Download or read book Stabilization and Testing of Mercury Containing Wastes written by and published by DIANE Publishing. This book was released on 2001 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stabilization and Testing of Mercury Containing Wastes written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stabilization of Mercury containing Wastes Using Sulfide written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Stabilization of mercury-containing wastes has received considerable attention recently, due to concerns about air emissions from typically used thermal treatment technologies. Because of the extremely low solubility of mercuric sulfide, sulfide-induced stabilization is considered to be an effective way to immobilize mercury while minimizing mercury emissions. However, little is known of the mechanisms involved. In addition, the process of sulfide-induced stabilization of mercury-containing wastes has not been sufficiently developed; therefore, further research is needed to optimize the process-controlling parameters. In this study, the stabilization of mercury-containing wastes was performed using sodium sulfide. Primary stabilization variables such as stabilization pH, sulfide/mercury (S/Hg) molar ratio, and stabilization time were investigated. Mercury stabilization effectiveness was evaluated using the Toxicity Characteristic Leaching Procedure (TCLP) and constant pH leaching tests. The effectiveness of mercury immobilization by sulfide was tested in the presence of various concentrations of interfering ions. The results demonstrate that stabilization pH and sulfide dosage have significant effects on the stabilization efficacy. It was found that the most effective mercury stabilization occurs at pH 6 combined with a sulfide/mercury molar ratio of 1. The mercury stabilization efficiency reached 99%, even in the presence of interferents. The constant pH leaching results indicate that sulfide-treated mercury wastes produce significantly higher mercury concentrations in high pH (pH>10) leachants relative to others. Nevertheless, the mercury stabilization efficiency was still as high as 99%, even with exposure of the wastes to high pH leachants. Therefore, it is concluded that sulfide-induced stabilization is an effective way to stabilize mercury-containing wastes. The treatment optimization study indicates that the combined use of increased dosage of sulfide and ferrous ions (S/Hg = 2 and Fe/Hg = 3 at pH = 6) can significantly reduce the interferences by chloride and/or phosphate during sulfide-induced mercury immobilization. Visual MINTEQ simulation results indicate that the precipitation of cinnabar is the main mechanism that contributes to the mercury stabilization by sulfide. However, the formation of soluble mercury sulfide species at excess sulfide dosage due to the common ion effect can cause mercury remobilization from sulfide sludge under conditions that can exist in the landfills.
Download or read book Stabilization of Mercury in Waste Material from the Sulfur Bank Mercury Mine written by and published by . This book was released on 2004 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Stabilization solidification Treatment of Mercury Containing Wastes Using Reactivated Carbon and Cement written by Jian Zhang and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper presents the study results for a novel stabilization/solidification (S/S) process for high mercury wastes (Hg> 260 ppm). A relatively low-cost powder reactivated carbon (PAC) was used to stabilize mercury in solid wastes. Then the stabilized wastes were subjected to cement solidification. To improve the mercury adsorption capacity, PAC was impregnated with sulfides to obtain sulfurized PAC (SPAC). It was found that sulfurization of PAC by both CS 2 and Na 2 S significantly improved the mercury stabilization efficiency. For a Hg(NO 3) 2 solution with 40 mg/L initial Hg 2+, the equilibrium concentration of Hg 2+ was lowered to 110 æg/L by SPAC, compared with an equilibrium concentration of 4310 æg/L by PAC. The adsorption efficiency was increased by more than one order of magnitude. The mechanism of sulfurization on mercury adsorption was investigated. It is believed that formation of low solubility mercury-sulfide species was the major cause of this phenomenon. The cement-solidified wastes were subjected to TCLP leach testing and constant pH leach testing. For the constant pH leach testing, the wastes were leached at constant pH values of 2, 4, 6, 8, 10, and 12 for 14 days. From the experimental results, it was found that, once in the solidified waste form, SPAC particles retained most of the adsorbed mercury, even in the presence of high chloride concentration, possibly due to the build-up of a gel-membrane outside the carbon pores as the hydration of cement proceeded. Experimental results from constant pH leaching tests indicated that the stabilized and solidified wastes were quite stable over a wide pH range after 14 days. A model was developed to simulate mercury sorption by reactivated carbon in stirred batch reactors. The model involved the coupling of a pseudo-second order kinetic model, surface equilibrium models, including the Langmuir isotherm and the Freundlich isotherm, and a material balance equation based on batch reactors. The predicted and real carbon dosages match each other very well. It can be concluded that the S/S process by reactivated carbon and cement is a robust and effective technology for immobilization treatment of high mercury wastes.
Download or read book Technologies for the Stabilization of Elemental Mercury and Mercury containing Wastes written by Sven Hagemann and published by . This book was released on 2009 with total page 55 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Proceedings and Summary Report written by and published by . This book was released on 2001 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demonstration of ATG Process for Stabilizing Mercury 260 Ppm Contaminated Mixed Waste Mixed Waste Focus Area OST Reference 2407 written by and published by . This book was released on 1999 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury contaminated wastes in many forms are present at various U.S. Department of Energy (DOE) sites. Based on efforts led by the Mixed Waste Focus Area (MWFA) and its Mercury Working Group (HgWG), the inventory of wastes contaminated with 260 ppm mercury and with radionuclides stored at various DOE sites is estimated to be approximately 6,000 m3). At least 26 different DOE sites have this type of mixed low-level waste in their storage facilities. Extraction methods are required to remove mercury from waste containing260 ppm levels, but below 260 ppm Hg contamination levels the U.S. Environmental Protection Agency (EPA) does not require removal of mercury from the waste. Steps must still be taken, however, to ensure that the final waste form does not leach mercury in excess of the limit for mercury prescribed in the Resource Conservation and Recovery Act (RCRA) when subjected to the Toxicity Characteristic Leaching Procedure (TCLP). At this time, the limit is 0.20 mg/L. However, in the year 2000, the more stringent Universal Treatment Standard (UTS) of 0.025 mg/L will be used as the target endpoint. Mercury contamination in the wastes at DOE sites presents a challenge because it exists in various forms, such as soil, sludges, and debris, as well as in different chemical species of mercury. Stabilization is of interest for radioactively contaminated mercury waste (
Download or read book Fiscal Year 2001 Budget Authorization Request written by United States. Congress. House. Committee on Science. Subcommittee on Energy and Environment and published by . This book was released on 2001 with total page 1114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Industrial Scale Processes For Stabilizing Radioactively Contaminated Mercury Wastes written by T. E. Broderick and published by . This book was released on 2003 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper describes two industrial-scaled processes now being used to treat two problematic mercury waste categories: elemental mercury contaminated with radionuclides and radioactive solid wastes containing greater than 260-ppm mercury. The stabilization processes were developed by ADA Technologies, Inc., an environmental control and process development company in Littleton, Colorado. Perma-Fix Environmental Services has licensed the liquid elemental mercury stabilization process to treat radioactive mercury from Los Alamos National Laboratory and other DOE sites. ADA and Perma-Fix also cooperated to apply the>260-ppm mercury treatment technology to a storm sewer sediment waste collected from the Y-12 complex in Oak Ridge, TN.
Download or read book Hazardous Waste written by United States. Government Accountability Office and published by . This book was released on 2005 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hazardous Waste written by John B. Stephenson (au) and published by DIANE Publishing. This book was released on 2006-08 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: The EPA regulates haz. wastes (such as mercury) under the Resource Conservation & Recovery Act (RCRA). Under RCRA, mercury-containing haz. waste must meet specific treatment standards before land disposal. But, certain difficult to manage waste due, in part, to its large particle size, can follow alternate debrisÓ standards that provide diverse treatment options. This report examines: the mechanisms that EPA uses to track the treatment & disposal of debrisÓ & the quantity of this waste: the extent to which EPA, states, & ind. share a common understand. of the types of debrisÓ that can be treated & disposed of as debris: & EPA & state controls that are in place to monitor compliance with EPA's treat. & disposal require. for debrisÓ. Ill.
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 2003 with total page 882 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demonstrations to Support Change to The 260 Ppm Mercury Treatment Regulations written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Department of Energy (DOE) and the U.S. Environmental Protection Agency (EPA) are working together to justify a change in the Land Disposal Restriction for High Mercury (>260 ppm mercury) waste. The present regulation that requires roasting or retorting is based on recovering and recycling the mercury in the waste. However, most of DOE's High Mercury waste is radioactively contaminated, eliminating the possibility of its recycle. The radioactive mercury recovered must be amalgamated and disposed. In addition, concern over fugitive emissions from retorting and roasting operations has raised the question of whether such processing is environmentally sound. A change to the regulation to allow stabilization and disposal would reduce the overall environmental threat, if the stabilization process can reduce the leachability of the mercury to regulatory levels. Demonstrations are underway to gather data showing that the High Mercury waste can be safely stabilized. At the same time, comparison tests are being conducted using an improved form of the baseline retorting technology to better quantify the fugitive emission problem and determine the full capability of thermal desorption systems. A first round of demonstrations stabilizing mercury in soil from Brookhaven National Laboratory (BNL) has been completed. Four groups demonstrated their process on the waste: 1) BNL demonstrated its Sulfur Polymer Stabilization/Solidification process; 2) Nuclear Fuel Services used their DeHg (de-merk) process, 3) Allied Technology Group used chemical stabilization, and 4) Sepradyne demonstrated their vacuum thermal desorption system. All groups were successful in their tests, reaching regulatory levels for mercury leachability. Data for each group will be presented. DOE, EPA, and the University of Cincinnati are presently working on another series of tests involving treatment of surrogate sludge and soil by commercial vendors. Protocols that better determine the waste form's ability to withstand leaching are being used to analyze the stabilized surrogates. Results of these and the previous demonstrations will be used to determine whether the High Mercury treatment regulation can be safely changed.
Download or read book Stabilisation Solidification Treatment and Remediation written by Abir Al Tabbaa and published by CRC Press. This book was released on 2005-04-14 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Stabilisation/Solidification Treatment and Remediation - Advances in S/S for Waste and Contaminated Land contains 39 papers, summaries of the four keynote lectures and the seven State of Practice reports presented at the International Conference organized by the EPSRC-funded network STARNET (Stabilisation/solidification treatment and remediation).
Download or read book Federal Register written by and published by . This book was released on 1980-11-25 with total page 1234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Demonstration Results on the Effects of Mercury Speciation on the Stabilization of Wastes written by and published by . This book was released on 1999 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mercury-contaminated wastes are currently being stored at approximately 19 Department of Energy sites, the volume of which is estimated to be about 16m(sup)3. These wastes exist in various forms including soil, sludges, and debris, which present a particular challenge regarding possible mercury stabilization methods. This reports provides the test results of three vendors, Allied Technology Group, IT Corporation, and Nuclear Fuel Services, Inc., that demonstrate the effects of mercury speciation on the stabilization of the mercury wastes. Mercury present in concentrations that exceed 260 parts per million must be removed by extraction methods and requires stabilization to ensure that the final wasteforms leach less than 0.2mg/L of mercury by the Toxicity Characteristic Leaching Procedure or 0.025 mg/L using the Universal Treatment Standard.
