1
|
Li F, Shaw S, Libby C, Preciado N, Bicer B, Tamizhmani G. A review of toxicity assessment procedures of solar photovoltaic modules. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 174:646-665. [PMID: 38159503 DOI: 10.1016/j.wasman.2023.12.034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/30/2023] [Revised: 11/20/2023] [Accepted: 12/14/2023] [Indexed: 01/03/2024]
Abstract
Environmental management of solar photovoltaic (PV) modules is attracting attention as a growing number of field-operated PV modules approach end of life (EoL). PV modules may contain small amounts of toxic metals, and the procedures for assessing and regulating the toxic metal content and release of such materials at EoL differ widely across nations. This paper provides an overview of the metal composition of PV modules and common procedures for toxicity assessment through extensive research and review of technical literature and legislative documents. This review focuses on three primary aspects: first, it explores the distribution of toxic elements within current and emerging PV module designs, with a specific focus on obtaining representative samples for proportional toxicity testing within different module laminate areas. Second, it examines a sampling standard and the diverse toxicity testing methods and regulations employed in various regions, encompassing standards like the Environmental Protection Agency (EPA) Test Method 1311 (Toxicity Characteristic Leaching Procedure, TCLP) in the U.S., Restriction of Hazardous Substances (RoHS) in Europe, and the Waste Extraction Test (WET) in California. Third, the review examines the sources of variability in toxicity testing outcomes, including techniques for securing homogeneous samples from non-uniform PV modules, selecting particle sizes representative of landfill conditions in extracted samples, determining appropriate leachate characteristics such as leaching agents and pH levels, and considering factors like test duration and temperatures. In summary, this review summarizes relevant regulations and offers a comprehensive overview of the strengths and limitations associated with several toxicity assessment procedures currently in practice.
Collapse
Affiliation(s)
- Fang Li
- Photovoltaic Reliability Laboratory, Arizona State University, Mesa, AZ 85212, USA.
| | | | | | - Nini Preciado
- Photovoltaic Reliability Laboratory, Arizona State University, Mesa, AZ 85212, USA
| | - Bulent Bicer
- Photovoltaic Reliability Laboratory, Arizona State University, Mesa, AZ 85212, USA
| | | |
Collapse
|
2
|
Chandra A, Siddiqua S. Sustainable utilization of chemically depolymerized polyethylene terephthalate (PET) waste to enhance sand-bentonite clay liners. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 166:346-359. [PMID: 37210958 DOI: 10.1016/j.wasman.2023.04.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 03/23/2023] [Accepted: 04/16/2023] [Indexed: 05/23/2023]
Abstract
Polyethene terephthalate (PET) waste poses major environmental harm which can be minimized by reusing it in clay soil stabilization. In general, various polymers are known to reduce hydraulic conductivity and increase the shear strength of clays. However, the application of the effect of a chemically depolymerized form of PET, i.e., Bis (2-Hydroxyethyl) terephthalate (BHET) has not been performed as an additive in Compacted Clay Liners (CCLs) for landfills. This research focuses on the effect of the air curing period (1 and 28 days) on the hydromechanical behavior of BHET-treated SBM (0, 1, 2, 3, and 4 % by dry weight). Results from One Dimensional Consolidation tests showed that an increase in BHET content reduced both compressibility and hydraulic conductivity of SBM due to pore clogging mechanism of swollen BHET hydrogel, however, hydraulic conductivity reduced over 28 days of curing due to loss in re-swelling availability of the hydrogel, thereby allowing less tortuous paths to flow. Results from Consolidated-Drained Direct Shear tests showed that for 1 and 28-days curing, BHET treatment to SBM increased the cohesion (c') due to strong polymer interparticle bridging, however, polymer coating over the sand grains causes a reduction in its surface roughness to decrease the frictional angle (ϕ'). SEM (Scanning Electron Microscopy) and EDX (Energy-dispersive X-ray spectroscopy) analysis on BHET-treated specimens support the flocculation of bentonite, polymer bridging of sand and clay-sand polymer links. A significant Pb2+ removal capacity was also observed with BHET-treated SBM from the batch tests. FTIR (Fourier Transform Infrared Spectroscopy) analysis on batch sorption specimens confirms the role of the carbonyl groups (C = O) and hydroxyl groups (OH) present in the BHET structure indicating the possibility to adsorb Pb2+. The findings of the study suggested that a mechanism of interaction exists between sand-bentonite and BHET polymer and it can be adopted in CCLs design.
Collapse
Affiliation(s)
- Alok Chandra
- Faculty of Applied Science, School of Engineering, University of British Columbia, Kelowna, BC V1V1V7, Canada.
| | - Sumi Siddiqua
- Faculty of Applied Science, School of Engineering, University of British Columbia, Kelowna, BC V1V1V7, Canada.
| |
Collapse
|
3
|
Growth and Mechanical Characterization of Mycelium-Based Composites towards Future Bioremediation and Food Production in the Material Manufacturing Cycle. Biomimetics (Basel) 2022; 7:biomimetics7030103. [PMID: 35997423 PMCID: PMC9397049 DOI: 10.3390/biomimetics7030103] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Revised: 07/11/2022] [Accepted: 07/23/2022] [Indexed: 11/24/2022] Open
Abstract
Today’s architectural and agricultural practices negatively impact the planet. Mycelium-based composites are widely researched with the aim of producing sustainable building materials by upcycling organic byproducts. To go further, this study analyzed the growth process and tested the mechanical behavior of composite materials grown from fungal species used in bioremediation. Agricultural waste containing high levels of fertilizers serves as the substrate for mycelium growth to reduce chemical dispersal in the environment. Compression and three-point bending tests were conducted to evaluate the effects of the following variables on the mechanical behavior of mycelium-based materials: substrate particle size (with or without micro-particles), fungal species (Pleurotus ostreatus and Coprinus comatus), and post-growth treatment (dried, baked, compacted then dried, and compacted then baked). Overall, the density of the material positively correlated with its Young’s and elastic moduli, showing higher moduli for composites made from substrate with micro-particles and for compacted composites. Compacted then baked composites grown on the substrate with micro-particles provided the highest elastic moduli in compression and flexural testing. In conclusion, this study provides valuable insight into the selection of substrate particle size, fungal species, and post-growth treatment for various applications with a focus on material manufacturing, food production, and bioremediation.
Collapse
|
4
|
Qi C, Weinell CE, Dam-Johansen K, Wu H. A review of blasting waste generation and management in the ship repair industry. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 300:113714. [PMID: 34547570 DOI: 10.1016/j.jenvman.2021.113714] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 08/20/2021] [Accepted: 09/07/2021] [Indexed: 06/13/2023]
Abstract
Solid blasting waste generated from coating removal during ship repair and maintenance poses environmental challenges. This paper presents a review of the generation, characterization, and treatment of blasting waste in the ship repair industry. The quantities, properties, and environmental impacts of the generated blasting waste are summarized and analyzed, and the results indicate that blasting waste has a high generation rate and/or high toxicity. As alternatives to landfill, available blasting waste treatment methods include hydrometallurgical leaching, physical/physicochemical separation, thermal treatment, and direct utilization in the production of building materials. The advantages and disadvantages of these treatments are reviewed and compared. The production of building materials from blasting waste is currently attractive owning to its economic benefits and technical simplicity, whereas recycling blasting waste for high-value applications is gradually gaining research interest. The high dependence of the choice and performance of treatment methods on the waste type and characteristics is highlighted. The results emphasize the interest in conducting more research on physiochemical and thermal properties and the environmental effects of blasting waste. This review suggests that future research should focus more on paint waste management because of the restricted application of dry abrasive blasting and the development of nonabrasive blasting methods in the ship repair industry.
Collapse
Affiliation(s)
- Chunping Qi
- The Hempel Foundation Coatings Science and Technology Centre (CoaST), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800, Kgs. Lyngby, Denmark
| | - Claus E Weinell
- The Hempel Foundation Coatings Science and Technology Centre (CoaST), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800, Kgs. Lyngby, Denmark
| | - Kim Dam-Johansen
- The Hempel Foundation Coatings Science and Technology Centre (CoaST), Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800, Kgs. Lyngby, Denmark; CHEC Research Center, Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800, Kgs. Lyngby, Denmark
| | - Hao Wu
- CHEC Research Center, Department of Chemical and Biochemical Engineering, Technical University of Denmark, Building 229, 2800, Kgs. Lyngby, Denmark.
| |
Collapse
|
5
|
Levin R, Zilli Vieira CL, Rosenbaum MH, Bischoff K, Mordarski DC, Brown MJ. The urban lead (Pb) burden in humans, animals and the natural environment. ENVIRONMENTAL RESEARCH 2021; 193:110377. [PMID: 33129862 PMCID: PMC8812512 DOI: 10.1016/j.envres.2020.110377] [Citation(s) in RCA: 62] [Impact Index Per Article: 20.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 10/14/2020] [Accepted: 10/15/2020] [Indexed: 05/23/2023]
Abstract
Centuries of human activities, particularly housing and transportation practices from the late 19th century through the 1980's, dispersed hundreds of millions of tons of lead into our urban areas. The urban lead burden is evident among humans, wild and domesticated animals, and plants. Animal lead exposures closely mirror and often exceed the lead exposure patterns of their human partners. Some examples: Pigeons in New York City neighborhoods mimicked the lead exposures of neighborhood children, with more contaminated areas associated with higher exposures in both species. Also, immediately following the lead in drinking water crisis in Flint MI in 2015, blood lead levels in pet dogs in Flint were 4 times higher than in surrounding towns. And combining lead's neurotoxicity with urban stress results in well-characterized aggressive behaviors across multiple species. Lead pollution is not distributed evenly across urban areas. Although average US pediatric lead exposures have declined by 90% since the 1970s, there remain well defined neighborhoods where children continue to have toxic lead exposures; animals are poisoned there, too. Those neighborhoods tend to have disproportionate commercial and industrial lead activity; a history of dense traffic; older and deteriorating housing; past and operating landfills, dumps and hazardous waste sites; and often lead contaminated drinking water. The population there tends to be low income and minority. Urban wild and domesticated animals bear that same lead burden. Soil, buildings, dust and even trees constitute huge lead repositories throughout urban areas. Until and unless we begin to address the lead repositories in our cities, the urban lead burden will continue to impose enormous costs distributed disproportionately across the domains of the natural environment. Evidence-based research has shown the efficacy and cost-effectiveness of some US public policies to prevent or reduce these exposures. We end with a series of recommendations to manage lead-safe urban environments.
Collapse
Affiliation(s)
- Ronnie Levin
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, 02215, USA.
| | - Carolina L Zilli Vieira
- Department of Environmental Health, Harvard T.H. Chan School of Public Health, Boston, MA, 02215, USA.
| | - Marieke H Rosenbaum
- Department of Infectious Disease and Global Health, Cummings School of Veterinary Medicine at Tufts University, North Grafton, MA, 01536, USA.
| | - Karyn Bischoff
- New York State Animal Health Diagnostic Center, Ithaca, NY, 14853, USA.
| | | | - Mary Jean Brown
- Department of Social and Behavioral Sciences, Harvard T.H. Chan School of Public Health, Boston, MA, 02215, USA.
| |
Collapse
|
6
|
O'Shea MJ, Vigliaturo R, Choi JK, McKeon TP, Krekeler MPS, Gieré R. Alteration of yellow traffic paint in simulated environmental and biological fluids. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 750:141202. [PMID: 32853929 PMCID: PMC7657991 DOI: 10.1016/j.scitotenv.2020.141202] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 07/16/2020] [Accepted: 07/21/2020] [Indexed: 05/27/2023]
Abstract
Pollution from heavy metals in urban environments is a topic of growing concern because many metals, including Pb and Cr, are a human health hazard. Exposure to Pb and Cr has been linked to the inhibition of neurological development as well as toxic effects on many organs. Yellow traffic paint (YTP) is a mixture that contains organic polymers, binders, and pigments, which in some cases consist of crocoite (PbCrO4) that may be coated by silica. The primary aim of this study was to investigate the behavior of the crocoite pigment grains within YTP and their silica coatings in simulated environmental and human body conditions. To do this, both YTP and asphalt were collected in Philadelphia, PA, USA. These samples as well as a standard PbCrO4 were investigated with powder X-ray diffraction, X-ray fluorescence, environmental scanning electron microscopy (ESEM), transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Using this multi-analytical approach, mineral phases were determined in the YTP, their shape, dimensional distributions, crystallinity, and chemical composition, as well as elemental distributions before and after experimental interactions. Three batch dissolution experiments with YTP, asphalt, and standard PbCrO4 were performed to simulate ingestion, inhalation, and environmental interaction with rainwater. Elemental releases were determined with inductively coupled plasma-optical emission spectrometry, and results indicated that little (ingestion) to no (environmental and inhalation) Pb and Cr were leached from the YTP during the three experimental procedures. This is likely due to the silica coating that encapsulates the crocoite particles, which persisted during all interactions. The ESEM results for YTP showed dimensional reductions after interactions with all three fluids. The silica coating must be further explored to determine how it breaks down in real environmental conditions.
Collapse
Affiliation(s)
- Michael J O'Shea
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316, USA.
| | - Ruggero Vigliaturo
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316, USA
| | - Jessica K Choi
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316, USA
| | - Thomas P McKeon
- Center of Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, PA 19104-6316, USA
| | - Mark P S Krekeler
- Department of Geology and Environmental Earth Science, Miami University Hamilton, Hamilton, OH 45011, USA; Department of Geology and Environmental Earth Science, Miami University, Oxford, OH 45056, USA
| | - Reto Gieré
- Department of Earth and Environmental Science, University of Pennsylvania, Philadelphia, PA 19104-6316, USA; Center of Excellence in Environmental Toxicology, University of Pennsylvania, Philadelphia, PA 19104-6316, USA
| |
Collapse
|
7
|
Gupt CB, Bordoloi S, Sekharan S, Sarmah AK. A feasibility study of Indian fly ash-bentonite as an alternative adsorbent composite to sand-bentonite mixes in landfill liner. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2020; 265:114811. [PMID: 32512424 DOI: 10.1016/j.envpol.2020.114811] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 05/03/2020] [Accepted: 05/12/2020] [Indexed: 06/11/2023]
Abstract
Multi-layered engineered landfill consists of the bottom liner layer (mainly bentonite clay (B)) upon which the hazardous wastes are dumped. In current practice, sand (S) is mixed with bentonite to mitigate the adverse effects of using bentonite alone in the liner layer. Incorporation of waste and unutilized fly ash (FA) as an amendment material to B has been explored in terms of its hydro-mechanical properties, but not gauged its adsorption potential. Indian subcontinent primarily relies on the thermal power source, and FA dumps have already reached its full capacity. The objective of this study is to explore the adsorption characteristics of four B-FA composite mixes sourced within India, considering Pb2+ as a model contaminant. The effect of fly ash type, fly ash amendment rate and adsorbate concentration was explored in the current study and juxtaposed with B-S mixes, based on 960 batch adsorption tests. Both B-FA and B-S mixes reached equilibrium adsorption capacity within 65 min. At higher adsorbate concentrations (commonly observed in the liner), B-FA mixes exhibited superior adsorption capacity, mainly one mixed with Neyvelli fly ash (NFA). The effect of higher amendment rate had little impact on the adsorption capacity at different concentration, but gradually decreased the percentage removal of Pb2+. The B-S mix showed a drastic decrease in percentage removal at higher adsorbate concentration among all tested mixes. Systematic characterization including geotechnical properties, microstructure and chemical analysis was also done to interpret the obtained results. Both Freundlich and Langmuir models fitted the isotherm data well for all B-FA mixes. The maximum adsorption capacity from the isotherm was correlated to easily measurable Atterberg limits by two empirical relationships.
Collapse
Affiliation(s)
- Chandra Bhanu Gupt
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Sanandam Bordoloi
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India; Department of Civil and Environmental Engineering, Hong Kong University of Science and Technology, Hong Kong Special Administrative Region
| | - Sreedeep Sekharan
- Department of Civil Engineering, Indian Institute of Technology Guwahati, Guwahati, 781039, Assam, India
| | - Ajit K Sarmah
- Department of Civil and Environmental Engineering, The Faculty of Engineering, The University of Auckland, Private Bag 92019, 1142, Auckland, New Zealand.
| |
Collapse
|
8
|
Blaisi NI, Clavier KA, Roessler JG, Chung J, Townsend TG, Al-Abed SR, Bonzongo JCJ. Material- and Site-Specific Partition Coefficients for Beneficial Use Assessments. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:9626-9635. [PMID: 31356749 DOI: 10.1021/acs.est.9b01756] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Partition coefficient (Kd) values available in the literature are often used in fate and transport modeling conducted as part of beneficial use risk assessments for industrial byproducts. Because element partitioning depends on soil properties as well as characteristics of the byproduct leachate, site-specific Kd values may lead to more accurate risk assessment. In this study, contamination risk to groundwater of beneficially reused byproducts was assessed using batch leaching tests on waste to energy bottom ash and coal combustion fly ash. Leachates were equilibrated with eight different soils to obtain the waste-soil-specific Kd,exp values for the metals of interest. The Kd,exp values were used as inputs in the Industrial Waste Management Evaluation Model to demonstrate the degree to which Kd estimates affect risk assessment outcomes. Measured Kd,exp values for the most part fell within the large range of Kd values reported in the literature, but IWEM results using default Kd values for some types of soils resulted in overestimated risk compared to those derived from Kd,exp values. Modeled concentration at the receptor location was much lower for some elements for those soils with high concentrations of iron and aluminum.
Collapse
Affiliation(s)
- Nawaf I Blaisi
- Department of Environmental Engineering, College of Engineering , Imam Abdulrahman Bin Faisal University , P.O Box 1982, Dammam , Saudi Arabia
| | - Kyle A Clavier
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| | - Justin G Roessler
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| | - Jaeshik Chung
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
- Center for Water Resource Cycle , Korea Institute of Science and Technology , Seoul 136-791 , Republic of Korea
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| | - Souhail R Al-Abed
- National Risk Management Research Laboratory , U.S. Environmental Protection Agency , 26 West Martin Luther King Drive , Cincinnati , Ohio 45268 , United States
| | - Jean-Claude J Bonzongo
- Department of Environmental Engineering Sciences , University of Florida , PO Box 116450 Gainesville , Florida 32611-6450 , United States
| |
Collapse
|
9
|
Xie H, Zhang L, Li H, Li S, Chen K, Zhang B, Zhou M. Ultrasonic-enhanced replacement of lead in lead hydrometallurgy process from lead leaching solution. ROYAL SOCIETY OPEN SCIENCE 2019; 6:190042. [PMID: 31417712 PMCID: PMC6689618 DOI: 10.1098/rsos.190042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2019] [Accepted: 06/04/2019] [Indexed: 06/10/2023]
Abstract
In this paper, ultrasonic-enhanced replacement of lead by zinc in lead leaching solution was studied. The effects of reaction time, rotational speed, temperature, concentration of leaching solution and the ratio of the surface area of the zinc plate immersed in the leaching solution to the volume of leaching solution (S : V) were studied under both conventional and ultrasonic conditions. The optimum ultrasonic-assisted replacement conditions were as follows: the S : V of 0.04 (4 cm2 100 ml-1), reaction temperature of 30°C, replacement time of 30 min and the concentration of leaching solution is 5 g l-1, leading to a lead replacement rate of 94.84%. Compared with the conventional replacement process, the reaction time of ultrasonic-enhanced substitution could be reduced to one half, and the demand of reaction temperature, leaching solution concentration and other conditions were decreased accordingly. Introducing ultrasonic into the replacement reaction is promising to reduce the energy consumption in the hydrometallurgical industry also caters to the demands of environment protection.
Collapse
Affiliation(s)
- Huimin Xie
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
| | - Libo Zhang
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
| | - Haoyu Li
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
| | - Shiwei Li
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
| | - Kaihua Chen
- State Key Laboratory of Complex Nonferrous Metal Resources Clean Utilization, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
- Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming, Yunnan 650093, People's Republic of China
| | - Bo Zhang
- Zhengzhou Institute of Multipurpose Utilization of Mineral Resources, Chinese Academy of Geological Sciences, Zhengzhou, Henan 450006, People's Republic of China
| | - Mi Zhou
- School of Metallurgy, Northeastern University, Shenyang, Liaoning 110819, People's Republic of China
| |
Collapse
|
10
|
Slabe VA, Anderson JT, Cooper J, Brown B, Ortiz P, Buchweitz J, McRuer D, Katzner T. Lead in piscivorous raptors during breeding season in the Chesapeake Bay region of Maryland and Virginia, USA. ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY 2019; 38:862-871. [PMID: 30698866 DOI: 10.1002/etc.4376] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2018] [Revised: 01/23/2019] [Accepted: 01/23/2019] [Indexed: 06/09/2023]
Abstract
Sources of lead exposure of many bird species are poorly understood. We analyzed blood lead concentrations from osprey (n = 244; Pandion haliaetus) and bald eagles (n = 68; Haliaeetus leucocephalus) and documented potential sources of lead they may encounter. Adult bald eagles had higher blood lead concentrations than did adult osprey. However, blood lead concentrations of nestlings were similar for both species. Although 62% of osprey had detectable lead concentrations ( x¯ = 1.99 ± 4.02 μg/dL, mean ± standard deviation [SD]), there was no difference in the detection frequency or lead concentrations between osprey adults and nestlings. Likewise, we found no differences in the detection frequency or lead concentrations in osprey adults and nestlings from high- and low-salinity areas. Of the bald eagle samples tested, 55% had detectable lead levels ( x¯ = 6.23 ± 10.74 μg/dL). Adult bald eagles had more detectable and higher lead concentrations than did nestlings or pre-adults. Among environmental samples, paint had the highest lead concentrations, followed by sediment, blue catfish (Ictalurus furcatus), and gizzard shad (Dorosoma cepedianum). There was no correlation between blood lead concentrations of osprey adults and their offspring. Our results indicate that, in the Chesapeake Bay region of Maryland and Virginia (USA), there are multiple sources by which piscivorous raptors may be exposed to lead. Environ Toxicol Chem 2019;38:862-871. © Published 2019 Wiley Periodicals Inc. on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.
Collapse
Affiliation(s)
- Vincent A Slabe
- Division of Forestry and Natural Resources, West Virginia University, Morgantown, West Virginia, USA
| | - James T Anderson
- Division of Forestry and Natural Resources, West Virginia University, Morgantown, West Virginia, USA
| | - Jeff Cooper
- Virginia Department of Game and Inland Fisheries, Richmond, Virginia, USA
| | - Bracken Brown
- Division of Forestry and Natural Resources, West Virginia University, Morgantown, West Virginia, USA
| | - Patricia Ortiz
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, Idaho, USA
| | - John Buchweitz
- Department of Pathobiology and Diagnostic Investigation, Michigan State University, East Lansing, Michigan, USA
| | - Dave McRuer
- Wildlife Center of Virginia, Waynesboro, Virginia, USA
| | - Todd Katzner
- US Geological Survey, Forest and Rangeland Ecosystem Science Center, Boise, Idaho, USA
| |
Collapse
|
11
|
Monroy Sarmiento L, Roessler JG, Townsend TG. Trace element mobility from coal combustion residuals exposed to landfill leachate. JOURNAL OF HAZARDOUS MATERIALS 2019; 365:962-970. [PMID: 30616307 DOI: 10.1016/j.jhazmat.2018.11.028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 10/24/2018] [Accepted: 11/07/2018] [Indexed: 06/09/2023]
Abstract
Coal combustion residuals (CCR) from energy generation may pose a risk to human health and the environment if not managed properly. Because of new regulations for the management of CCR, generators must dispose of these materials in lined landfill units similar to municipal solid waste (MSW) landfills. Generators could opt to construct dedicated units for CCR (monofilling) or by placing them in MSW landfills (co-disposal). The distinct chemical environments of these two disposal scenarios may cause a noticeable difference in pollutant mobilization from CCR. Batch leaching tests were employed to simulate CCR monofilling and MSW co-disposal. Landfill leachate promoted higher release of As and V from fly ash compared to ash leached with synthetic rainwater. Changes in pH do not account for the added release and other characteristics intrinsic to MSW leachate play a dominant role. When fly ash disposal is modeled, As release is forecasted to be almost 690 tons under a co-disposal scenario, compared to 18 tons when ash is monofilled. These observations highlight the need for better long-term planning when deciding the disposal routes for municipal, commercial, and industrial byproducts.
Collapse
Affiliation(s)
- Linda Monroy Sarmiento
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL, 32611-6450, USA
| | - Justin G Roessler
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL, 32611-6450, USA
| | - Timothy G Townsend
- Department of Environmental Engineering Sciences, University of Florida, PO Box 116450, Gainesville, FL, 32611-6450, USA.
| |
Collapse
|
12
|
Turner A, Lewis M. Lead and other heavy metals in soils impacted by exterior legacy paint in residential areas of south west England. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 619-620:1206-1213. [PMID: 29734599 DOI: 10.1016/j.scitotenv.2017.11.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 11/02/2017] [Accepted: 11/03/2017] [Indexed: 06/08/2023]
Abstract
Legacy paint on publicly-accessible structures in residential areas of Plymouth, UK (a bridge parapet, hospital railings, a goal frame, urban street paving and a telephone kiosk) and local paint-contaminated soils have been analysed for lead and other heavy metals (chromium, zinc and barium) by X-ray fluorescence spectrometry. Lead was detected in all paints analysed (n=56) apart from two fragments of yellow road markings, with maximum concentrations exceeding 300gkg-1. Soils were contaminated by Pb to varying degrees that depended on the condition and Pb content of the paint applications and the nature and vegetation of the soil, with a maximum concentration of 27gkg-1 and a maximum enrichment factor normalised to grain size and regional baseline soil of 270. While Cr showed no clear contamination in soils that could be attributed to paint, contamination from this source was evident for Zn in soil by the goal frame and for Ba and Zn in soil by the bridge parapet. Application of a physiologically-based extraction test to the soils revealed stomach bioaccessibilities that were variable among the samples and between the metals but that were greatest for Zn and lowest for Cr. With the exception of Cr, bioaccessibility generally decreased in the intestine, with mean intestinal bioaccessibilities relative to total metal of about 6% for Pb and Ba, 0.9% for Cr and 1.6% for Zn. From both a health and environmental perspective, Pb is the heavy metal of greatest concern because of its common occurrence at high concentrations in legacy paints, coupled with a relatively high bioaccessibility and well-documented chronic neurotoxicity. Public exposure to Pb in residential areas may arise through direct contact with paint or soil or via the intrusion of contaminated geosolids to the household on shoes or as airborne dust.
Collapse
Affiliation(s)
- Andrew Turner
- School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK.
| | - Madeleine Lewis
- School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth PL4 8AA, UK
| |
Collapse
|
13
|
Pinto PX, Al-Abed SR. Assessing metal mobilization from industrial lead-contaminated soils in an urban site. APPLIED GEOCHEMISTRY : JOURNAL OF THE INTERNATIONAL ASSOCIATION OF GEOCHEMISTRY AND COSMOCHEMISTRY 2017; 83:31-40. [PMID: 30245545 PMCID: PMC6145492 DOI: 10.1016/j.apgeochem.2017.01.025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
A series of leaching and partitioning tests (Toxicity Characteristic Leaching Procedure (TCLP), Synthetic Precipitation Leaching Procedure (SPLP), Controlled Acidity Leaching Protocol (CALP), Acid Neutralization Capacity (ANC), and sequential extraction) were applied to three different soils to study the potential mobility of metals into groundwater. Two of these soils were lead (Pb)-contaminated soils (Hotspot 1 and Hotspot 2) collected from an urban site associated with lead smelting and other industrial operations. The third sample (Stockpile) was soil affected by previous contamination in the area, removed from residential properties, stockpiled, and selected to be used as fill material in the studied site. The TCLP and CALP showed that Pb could be released from both hotspots, but were not released in the acidic rainfall extraction fluid of the SPLP. The sequential extraction showed that Pb in the hotspot soils was associated with the carbonate fraction, while As was associated with the Fe and Mn oxides. The stockpile released traces of Pb or As in the TCLP and CALP, but the ANC only released Pb under acidic conditions and the SPLP did not release Pb or As. Overall, the projected repository with Stockpile would not pose imminent danger to groundwater because, under the expected environmental conditions, Pb and As tend to remain in the solid phase.
Collapse
Affiliation(s)
- Patricio X. Pinto
- Pegasus Technical Services, Inc. 46 E. Hollister St. Cincinnati, OH 45219, United States
| | - Souhail R. Al-Abed
- U.S. Environmental Protection Agency, National Risk Management Research Laboratory, 26 W. Martin Luther King Dr. Cincinnati, OH 45268, United States
| |
Collapse
|
14
|
Cerceau CI, Carvalho CDF, Rabelo ACS, Dos Santos CG, Gonçalves SMD, Varejão EVV. Recovering lead from cupel waste generated in gold analysis by Pb-Fire assay. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2016; 183:771-776. [PMID: 27652581 DOI: 10.1016/j.jenvman.2016.08.052] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Revised: 08/17/2016] [Accepted: 08/21/2016] [Indexed: 06/06/2023]
Abstract
Because of its precision and accuracy, Pb-Fire assay is the most employed method for gold analysis in geological materials. At the second stage of the method, namely cupellation, lead is oxidized to PbO which is absorbed by the cupel, leading to metallic gold as a tiny bend at the bottom of the recipient. After cupellation, cupel becomes highly contaminated with lead, making its disposal a serious risk of environmental contamination. In the present work, a leaching process for removing lead from cupel waste is proposed, which allowed for removing 96% of PbO by weight. After a precipitation step, 92.0% of lead was recovered from leachates in the form of PbSO4. Lead in the solid wastes left by the extraction was above the limit established by Brazilian legislation and these were classified as non-hazardous. Finally, secondary effluents generated after the precipitation step presented lead content more than twenty times lower than that of leachates from cupel waste. Tons of cupel waste are annually generated from gold analysis by Pb-Fire assay. Thus, the proposed method can contribute to prevent the discharge of high amounts of lead into the environment. Also, recovery of lead can help to partially meet the industrial demand for lead compounds.
Collapse
Affiliation(s)
- Cristiane Isaac Cerceau
- Departamento de Química, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, 35400-000, Ouro Preto, Minas Gerais, Brazil; Departamento de Química, Universidade Federal de Viçosa, Av. PH Rolfs s/n, 36570-900, Viçosa, Minas Gerais, Brazil
| | - Cornélio de Freitas Carvalho
- Departamento de Química, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, 35400-000, Ouro Preto, Minas Gerais, Brazil.
| | - Ana Carolina Silveira Rabelo
- Departamento de Química, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, 35400-000, Ouro Preto, Minas Gerais, Brazil
| | - Cláudio Gouvea Dos Santos
- Departamento de Química, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, 35400-000, Ouro Preto, Minas Gerais, Brazil
| | - Sabrina Mayra Dias Gonçalves
- Departamento de Química, Universidade Federal de Ouro Preto, Campus Morro do Cruzeiro, 35400-000, Ouro Preto, Minas Gerais, Brazil
| | | |
Collapse
|
15
|
Tian XM, Wu YF. Recent development of recycling lead from scrap CRTs: A technological review. WASTE MANAGEMENT (NEW YORK, N.Y.) 2016; 57:176-186. [PMID: 26365873 DOI: 10.1016/j.wasman.2015.09.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Revised: 09/03/2015] [Accepted: 09/03/2015] [Indexed: 06/05/2023]
Abstract
Cathode ray tubes (CRTs) contain numerous harmful substances with different functions. Lead is found in the funnel glass of CRTs. Improperly treated toxic lead may pose significant risks to human health and the environment. This paper reviews and summarizes existing technological processes on the recycling of lead from waste CRTs, including pyrometallurgy, hydrometallurgy, and product-regeneration. The present situation, advantages, and disadvantages of these techniques are described in detail. Generally, pyrometallurgy shows better practicability in recovery lead from waste CRT than hydrometallurgy and hydrometallurgy, in view of environmental impact, energy-consumption, product formats and safety and maturity of technology. Moreover, the gaps in the existing technologies were identified and recommendations for future research were provided.
Collapse
Affiliation(s)
- Xiang-Miao Tian
- Institute of Recycling Economy, Beijing University of Technology, No. 100, Pingleyuan Street, Chaoyang District, Beijing 100124, PR China
| | - Yu-Feng Wu
- Institute of Recycling Economy, Beijing University of Technology, No. 100, Pingleyuan Street, Chaoyang District, Beijing 100124, PR China.
| |
Collapse
|
16
|
Powell JT, Jain P, Smith J, Townsend TG, Tolaymat TM. Does Disposing of Construction and Demolition Debris in Unlined Landfills Impact Groundwater Quality? Evidence from 91 Landfill Sites in Florida. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:9029-9036. [PMID: 26130423 PMCID: PMC7534698 DOI: 10.1021/acs.est.5b01368] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
More than 1,500 construction and demolition debris (CDD) landfills operate in the United States (U.S.), and U.S. federal regulations do not require containment features such as low-permeability liners and leachate collection systems for these facilities. Here we evaluate groundwater quality from samples collected in groundwater monitoring networks at 91 unlined, permitted CDD landfills in Florida, U.S. A total of 460,504 groundwater sample results were analyzed, with a median of 10 years of quarterly or semiannual monitoring data per site including more than 400 different chemical constituents. Downgradient concentrations of total dissolved solids, sulfate, chloride, iron, ammonia-nitrogen, and aluminum were greater than upgradient concentrations (p < 0.05). At downgradient wells where sulfate concentrations were greater than 150 mg/L (approximately 10% of the maximum dissolved sulfate concentration in water, which suggests the presence of leachate from the landfill), iron and arsenic were detected in 91% and 43% of samples, with median concentrations of 1,900 μg/L and 11 μg/L, respectively. These results show that although health-based standards can be exceeded at unlined CDD landfills, the magnitude of detected chemical concentrations is generally small and reflective of leached minerals from components (wood, concrete, and gypsum drywall) that comprise the bulk of discarded CDD by mass.
Collapse
Affiliation(s)
- Jon T. Powell
- Corresponding author. Current address: Yale University, 380 Edwards St., New Haven, CT 06511, USA. Tel.: +1 352 682 4007, Fax: +1-352-331-4842,
| | - Pradeep Jain
- Innovative Waste Consulting Services, LLC, 6628 NW 9 Blvd. Suite 3, Gainesville, FL 32605, USA
| | - Justin Smith
- Innovative Waste Consulting Services, LLC, 6628 NW 9 Blvd. Suite 3, Gainesville, FL 32605, USA
| | - Timothy G. Townsend
- Department of Environmental Engineering Sciences, University of Florida, P.O. BOX 116450, Gainesville, FL 32611-6450, USA
| | - Thabet M. Tolaymat
- Land and Nanotechnology Research, National Risk Management Research Laboratory, US Environmental Protection Agency, 26 W. Martin Luther King St., Cincinnati, OH 45268, USA
| |
Collapse
|
17
|
Shu Z, Axe L, Jahan K, Ramanujachary KV. Metal leaching from the bridge paint waste in the presence of steel grit. CHEMOSPHERE 2015; 119:1105-1112. [PMID: 25460749 DOI: 10.1016/j.chemosphere.2014.09.061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 09/18/2014] [Accepted: 09/21/2014] [Indexed: 06/04/2023]
Abstract
The disposal of paint waste from bridge rehabilitation is a significant issue because of the potential release of contaminants and the consequent impact to human health and the environment. In this study, leaching behavior of paint waste was evaluated for 24 bridges in New York State. Although elevated Pb (5-168,090 mg kg(-1)) and other metal concentrations were observed in the paint samples, leaching experiments that included the toxicity characteristic leaching procedure (TCLP) and the multiple extraction procedure (MEP) revealed toxicity characteristic (TC) limits were not exceeded. The relatively low concentrations observed are attributed to the use of iron-based abrasives (steel grit) in the paint removal process. In this research, trace metals are hypothesized to be sequestered through interactions with iron oxide coatings formed on the steel grit surface resulting in reduced leachable concentrations. Through sequential extraction iron oxides were observed at 11.03% by wt and X-ray diffraction (XRD) further corroborated the presence of iron oxide coatings on the steel grit surface. Sequential extraction demonstrated that less than 6.8% of Pb, Cr, and Ba were associated with the exchangeable and carbonate forms, while greater contributions were found with iron oxides. The largest fraction, however, greater than 80%, was associated with the residual phase comprised of minerals in the paint including SiO2 and TiO2.
Collapse
Affiliation(s)
- Zhan Shu
- Department of Civil and Environmental Engineering, Newark College of Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA.
| | - Lisa Axe
- Department of Civil and Environmental Engineering, Newark College of Engineering, New Jersey Institute of Technology, Newark, NJ 07102, USA
| | - Kauser Jahan
- Department of Civil and Environmental Engineering, Rowan University, Glassboro, NJ 08028, USA
| | | |
Collapse
|
18
|
López A, Lobo A. Emissions of C&D refuse in landfills: a European case. WASTE MANAGEMENT (NEW YORK, N.Y.) 2014; 34:1446-1454. [PMID: 24824964 DOI: 10.1016/j.wasman.2014.04.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/14/2014] [Revised: 03/17/2014] [Accepted: 04/06/2014] [Indexed: 06/03/2023]
Abstract
A field study was developed in a new landfill for refuse from construction and demolition (C&D) material recovery plants of small size (4 Ha.) in Europe, with the aim of evaluating the liquid and gas emissions in this type of facility at a large scale. It included characterization of the materials, monitoring leachate and gas quantity and composition. Besides thermometers, piezometers and sampling ports were placed in several points within the waste. This paper presents the data obtained for five years of the landfill life. The materials disposed were mainly made up of wood and concrete, similar to other C&D debris sites, but the amount of gypsum drywall (below 3% of the waste) was significantly smaller than other available studies, where percentages above 20% had been reported. Leachate contained typical C&D pollutants, such as different inorganic ions and metals, some of which exceeded other values reported in the literature (conductivity, ammonium, lead and arsenic). The small net precipitation in the area and the leachate recirculation into the landfill surface help explain these higher concentrations, thus highlighting the impact of liquid to solid (L/S) ratio on leachate characteristics. In contrast to previous studies, neither odor nuisances nor significant landfill gas over the surface were detected. However, gas samples taken from the landfill inside revealed sulfate reducing and methanogenic activity.
Collapse
Affiliation(s)
- Ana López
- Environmental Engineering Group, Department of Science and Techniques of Water and the Environment, University of Cantabria, Avd. Los Castros s/n, Santander 39005, Cantabria, Spain.
| | - Amaya Lobo
- Environmental Engineering Group, Department of Science and Techniques of Water and the Environment, University of Cantabria, Avd. Los Castros s/n, Santander 39005, Cantabria, Spain.
| |
Collapse
|
19
|
Din MI, Hussain Z, Mirza ML, Shah AT, Athar MM. Adsorption optimization of lead (II) using Saccharum bengalense as a non-conventional low cost biosorbent: isotherm and thermodynamics modeling. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2014; 16:889-908. [PMID: 24933891 DOI: 10.1080/15226514.2013.803025] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
In the present study a novel biomass, derived from the pulp of Saccharum bengalense, was used as an adsorbent material for the removal of Pb (II) ions from aqueous solution. After 50 minutes contact time, almost 92% lead removal was possible at pH 6.0 under batch test conditions. The experimental data was analyzed using Langmuir, Freundlich, Timken and Dubinin-Radushkevich two parameters isotherm model, three parameters Redlich-Peterson, Sip and Toth models and four parameters Fritz Schlunder isotherm models. Langmuir, Redlich-Peterson and Fritz-Schlunder models were found to be the best fit models. Kinetic studies revealed that the sorption process was well explained with pseudo second-order kinetic model Thermodynamic parameters including free energy change (AG degrees), enthalpy change (AH degrees) and entropy change (AS degrees) have been calculated and reveal the spontaneous, endothermic and feasible nature of the adsorption process. The thermodynamic parameters of activation (deltaG(#), deltaH(#) and deltaS(#)) were calculated from the pseudo-second order rate constant by using the Eyring equation. Results showed that Pb (II) adsorption onto SB is an associated mechanism and the reorientation step is entropy controlled.
Collapse
|
20
|
|
21
|
Magalhães FB, de Freitas Carvalho C, Corrêa Netto Carvalho EL, Yoshida MI, Gouvêa dos-Santos C. Rendering wastes obtained from gold analysis by the lead-fusion fire-assay method non-hazardous. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2012; 110:110-115. [PMID: 22771892 DOI: 10.1016/j.jenvman.2012.06.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Revised: 06/04/2012] [Accepted: 06/19/2012] [Indexed: 06/01/2023]
Abstract
The classical method of melting lead by fire-assay (Pb-FA) is the most frequently used analytical technique in gold prospection. The crucible solid waste which is generated in this process is usually characterized by chemical and mineralogical composition, granulometric size distribution, and classified according to Brazilian Environmental Regulations. This study demonstrates how acid leaching can be used to remove lead from waste originally classified as hazardous by treatment with hydrochloric and nitric acids followed by chemical precipitation in sodium metasilicate solution. It is shown that for every 1000 kg of hazardous waste, 995.6 kg of non-harzardous waste can be recovered.
Collapse
|