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 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 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 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 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 Sulfur Polymer Stabilization Solidification Treatability Study of Mercury Contaminated Soil from the Y 12 Site written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: As a result of past operations, the Department of Energy's (DOE) Oak Ridge Y-12 National Security Complex (Y-12 Plant) has extensive mercury-contamination in building structures, soils, storm sewer sediments, and stream sediments, which are a source of pollution to the local ecosystem. Because of mercury's toxicity and potential impacts on human health and the environment, DOE continues to investigate and implement projects to support the remediation of the Y-12 site. URS and ⎢CH2M Oak Ridge LLC (UCOR) under its prime contract with DOE has cleanup responsibilities on the DOE Oak Ridge Reservation and is investigating potential mercury-contaminated soil treatment technologies through an agreement with Babcock and Wilcox (B and W) Y-12, the Y-12 operating contractor to DOE. As part of its investigations, UCOR has subcontracted with Brookhaven National Laboratory (BNL) to conduct laboratory-scale studies evaluating the applicability of the Sulfur Polymer Stabilization/Solidification (SPSS) process using surrogate and actual mixed waste Y-12 soils containing mercury (Hg) at 135, 2,000, and 10,000 ppm. SPSS uses a thermoplastic sulfur binder to convert Hg to stable mercury sulfide (HgS) and solidifies the chemically stable product in a monolithic solid final waste form to reduce dispersion and permeability. Formulations containing 40 - 60 dry wt% Y-12 soil were fabricated and samples were prepared in triplicate for Environmental Protection Agency Toxicity Characteristic Leaching Procedure (TCLP) testing by an independent laboratory. Those containing 50 and 60 wt% soil easily met the study criteria for maximum allowable Hg concentrations (47 and 1 ppb, respectively compared with the TCLP limit of 200 ppb Hg). The lowest waste loading of 40 wt% yielded TCLP Hg concentrations slightly higher (240 ppb) than the allowable limit. Since the Y-12 soil tended to form clumps, the improved leaching at higher waste loadings was probably due to reduction in particle size from friction of the soil mixing, which creates more surface area for chemical conversion. This was corroborated by the fact that the same waste loading pre-treated by ball milling to reduce particle size prior to SPSS processing yielded TCLP concentrations almost 30 times lower, and at 8.5 ppb Hg was well below EPA limits. Pre-treatment by ball milling also allowed a reduction in the time required for stabilization, thus potentially reducing total process times by 30%. Additional performance testing was conducted including measurement of compressive strength to confirm mechanical integrity and immersion testing to determine the potential impacts of storage or disposal under saturated conditions. For both surrogate and actual Y-12 treated soils, waste form compressive strengths ranged between 2,300 and 6,500 psi, indicating very strong mechanical integrity (a minimum of greater than 40 times greater than the NRC guidance for low-level radioactive waste). In general, compressive strength increases with waste loading as the soil acts as an aggregate in the sulfur concrete waste forms. No statistically significant loss in strength was recorded for the 30 and 40 wt% surrogate waste samples and only a minor reduction in strength was measured for the 43 wt% waste forms. The 30 wt% Y-12 soil did not show a significant loss in strength but the 50 wt% samples were severely degraded in immersion due to swelling of the clay soil. The impact on Hg leaching, if any, was not determined.

Download or read book Stabilization of Mercury in High PH Tank Sludges written by R. Spence and published by . This book was released on 2003 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: DOE complex contains many tank sludges contaminated with mercury. The high pH of these tank sludges typically fails to stabilize the mercury, resulting in these radioactive wastes also being characteristically hazardous or mixed waste. The traditional treatment for soluble inorganic mercury species is precipitation as insoluble mercuric sulfide. Sulfide treatment and a commercial mercury-stabilizing product were tested on surrogate sludges at various alkaline pH values. Neither the sulfide nor the commercial product stabilized the mercury sufficiently at the high pH of the tank sludges to pass the Toxicity Characteristic Leach Procedure (TCLP) treatment standards of the Resource Conservation and Recovery Act (RCRA). The commercial product also failed to stabilize the mercury in samples of the actual tank sludges.

Download or read book Treatment of Mercury Containing Waste written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A process is provided for the treatment of mercury containing waste in a single reaction vessel which includes a) stabilizing the waste with sulfur polymer cement under an inert atmosphere to form a resulting mixture and b) encapsulating the resulting mixture by heating the mixture to form a molten product and casting the molten product as a monolithic final waste form. Additional sulfur polymer cement can be added in the encapsulation step if needed, and a stabilizing additive can be added in the process to improve the leaching properties of the waste form.

Download or read book Sulfur Polymer Cement Stabilization of Elemental Mercury Mixed Waste written by and published by . This book was released on 1998 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Elemental mercury, contaminated with radionuclides, is a problem throughout the Department of Energy (DOE) complex. This report describes the development and testing of a process to immobilize elemental mercury, contaminated with radionuclides, in a form that is non-dispersible, will meet EPA leaching criteria, and has low mercury vapor pressure. In this stabilization and solidification process (patent pending) elemental mercury is mixed with an excess of powdered sulfur polymer cement (SPC) and additives in a vessel and heated to (approximately)35 C, for several hours, until all of the mercury is converted into mercuric sulfide (HgS). Additional SPC is then added and the mixture raised to 135 C, resulting in a homogeneous molten liquid which is poured into a suitable mold where is cools and solidifies. The final stabilized and solidified waste forms were characterized by powder X-ray diffraction, as well as tested for leaching behavior and mercury vapor pressure. During this study the authors have processed the entire inventory of mixed mercury waste stored at Brookhaven National Laboratory (BNL).

Download or read book Stipendisti lica na kolovanju uz naknadu li nog dohotka i korisnici kredita 1978 Scholars persons attending schools and receiving personal income and beneficiaries of credit 1978 B n ficiaires de bourses d tudes personnes en conge ducation pay et b n ficiaires de cr dits 1978 Stipendiaty lica na obu enii polu aju ie li nyj dochod i pol zuju iesja kreditom 1978 written by and published by . This book was released on 1978 with total page 112 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 USING THE SULFUR POLYMER STABILIZATION SOLIDIFICATION PROCESS TO TREAT RESIDUAL MERCURY WASTES FROM GOLD MINING OPERATIONS written by B.ADAMS BOWERMAN (J.KALB, P.WAN, R. Y.LEVIER.) and published by . This book was released on 2003 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: Large quantities of mercury are generated as a by-product during the processing of gold ore following mining operations. Newmont Mining Corporation (NMC), which operates some of the world's largest gold mines, sought a method to permanently ''retire'' its mercury by-products, thereby avoiding potential environmental liability. Sulfur Polymer Stabilization-Solidification (SPSS) is an innovative technology developed at Brookhaven National Laboratory (BNL) for treatment of mercury and mercury contaminated materials, such as soil, sludge and debris. BNL conducted a treatability study to determine the potential applicability of SPSS for treatment of Newmont mercury, and the treated product passed the U.S. Environmental Protection Agency (EPA) test for toxicity. The SPSS process has been shown to be effective on radioactive and nonradioactive mercury and mercury-contaminated materials with a pilot-scale batch system capable of producing 0.03 m{sup 3} (1 ft{sup 3}) per batch. Engineering scale-up issues are discussed and material property tests addressing these issues are described.

Download or read book Sulfur Polymer Stabilization written by and published by . This book was released on 2001 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over 1,140 yd3 of radioactively contaminated soil containing toxic mercury (Hg) and several liters of mixed-waste elemental mercury were generated during a Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) removal action at Brookhaven National Laboratory (BNL). The US Department of Energy's (DOE) Office of Science and Technology Mixed Waste Focus Area (DOE MWFA) is sponsoring a comparison of several technologies that may be used to treat these wastes and similar wastes at BNL and other sites across the DOE complex. This report describes work conducted at BNL on the application and pilot-scale demonstration of the newly developed Sulfur Polymer Stabilization/Solidification (SPSS) process for treatment of contaminated mixed-waste soils containing high concentrations ((approximately) 5,000 mg/L) of mercury and liquid elemental mercury. BNL's SPSS (patent pending) process chemically stabilizes the mercury to reduce vapor pressure and leachability and physically encapsulates the waste in a solid matrix to eliminate dispersion and provide long-term durability. Two 55-gallon drums of mixed-waste soil containing high concentrations of mercury and about 62 kg of radioactive contaminated elemental mercury were successfully treated. Waste loadings of 60 wt% soil were achieved without resulting in any increase in waste volume, while elemental mercury was solidified at a waste loading of 33 wt% mercury. Toxicity Characteristic Leaching Procedure (TCLP) analyses indicate the final waste form products pass current Environmental Protection Agency (EPA) allowable TCLP concentrations as well as the more stringent proposed Universal Treatment Standards. Mass balance measurements show that 99.7% of the mercury treated was successfully retained within the waste form, while only 0.3% was captured in the off gas system.

Download or read book Final Disposal Options for Mercury written by and published by . This book was released on 1994 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laboratory testing was completed on chemical stabilization and physical encapsulation methods that are applicable (to comply with federal and state regulations) to the final disposal of both hazardous and mixed hazardous elemental mercury waste that is in either of the following categories: (1) waste generated during decontamination and decommissioning (D and D) activities on mercury-contaminated buildings, such as Building 9201-4 at the Oak Ridge Y-12 Plant, or (2) waste stored and regulated under either the Federal Facilities Compliance Agreement or the Federal Facilities Compliance Act. Methods were used that produced copper-mercury, zinc-mercury, and sulfur-mercury materials at room temperature by dry mixing techniques. Toxicity Characteristic Leaching Procedure (TCLP) results for mercury on batches of both the copper-mercury and the sulfur-mercury amalgams consistently produced leachates with less than the 0.2-mg/L Resource Conservation and Recovery Act (RCRA) regulatory limit for mercury. The results clearly showed that the reaction of mercury with sulfur at room temperature produces black mercuric sulfide, a material that is well suited for land disposal. The results also showed that the copper-mercury and zinc-mercury amalgams had major adverse properties that make them undesirable for land disposal. In particular, they reacted readily in air to form oxides and liberate elemental mercury. Another major finding of this study is that sulfur polymer cement is potentially useful as a physical encapsulating agent for mercuric sulfide. This material provides a barrier in addition to the chemical stabilization that further prevents mercury, in the form of mercuric sulfide, from migrating into the environment.

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 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book In Situ Mercury Stabilization written by and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: BNL Royalty Project Internal Status Report. The funds from the allotment of royalty income were used to experimentally explore feasibility of related, potential new techniques based on the Environmental Sciences Department successful technology licensed for the ex situ treatment of mercury. Specifically, this work is exploring the concept of using Sulfur Polymer Cement (SPC) in an in situ application to stabilize and/or remove mercury (Hg) from surficial soil. Patent disclosure forms have been filed for this process. Soil was artificially spiked with 500 ppm Hg and a series of experiments were set up in which SPC rods were placed in the center of a mass of this soil. Some experiments were conducted at 20 C and others at 50 C. After times ranging from 11 to 24 days, these experiments were opened, photographed and the soil was sampled from discrete locations in the containers. The soil and SPC samples were analyzed for Fe and Hg by x-ray fluorescence. The Hg profile in the soil was significantly altered, with concentrations along the outer edge of the soil reduced by as much as 80% from the starting concentration. Conversely, closer to the treatment rod containing SPC, concentrations of Hg were significantly increased over the original concentration. Preliminary results for elevated temperature sample are shown graphically in Figure 2. Apparently the Hg had migrated toward the SPC and reacted with sulfur to form Hg S. This appears to be a reaction between gaseous phases of both S and Hg, with Hg having a greater vapor pressure. The concentration of low solubility HgS (i.e., low leaching properties) developed within 11 days at 50 C and 21 days at 20 C, confirming the potential of this concept.

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.