Municipal solid waste separation

Belt conveyors have been widely applied to convey mixed municipal solid waste, separation products, as well as for waste disposal. They can be used in almost every case unless for finely shredded, dry, and light material, as it is amenable to spill out the belt. Also, in cases where the load is moist, a cleaning mechanism, usually a brush, must be placed below the tail pulley to clean the belt before the return run. 

The studies on the recycling-ability of used PVC show the importance of a careful characterization, especially if mixed PVC from the municipal solid waste separation should be recycled. The analysis of the composition and a detailed knowledge of the heat history and the molecular weight of a PVC scrap are necessary before reprocessing can be applied. 

When processing municipal solid wastes, an eddy current separation unit is often used to separate aluminum and other nonferrous metals from the waste stream. This is done after removal of the ferrous metals (see Fig. 1). The eddy current separator produces an electromagnetic field through which the waste passes. The nonferrous metals produce currents having a magnetic moment that is phased to repel the moment of the appHed magnetic field. This repulsion causes the nonferrous metals to be thrown out of the process stream away from nonmetallic objects (13). 

LandtiUing of Hazardous Wastes In many states, the only disposal option available for most hazardous wastes is landfilling. The basis for the management of hazardous-wastes landfills is set forth in the Resource Conservation and Recovery Act of 1976. In general, disposal sites for hazardous wastes shoiild be separate from sites for municipal solid wastes. If separate sites are not possible, great care must be taken to ensure that separate disposal operations are maintained. 

An Ecoprofile is an assessment of the environmental and resource impacts of a waste disposal process. This paper describes ecoprofiles for six different ways of disposing the plastic fraction in municipal solid waste -two material recycling processes that include separation of the plastic waste, material recycling without separation of the plastic waste, pyrolysis, incineration with heat recovery, and landfill. 17 refs. 

It is important that the sample being tested is representative of the leachate in the landfill. Leachate sampled directly from a sump is usually representative, but care must be taken not to mix it during removal. This will disturb the sample s homogeneity and may result in components separating out. Another problem is that municipal solid waste landfill leachate will start oxidizing as soon as it leaves the sump and should probably be sampled under an inert atmosphere. 

Project Report (2008) Model design and deploy at pilot scale of the separation, collection and treatment of municipal solid waste for new urban zone. Vietnam Environmental Protection Agency (VEPA), Vietnam... 

Moeller J, Reeh U (2003) Degradation of nonylphenol ethoxylates in sewage sludge and source separated municipal solid waste under bench-scale composting conditions. Bull Environ Contam Toxicol 70 248-254... 

Municipal solid waste differs from wood biomass in that it has a negative cost. In urban centres of Canada, waste is land-filled at a cost of about 6 to 8 per tonne. While valuable inorganics such as glass and aluminum can be recovered, the costs of separation are high, and technologies are still developing. 

Composts can be made from most biodegradable materials, and could derive from many unusual sources. If it originates from municipal solid waste, however, care should be taken that no toxic and non-degradable materials remain after the supplier s separation processes. Small pieces of brick and concrete, glass and plastic (inerts), lead residues from old car batteries and cadmium from electroplated items are possible. A useful work on specifications and recommended chemical analyses of composts is the book by Bertoldi et al., 1987. 

Fig. 6. An integrated approach to the management of municipal solid waste (MSW), advocated by the U.S. EPA, that links source segregation, recycling, waste-to-energy (WTE), and landfilling in a single system. Source segregation refers to the separation of compostable and recyclable components from the balance of the trash at the point where MSW is collected. In source reduction (not shown), another action to reduce waste to landfills, changes are made in...

Each vehicle generates 500—800 pounds of residue. The annual U.S. total is about 3.5 million tons or about 1.3% of the municipal solid waste generated annually (3). The mixture is too complex to separate and recycle. Depending on the amount of glass, water, metal, and dirt present, the residue... 

Dechlorination of mixed plastics from household waste, after separation from municipal solid waste, and co-injection with coal into a blast furnace for pig iron production. The aim is to replace pulverised coal in this process (www.vinyl2010.org). 

In flow sheets for processing municipal solid waste (MSW), the objective is to separate the waste into useful materials, such as scrap metals, plastics, and refuse-derived fuels (RDFs). Usually size reduction is the... 

Recycling or reuse can take two forms preconsumer and postconsumer applications. Preconsumer recycling involves raw materials, products, and by-products that have not reached a consumer for an intended end use but are typically reused within an original process. Postconsumer recycled materials are those that have served their intended end use by a business, consumer, or institutional source and have been separated from municipal solid waste for the purpose of recycling. 

Vibrating screens are mostly used to separate fine glass, undersize material from source-separated and commingled municipal solid waste, and to process demolition and constmction materials. They are not suitable to processing... 

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