Disposal of discarded chromated copper arsenate (CCA)-treated wood in landfills raises concerns with respect to leaching of preservative compounds. When unweathered CCA-treated wood is leached using the toxicity characteristic leaching procedure (TCLP), arsenic concentrations exceed the toxicity characteristic (TC) limit of 5mg/L in most cases. The majority of discarded CCA-treated wood, howeve...

Mine tailings from an abandoned metal mine in Korea contained high concentrations of arsenic (As) and heavy metals [e.g., As: 67,336, Fe: 137,180, Cu: 764, Pb: 3,572, and Zn: 12,420 (mg/kg)]. US EPA method 6010 was an effective method for analyzing total arsenic and heavy metals concentrations. Arsenic in the mine tailings showed a high residual fraction of 89% by a sequential extraction. In To...

A large volume of waste mercury chloride catalyst (HgCl2) is generated by calcium carbide-based polyvinyl chloride production in China, which accounts for 30% of global mercury consumption. However, there are few studies on the leaching behavior and risk control of waste catalyst where mercury is in the form of HgCl2, which is more soluble than metal mercury and poses great threat to human heal...

Evaluation of metal leaching using a single leach test such as the Toxicity Characteristic Leaching Procedure (TCLP) is often questionable. The pH, redox potential (E(h)), particle size and contact time are critical variables in controlling metal stability, not accounted for in the TCLP. This paper compares the leaching behavior of metals in mineral processing waste via short-term extraction te...

This paper discusses the results of Cd, Pb and Ni immobilization using cement. Soil contamination levels were in the range 500 mg/kg to 5,000 rug/kg. and cement ratios were in the range 3% to 18%. The process was highly effective in minimizing the leaching of tested heavy metals. The measured leaching reduction results were as follows: 76% to more than 96% for Pb; 30% to more than 99% for Cd; a...

The highly leachable mercury contaminants of brine purification sludge (BPS) generated from the Hg-cell electrolysis process in chlorine production can be stabilized in the treatment procedure employing ferric-lignin derivatives (FLD) (Ligmet binder) and Portland cement (PC). The stabilization effectiveness has been examined by time-based multiple toxicity characteristic leaching procedure (TCL...

Waste molding sands from the foundry industry have been successfully used as a component in manufactured soils, but concern over metal contamination must be addressed before many states will consider this beneficial use. Since there is little data available on this topic, the purpose of this study was to characterize total and leachable metals from waste molding sands. A total elemental analysi...

Beneficial reuse of coal combustion byproducts, e.g., in highway construction, requires an evaluation of metal leaching potential. Metal leaching from high-carbon fly ash in soil mixes typical of highway embankment construction was evaluated using different soil-fly ash mixtures and three common leaching tests: the water leach test (WLT), the Toxicity Characteristic Leaching Procedure (TCLP), a...

Size-reduced samples of southern yellow pine dimensional lumber, each treated with one of five different waterborne chemical preservatives, were leached using 18-h batch leaching tests. The wood preservatives included chromated copper arsenate (CCA), alkaline copper quaternary, copper boron azole, copper citrate, and copper dimethyldithiocarbamate. An unpreserved wood sample was tested as well....

Title of Document: EVALUATION OF LEACHING PROTOCOLS FOR THE TESTING OF COAL COMBUSTION BYPRODUCTS Jason Louis Becker, Master of Science, 2010 Directed By: Associate Professor Ahmet Aydilek, Department of Civil and Environmental Engineering Beneficial reuse of coal combustion byproducts requires an evaluation of metal leaching potential. Reuse of high carbon fly ash in highway embankment constru...