // www.epa.gov/tri/TWebHelp/WebHelp/hcl section 3 l 4 steel pickling.htm a Included in annual waste management cost for miscellaneous solid waste. 

Utilize a trash compactor to reduce the volume of municipal trash shipped off-site, thereby reducing disposal costs. Miscellaneous solid waste 0a 0 12,810 15,000 1.2... 

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