Final disposal, solid waste

Under RCRA, waste producers are required to take a cradle to grave approach to waste management. The producer of the waste is legally liable from the moment that waste is produced until its final disposal. A waste generator must identify waste material as hazardous waste if it is on a regulatory list or has a characteristic of flammability, toxicity, corrosivity, or reactivity. Once a material has been identified as hazardous waste, it must be clearly labeled and tracked when in transport. The waste must be treated in special facilities to low levels of contaminants. The final residual solid material, for example, incinerator ash, must be disposed into a registered hazardous waste landfill. 

Functional Elements The activities associated with the management of solid wastes from the point of generation to final disposal have been grouped into the functional elements identified in Fig. 25-59. By considering each fundamental element separately, it is possible to (1) identify the fundamental element and (2) develop, when possible, quantifiable relationships for the purpose of making engineering comparisons, analyses, and evaluations. 

Disposal The final func tional element in the sohd-waste-management system is disposal. Disposal is the ultimate fate of all solid wastes, whether they are wastes collected and transported direc tly to a landfQl site, semisolid wastes (sludge) from industrial treatment plants and air-pollution-control devices, incinerator residue, compost, or other substances from various solid-waste processing plants that are of no further use. 

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 sources of solid wastes per se are summarized in Tables 16.1 and 16.4.) However, dealing with any of them will involve some combination of the activities shown in Figure 16.2, i.e. collection, segregation and identification, processing, recycling, transport and final 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... 

In future, the developments in hydrometallurgy will need to be concerned more with environmental problems associated with pertinent processes. Hydrometallurgical processes produce a variety of waste liquors and unwanted solid products which must be treated before their final disposal. There are two main objectives in such waste treatments the first is to recover valuable impurities and unused reagents from the solutions and the second is to ensure that the release of associated materials does not pollute the environment to an unacceptable extent. 

Alternative final cover systems, such as the innovative evapotranspiration (ET) cover systems, are increasingly being considered for use at waste disposal sites, including municipal solid waste (MSW) and hazardous waste landfills when equivalent performance to conventional final cover systems can be demonstrated. Unlike conventional cover system designs that use materials with low hydraulic permeability (barrier layers) to minimize the downward migration of water from the cover to the waste (percolation), ET cover systems use water balance components to minimize percolation. These cover systems rely on the properties of soil to store water until it is either transpired through vegetation or evaporated from the soil surface. 

Another important implication is that highly permeable soil liners generally have defects, such as cracks, macropores, voids, and zones, that have not been compacted properly. One opportunity to eliminate those defects is at the time of construction. Another opportunity arises after the landfill is in operation, and the weight of overlying solid waste or of a cover over the whole system further compresses the soil. This compression, however, occurs only on the bottom liners, as there is not much overburden stress on a final cover placed over a solid waste disposal unit. This is one reason why it is more difficult to design and implement a final cover with low hydraulic conductivity than it is for a bottom liner. Not only is there lower stress acting on a cover than on a liner, but also the cover is subjected to many environmental forces, whereas the liner is not. 

Finally, there are many metal-containing solid wastes that may undergo leaching if disposed to land spent catalysts (cobalt, nickel, vanadium) spent batteries (nickel, cadmium, lithium, lead) combustion ashes etc. 

Critics of waste incineration argue that these plants often create more environmental problems than they solve. They point out, for example, that incinerators are a major source of dioxin, mercury, and halogenated hydrocarbon release into the atmosphere. In addition, incinerators are very expensive to build and to maintain, and they provide fewer jobs to members of the surrounding community than other methods of solid waste disposal. Also, companies have a dismal record of siting incinerators in disadvantaged communities, where residents suffer the worst consequences of incinerator use. Finally, waste-to-energy incinerators are of little value in tropical and subtropical countries, where the cost of plants and the availability of additional energy sources make them impractical. 

Mettler et al. found that their original procedure was not very convenient for large-scale production of the malonate intermediate 16. Safety precautions required to handle excess solid potassium cyanide were both difficult and expensive. To compound the problem even further, a large amount of Ti02-pyridine complex was generated in the first step of this process. This solid waste material required special purification treatment before its final disposal. 

Immobilization is the process of incorporating waste into a matrix material for solidification, or directly into a storage and/or final disposal container. More specifically, solidification can be defined as encapsulation of a waste in a solid of high structural integrity (Freeman, 1998). At the same time, the goal of the solidification process is the stabilization of the waste, which means that the risk posed by the waste is reduced by converting it into a less soluble and less mobile form (Freeman, 1998). 

Solid wastes are treated in a solid waste disposal area to reduce their volume and or toxicity prior to final disposal in a secured landfill. Combustible wastes can be incinerated in a slagging rotary kiln to reduce volume and toxicity. 

Disposal of municipal solid waste (MSW) is one of the most challenging environmental issues modem societies have to deal with. In Italy, the most recent data available is for the year 2004 (APAT-ONR, 2006). These data indicate an MSW production of about 3.1 X 1010 kg/ year out of a total waste production of more than 1.3 X 1011 kg/year. This impressive value corresponds to an MSW production of 533 kg/(year-person) (or about 1.5 kg/(day-person)), a value which is similar to the European Union (EU) average of537 kg/year-person (or 580 kg/year-person, if only the 15 States of the older EU are considered). In addition, the data indicate a slow but constant increase in MSW production for the last 10 years. This increase can be estimated at about two percentage points per year, both for Italy and for the EU as a whole. Finally, the same data indicate a linear correlation between MSW production and economic development expressed in terms of Gross National Product (GNP), which exists both on the national scale and, within each state, on a more local scale. 

Final end state for bulk solid wastes at the Anniston Chemical Agent Disposal Facility (ANCDF) and NECDF is yet to be determined, so these two sites are not included in estimate. 

Nonhazardous waste dust may be generated from two sources, the facility dust collection system or from spills in the storage or production areas. Dust that is not used to produce a wide specification colorant product is usually encapsulated with virgin and/or purge resin and sent to a qualified solid waste landfill for final disposal. The average annual waste dust landfilled per facility is approximately 4.5 tons. However, the facility generating the highest annual quantity of dust (20.6 tons) ships this material to an industrial waste incineration facility. 

The use of nuclear power as energy source is determined by the safe handling and deposition of the nuclear waste. High active waste solutions must be transformed into stable solid form which is suitable for final disposal. The separation of the actinides from the waste before its solidification (e.g. vitrification) is advantageous (or may be even necessary) from two points of view ... 

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