Sludge waste form

As in all the waste forms discussed above, the TCLP results showed excellent retention of the hazardous contaminants in the matrix (Cd, Cr, Ag, Pb, and Zn) for both waste forms. The leaching levels for these contaminants were either below the detection limit or well below the UTS limits. While conducting this test for the sludge waste form, the investigators also tested leaching of Na, which is a bulk component, and Cs and Re, which are used as surrogates of radioactive Cs and Tc. 

Normalized Leaching Rates (g/cm day) for the Matrix Components in the Supernatant and Sludge Waste Forms. 

Polyethylene is an organic polymer with an amorphous crystalline structure, formed by the polymerization of ethylene gas. A low-density polyethylene with a processing temperature of 130 to 150°C has been evaluated in bench-scale and full-scale tests as a final waste form for evaporator concentrates, sludges, blowdown solutions, incinerator ash, and ion exchange resins. 

WASTECH, Inc., has developed a solidification and stabilization technology to produce a final waste form for soils, sludges, and liquid wastes. First, a proprietary reagent chemically bonds... 

Contaminant Concentrations in Simulated Sludge from Hanford Tanks, their Waste Forms, and... 

Waste Streams and Waste Forms Supernatant Sludge... 

The PCT was conducted on crushed waste form samples from supernatant and sludge. The fineness of the particles, compared with what is prescribed in the test procedure (see Section 17.4.1), was recognized from the beginning, and hence the actual measured... 

Leaching of Mg is much lower than leaching of other components. This might be because, overall. Mg is not as mobile as K, Na, or NO3. Moreover, some of the MgO remains unreacted in the waste form, and its solubility in alkaline water is extremely low. Both the supernatant and sludge waste streams were highly alkaline, and hence, the waste forms must have increased the alkalinity of the leachate water. This aUcalinity will reduce the leaching level of Mg. 

Several additional favorable properties of CBPCs make them an even better candidate for stabilization. The waste form is a dense matrix, generally with very good mechanical properties. Also it is nonleachable, does not degrade over time, is neutral in pH, converts even flammable waste into nonflammable waste forms, performs well within acceptable levels in radiolysis tests, and can incorporate a range of inorganic waste streams (solids, sludge, liquids, and salts). 

In the conceptual waste processing plant, supemate will be separated from sludge because the high salt content of supemate would adversely affect any of the promising waste forms. The sludge will then be dried to convert it to a more easily handled form and washed to remove most of the residual soluble salt. The sludge will then be dried again for incorporation into one of these waste forms. 

With the Fe-Mn sludge and asphalt, we also ran a differential thamal analysis (DTA) which showed an exotherm beginning around 100°C. This could be hazardous in a process vessel or in a waste form of large dimensions tightly enclosed in a container. 

A small volumetric fraction, of the transuranic (TRU) waste generates a surface dose rate exceeding 200 mrem/h. This waste, designated as remote handled (RH) TRU waste, will be received for storage at WIPP contained in metal canisters placed within licensed shipping containers. One form of RH-TRU waste is not processed and may be termed nonfixed. This waste may consist of contaminated concrete and steel, dry process sludges, etc. The fixed waste forms will include borosilicate glass and wastes fixed in ordinary concrete. 

Dissolved Air Flotation. Dissolved air flotation (DAF) is used to separate suspended soflds and oil and grease from aqueous streams and to concentrate or thicken sludges. Air bubbles carry or float these materials to the surface where they can be removed. The air bubbles are formed by pressurizing either the influent wastewater or a portion of the effluent in the presence of air. When the pressurized stream enters the flotation tank which is at atmospheric pressure, the dissolved air comes out of solution as tiny, microscopic bubbles. Dissolved air flotation is used in many wastewater treatment systems, but in the United States it is perhaps best known with respect to hazardous waste because it is associated with the Hsted waste, K048, DAF flotation soflds from petroleum refining wastewaters. Of course, the process itself is not what is hazardous, but the materials it helps to remove from refining wastewaters. 

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