Waste solids properties

At the Shawnee Test Facility, major emphasis has been placed on the use of adipic acid in conjunction with forced oxidation of calcium sulfite to calcium sulfate, since this system results in better sludge dewatering properties and reduced waste solids disposal costs. Furthermore, the more tightly closed liquor loop,... 

Thus, it seems that regardless of the extent of reaction achieved in the first reactor, the limestone will be efficiently consumed in the remainder of the reactor train and dewatering system. The solids carryover in the thickener overflow, therefore, do not appear to have a substantial effect on the overall limestone utilization by the system they do, however, impact on the settling properties of the solids generated as will be discussed later when addressing the properties of the waste solids. 

Another characteristic of the waste solids was the deterioration of their settling properties with time. This effect was observed on various occasions, most notably during a filter repair downtime. Solids with excellent settling properties had been... 

H. Alter and J. J. Duim, Jr., Solid Waste Conversion to Energy Current European and U.S. Practices, Marcel Dekker, Inc., New York, 1980, Chapt. 5 H. Alter andj. A. CampbeU, in J. L. Jones and S. B. Radding, eds.. The Preparation and Properties ofDensified Refuse-Derived Fuel, Thermal Conversion of Solid Wastes andBiomass, American Chemical Society, Washington, D.C., 1980, pp. 127—142. 

Types of Solid Wastes The term solid wastes is aU-inchisive and encompasses all sources, types of classifications, compositions, and properties. As a basis for subsequent discussions, it will be helpful to define the various types of solid wastes that are generated. It is important to note that the definitions of solid-waste terms and the classifications vary greatly in prac tice and in literature. Consequently, the use of published data requires considerable care, judgment, and common sense. The following definitions are intended to serve as a guide. 

Properties of Solid Wastes Information on the properties of solid wastes is important in evaluating alternative equipment needs, systems, and management programs and plans. 

Chemical Composition Information on the chemical composition of sohd wastes is important in evaluating alternative processing and recoveiy options. If solid wastes are to be used as fuel, the four most important properties to be known are ... 

The two different, but related, eonsiderations in waste disposal are hazard eontrol and loss prevention in the treatment and disposal operations, and the eontrol of environmental hazards. With gas and liquid streams the eontrol of on-site hazards arising from the ehemieal properties and proeessing operations generally follows the prineiples summarized in earlier ehapters. The measures neeessary with solid wastes may, however, differ, partieularly if they are heterogeneous in nature and disposed of on land. 

Studies of the incineration of liquid and solid wastes must determine the rates at which hazardous compounds are released into the vapor phase or are transformed in the condensed phase, particularly when the hazardous materials make up a small fraction of the liquid burned. We must be particularly concerned with understanding the effects of the major composition and property variations that might be encountered in waste incinerator operations—for example, fluctuations in heating value and water content, as well as phase separations. Evidence of the importance of variations in waste properties on incinerator performance has been demonstrated by the observation of major smges in emissions from rotary-kiln incinerators as a consequence of the rapid release of volatiles during the feeding of unstable materials into the incinerator. 

According to APME, energy recovery should be the preferred waste disposal route for polymeric materials that are very contaminated, bonded, laminated to other materials, or are at the end of their performance with respect to their physical/chemical properties. This paper takes a detailed look at energy recovery from municipal solid waste combustors, and considers the effect of polymeric materials. 

During the last decade many industrial processes shifted towards using solid acid catalysts (6). In contrast to liquid acids that possess well-defined acid properties, solid acids contain a variety of acid sites (7). Sohd acids are easily separated from the biodiesel product they need less equipment maintenance and form no polluting by-products. Therefore, to solve the problems associated with liquid catalysts, we propose their replacement with solid acids and develop a sustainable esterification process based on catalytic reactive distillation (8). The alternative of using solid acid catalysts in a reactive distillation process reduces the energy consumption and manufacturing pollution (i.e., less separation steps, no waste/salt streams). 

As baghouse dust accounts for a minimum of the total foundry solid waste, less attention is placed on characterizing this wastestream. Few data are available giving its physical properties and chemical composition. Visually, it is a very fine powder, dark gray in color. The dust may demonstrate physical properties that are similar to clay soils. 

Comparable fuels. In order to promote the recycling of materials with high fuel values, certain materials that are burned as fuels are excluded from the definition of solid waste, provided that they meet certain specifications (i.e., are of a certain degree of purity). This is to ensure that the material does not exceed certain levels of toxic constituents and physical properties that might impede burning. Materials that meet this specification are considered comparable to pure or virgin fuels. 

More than 90% of municipal solid waste is directly disposed of on land, the vast majority of it in an unsatisfactory manner. Open and burning dumps are common in many developing countries these contribute to water and air pollution and provide food and breeding grounds for birds, rats, insects, and other carriers of disease. The presence of these dumps often reduces the property value of nearby land and residences. 

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