Stabilized waste

Stabilizes waste containing lead, mercury, cadmium, chromium, and low-level nuclear waste. 

Produces a synthetic soil (stabilized waste with soil-like qualities) that has greater erosion resistance than natural soil, enhanced slope stability, and has a greater affinity for soluble heavy metals. 

One disadvantage associated with the Chemfix technology is a waste volume increase. After the Chemfix process solidifies/stabilizes wastes, the volume of wastes increases, resulting in a larger volume of material requiring disposal than the original volume. Chemfix claims, however, that the normal volumetric increase has been less than 20% for approximately 95% of wastes treated. 

OTD estimated that cement stabilization would produce 2,080,600 yd of stabilized wastes that could not be delisted and would have to be stored as mixed waste. The Duratek vitrification system would generate 417,000 yd of waste that may meet criteria for delisting as hazardous wastes and could be stored as only radioactive wastes (D114432, Appendix A). 

RjSnX RjSnX, RjSnXj, RSnXj RjSnXj, RSnXj Agricultural spraying, volatilization from biocidal treatments, antifouling paint sprays Incineration of organotin-treated or -stabilized waste materials. Glass coating operations to produce SnOj films... 

Baur, I. 2002. The Immobilisation of Heavy Metals and Metalloids in Cement-Stabilized Wastes A Study Focussing on the Selenium Oxyanions SeOs and Se024. PhD thesis, Swiss Federal Institute of Science and Technology (ETHZ), Zurich, Switzerland. 

Two bioassays a) 7d chronic shrimp test (Mysidopsis bahia) b) 7d chronic fish test (Menidia beryllina) Waste-to-energy (WTE) ash concrete leachates Sea-water leaching with stabilized wastes sea-water elutriation with crushed wastes decantation and/or filtration... 

WASTOXHAS is designed to assess all solid wastes likely to contain potentially hazardous contaminants, such as landfilled, re-used and solidified/stabilized wastes. Besides solid wastes per se, this approach can also be applied to a wide range of other solid media including ... 

Commonly Used Leaching Tests on Solidified/Stabilized Waste Products. .. 174... 

The characterization of leaching behavior in water of solidified/stabilized waste is crucial in most reuse or disposal scenarios. Water plays a multiple role in physico-chemical phenomena in the solid, in pollutant transfer and pollutant dispersion in the environment. 

Application context of the tests (verification tests, compliance tests, and characterization tests). Most of the compliance tests applied to solidification/ stabilization waste are short term tests involving high liquid to solid ratios and which sometimes include crushing of the materials. Such tests are not appropriate to understanding leaching behavior or for the prediction of release from solidification/stabilization wastes. 

This test, which lasts 64 days and is described in Dutch standard NEN 7345, is intended to determine leaching from products or stabilized waste materials as a function of time. The product is immersed in acidified demineralized water. This eluate is refreshed at seven specified times. Analysis of the eluates enables the leaching per square meter of product surface area and the effective diffusion coefficient to be calculated. 

The pollutant flux due to leaching depends on the physico-chemical mechanisms which govern mass transfer when solidified/stabilized waste comes into contact with water in the scenario conditions. The use of hydraulic binders has several effects on the leaching behavior of pollutants (mainly metallic species) including [22] ... 

Solidification/stabilization processes play a more important role since, in the near future, only inert or stabilized wastes should be landfilled. Solidification/stabilization process means binding the hazardous material in the hydraulic binders for safe landfilling or use in civil engineering purposes. Various types of cement, inorganic binders and pozzolanas (e.g., coal burning fly ash, lime, blast-furnace slag and similar materials) are mostly used as the... 

Cheng KY, Bishop P (1992) Metals distribution in solidified/stabilized waste forms after leaching. Hazard Waste Hazard Mater 9 163-171... 

In the phosphate washing discussed above, only a small amount of acid phosphate is used to convert contaminants into their insoluble phosphate forms. To fabricate CBPC waste forms, however, a larger amount of binder is needed, so compared to the phosphate washing, the cost of the binder is high. This condition does not mean that the volume of the stabilized waste will increase. Typically, the washed waste is loosely packed, but the fully stabilized ceramic matrix is dense. As a result, the volume does not increase and, hence, the disposal cost will remain the same. Depending on the nature of the waste and amount of the phosphate binder used, the binder cost may be the only higher cost in the CBPC treatment compared to simple acid washing. 

Wagh et al. [45] demonstrated stabilization of Cr, along with Cd, Pb, and Hg from contaminated soil and wastewater in the Ceramicrete waste form. Table 16.8 shows the contaminant levels in the waste and the wastewater, and the corresponding TCLP result for the stabilized waste. The wastewater in the Ceramicrete slurry was equal in amount to the stoichiometric water needed for the stabihzation process. Including this wastewater, the total waste loading was 77 wt%. The waste forms had open porosity of 2.7 vol% and a density of 2.17 g/cm. Compression strength was 34 MPa (4910 psi). 

Badreddine, R. Humez, A.-N. Mingelgrin, U. Benchara, A. Meducin, F. Prost, R. Retention of Trace Metals by Solidified/Stabilized Wastes Assessment of Long-Term Metal Release, Environ. Sci. Technol. 2004, 38, 1383-1398. 

Biochemical oxygen demand (BOD)—The amount of oxygen consumed by the organism in the process of stabilizing waste. 

Figure 14 Schematic diagram of a mine-waste impoundment with a combined remediation approach, including a cover to prevent O2 and water ingress, in situ mixing to geochemically stabilize waste, permeable reactive barrier in aquifer to treat subsurface drainage, and wetland for surface treatment of drainage.

Alkalinity titrations of the 15 sequential batch stabilized/solidified waste extraets and of the acetic acid digestates were performed to determine the buffering capacity of the fixed waste and the rate of leaching of alkalinity from the waste. Fig. 1 shows the pH and alkalinity releases associated with one series of extractions. These analyses show a total buffering capacity of the stabilized waste ranging from 17.6 to 19.9 meg/g (dry weight) of fixed waste, with an average of 18.3 meq/g. 

Parameters Affecting the Measurement of Hydraulic Conductivity for Solidified/Stabilized Wastes... 

Van der Sloot HA, Comans RNJ,Hjelmar O (1996) Similarities in the leaching behaviour of trace contaminants from waste, stabilized waste, construction materials and soUs. Sci Total Environ 178 111-126... 

Geochemical speciation SEM/EDX and XRD mineralogical composition of the unleached material SOLTEQ-B (a modified version of MINTEQA2 that includes Berner s model of CSH dissolution) Prediction of leaching from cement-stabilized waste [3]... 

---