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Cui C, Yan D, Chen C, Liu M, Li L, Wang J. Investigation of the emission and leaching behavior of characteristic heavy metals in sintered bricks prepared from oil-based drill cutting residues. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 190:217-226. [PMID: 39357302 DOI: 10.1016/j.wasman.2024.09.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Revised: 08/21/2024] [Accepted: 09/27/2024] [Indexed: 10/04/2024]
Abstract
Oil-based drill cutting residues (OBDCR) are hazardous waste generated by the thermal desorption of oil-based drill cuttings. Recently, the utilization of OBDCR as building materials has attracted extensive attention, but the environmental risks during preparation and long-term usage remained unclear. In this study, OBDCR with a 40 % (wt./wt.) mixing ratio was used to prepare sintered bricks, and the emission and leaching behaviors of Ba, Mn, Zn, Ni, Cr, and Pb were investigated. The results indicated that the addition of OBDCR in bricks showed insignificant increase in the emission of Ba, Mn, Zn, Ni, and Cr, whereas the emission of Pb slight decreased from 10.5 to 8.6 μg/m3. The volatilization rates of these heavy metals were considerably low, with Ni showed the highest volatilization rate of only 1.45 % in OBDCR bricks. Moreover, the leaching behavior of Ba, Mn, Zn, Ni, Cr, and Pb in bricks were studied. The results indicated that surface wash-off was the main controlling leaching mechanism of Ba and Cr, whereas the leaching of Mn, Zn, Ni, and Pb was controlled by diffusion. The Elovich and second-order kinetic equation were identified as the leaching models for Mn, Zn, Pb, and Ni. The life-time leaching predictions of OBDCR bricks indicated that the leaching of Ni and Mn after 10 and 20 years of leaching were 0.1529, 0.257, 0.1530, and 0.274 mg/L, respectively, exceeding the relevant standards. Therefore, the leaching risks of Ni and Mn should be emphasized when using OBDCR bricks with a 40 % OBDCR mixing ratio.
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Affiliation(s)
- Changhao Cui
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Solid Waste Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Dahai Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Solid Waste Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Chao Chen
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Solid Waste Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Meijia Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Solid Waste Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Li Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Solid Waste Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
| | - Jian Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; Institute of Solid Waste Pollution Control Technology, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
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2
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Zhao G, Tian C, Wu P, Zhang X, Wang Z, Chen X, Xiong Z, Zhao Y, Zhang J. Effect of oxide interactions on chromium speciation transformation during simulated municipal solid waste incineration. J Environ Sci (China) 2024; 142:11-20. [PMID: 38527877 DOI: 10.1016/j.jes.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Revised: 11/01/2023] [Accepted: 11/02/2023] [Indexed: 03/27/2024]
Abstract
Chromium released during municipal solid waste incineration (MSWI) is toxic and carcinogenic. The removal of chromium from simulated MSWI flue gas by four sorbents (CaO, bamboo charcoal (BC), powdered activated carbon (PAC), and Al2O3) and the effects of four oxides (SiO2, Al2O3, Fe2O3, and CaO) on chromium speciation transformation were investigated. The results showed that the removal rates of total Cr by the four sorbents were Al2O3 < CaO < PAC < BC, while the removal rates of Cr(VI) by the four sorbents were Al2O3 < PAC < BC < CaO. CaO had a strong oxidizing effect on Cr(III), while BC and PAC had a better-reducing effect on Cr(VI). SiO2 was better for the reduction of Na2CrO4 and K2CrO4 above 1000°C due to its strong acidity, and the addition of CaO significantly inhibited the reduction of Cr(VI). MgCrO4 decomposed above 700°C to form MgCr2O4, and the reaction between MgCrO4 and oxides also existed in the form of a more stable trivalent spinel. Furthermore, when investigating the effect of oxides on the oxidation of Cr(III) in CrCl3, it was discovered that CaO promoted the conversion of Cr(III) to Cr(VI), while the presence of chlorine caused chromium to exist in the form of Cr(V), and increasing the content of CaO and extending the heating time facilitated the oxidation of Cr(III). In addition, silicate, aluminate, and ferrite were generated after the addition of SiO2, Al2O3, and Fe2O3, which reduced the alkalinity of CaO and had an important role in inhibiting the oxidation of Cr(III). The acidic oxides can not only promote the reduction of Cr(VI) but also have an inhibitory effect on the oxidation of Cr(III) ascribed to alkali metals/alkaline earth metals, and the proportion of acidic oxides can be increased moderately to reduce the generation of harmful substances in the hazardous solid waste heat treatment.
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Affiliation(s)
- Guodong Zhao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Chong Tian
- School of Power and Mechanical Engineering, Wuhan University, Wuhan 430072, China.
| | - Peidong Wu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xuguang Zhang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Zhikang Wang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Xiaoxiang Chen
- School of Environmental Engineering, Wuhan Textile University, Wuhan 430200, China
| | - Zhuo Xiong
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; National Environmental Protection Engineering Technology Center for Trace Elements Pollution Control and Low Carbon Utilization of Coal, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Yongchun Zhao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; National Environmental Protection Engineering Technology Center for Trace Elements Pollution Control and Low Carbon Utilization of Coal, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Junying Zhang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China; National Environmental Protection Engineering Technology Center for Trace Elements Pollution Control and Low Carbon Utilization of Coal, Huazhong University of Science and Technology, Wuhan 430074, China.
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3
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Kapiamba KF, Owusu SY, Wu Y, Huang YW, Jiang Y, Wang Y. Examining the Oxidation States of Metals in Aerosols Emitted by Electronic Cigarettes. Chem Res Toxicol 2024; 37:1113-1120. [PMID: 38957009 DOI: 10.1021/acs.chemrestox.4c00033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/04/2024]
Abstract
Electronic cigarettes (ECs) emit many toxic substances, including metals, that can pose a threat to users and the environment. The toxicity of the emitted metals depends on their oxidation states. Hence, this study examines the oxidation states of metals observed in EC aerosols. X-ray photoelectron spectroscopy analysis of the filters that collected EC aerosols identified the oxidation states of five primary metals (based on surface sample analysis), including chromium(III) (close to 100%) under low power setting while a noticeable amount of chromium(VI) (15%) at higher power settings of the EC, and copper(II) (100%), zinc(II) (100%), nickel(II) (100%), lead(II) (65%), and lead(IV) (35%) regardless of power settings. This observation indicates that the increased temperature due to higher power settings could alter the oxidation states of certain metals. We noted that many metals were in their lesser toxic states; however, inhaling these metals may still pose health risks.
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Affiliation(s)
- Kashala Fabrice Kapiamba
- Department of Chemical, Environmental, and Materials Engineering, University of Miami, Miami, Florida 33146, United States
| | - Stephen Yaw Owusu
- Department of Chemistry, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Yangtao Wu
- Department of Civil and Environmental Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon TU428, Hong Kong
| | - Yue-Wern Huang
- Department of Biological Sciences, Missouri University of Science and Technology, Rolla, Missouri 65409, United States
| | - Yi Jiang
- Department of Civil and Environmental Engineering, the Hong Kong Polytechnic University, Hung Hom, Kowloon TU428, Hong Kong
| | - Yang Wang
- Department of Chemical, Environmental, and Materials Engineering, University of Miami, Miami, Florida 33146, United States
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4
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Thery G, Juillot F, Calmels D, Bollaert Q, Meyer M, Quiniou T, David M, Jourand P, Ducousso M, Fritsch E, Landrot G, Morin G, Quantin C. Heating effect on chromium speciation and mobility in Cr-rich soils: A snapshot from New Caledonia. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 922:171037. [PMID: 38373451 DOI: 10.1016/j.scitotenv.2024.171037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 02/14/2024] [Accepted: 02/15/2024] [Indexed: 02/21/2024]
Affiliation(s)
- Gaël Thery
- Géosciences Paris-Saclay, GEOPS, UMR CNRS 8148, Université Paris Saclay, 91405 Orsay Cedex, France; Institut de Recherche pour le Développement, IRD, ERL 206 IMPMC, 98848 Nouméa Cedex, New Caledonia
| | - Farid Juillot
- Institut de Recherche pour le Développement, IRD, ERL 206 IMPMC, 98848 Nouméa Cedex, New Caledonia; Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, UMR 7590 CNRS, Sorbonne Université, MNHN, IRD, 75005 Paris Cedex 05, France.
| | - Damien Calmels
- Géosciences Paris-Saclay, GEOPS, UMR CNRS 8148, Université Paris Saclay, 91405 Orsay Cedex, France
| | - Quentin Bollaert
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, UMR 7590 CNRS, Sorbonne Université, MNHN, IRD, 75005 Paris Cedex 05, France
| | - Michael Meyer
- Institut des Sciences Exactes et Appliquées, ISEA, EA, Université de la Nouvelle-Calédonie, Nouméa, New Caledonia
| | - Thomas Quiniou
- Institut des Sciences Exactes et Appliquées, ISEA, EA, Université de la Nouvelle-Calédonie, Nouméa, New Caledonia
| | - Magali David
- Institut de Recherche pour le Développement, IRD, ERL 206 IMPMC, 98848 Nouméa Cedex, New Caledonia
| | - Philippe Jourand
- Laboratoire des Symbioses Tropicales et Mediterranéennes (LSTM), Université Montpellier, UMR IRD 040, UMR CIRAD 082, Campus International de Baillarguet, Montpellier, France
| | - Marc Ducousso
- Laboratoire des Symbioses Tropicales et Mediterranéennes (LSTM), Université Montpellier, UMR IRD 040, UMR CIRAD 082, Campus International de Baillarguet, Montpellier, France
| | - Emmanuel Fritsch
- Géosciences Paris-Saclay, GEOPS, UMR CNRS 8148, Université Paris Saclay, 91405 Orsay Cedex, France; Institut de Recherche pour le Développement, IRD, ERL 206 IMPMC, 98848 Nouméa Cedex, New Caledonia
| | - Gautier Landrot
- Synchrotron SOLEIL, l'Orme les Merisiers, Saint Aubin, France
| | - Guillaume Morin
- Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, IMPMC, UMR 7590 CNRS, Sorbonne Université, MNHN, IRD, 75005 Paris Cedex 05, France
| | - Cécile Quantin
- Géosciences Paris-Saclay, GEOPS, UMR CNRS 8148, Université Paris Saclay, 91405 Orsay Cedex, France
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5
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Li Z, Yu D, Wang X, Liu X, Xu Z, Wang Y. A novel strategy of tannery sludge disposal - converting into biochar and reusing for Cr(VI) removal from tannery wastewater. J Environ Sci (China) 2024; 138:637-649. [PMID: 38135427 DOI: 10.1016/j.jes.2023.04.014] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/13/2023] [Accepted: 04/13/2023] [Indexed: 12/24/2023]
Abstract
Tannery sludge with high chromium content has been identified as hazardous solid waste due to its potential toxic effects. The safety disposal and valorization of the tannery sludge remains a challenge. In this study, the chromium stabilization mechanism was systematically investigated during chromium-rich tannery sludge was converted to biochar and the removal performance of the sludge biochar (SBC) for Cr(VI) from tannery wastewater was also investigated. The results showed that increase in pyrolysis temperature was conductive to the stabilization of Cr and significant reduction of the proportion of Cr(VI) in SBC. It was confirmed that the stabilization of chromium mainly was attributed to the embedding of chromium in the C matrix and the transformation of the chromium-containing substances from the amorphous Cr(OH)3 to the crystalline state, such as (FeMg)Cr2O5. The biochar presented high adsorption capacity of Cr(VI) at low pH and the maximal theoretical adsorption capacity of SBC produced at 800°C can reach 352 mg Cr(VI)/g, the process of which can be well expressed by Langmuir adsorption isotherm and pseudo second order model. The electrostatic effect and reduction reaction were dominantly responsible for the Cr(VI) adsorption by SBC800. Overall, this study provided a novel strategy for the harmless disposal and resource utilization for the solid waste containing chromium in leather industry.
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Affiliation(s)
- Zhiwei Li
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Di Yu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xingdong Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Xuejiao Liu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Zhen Xu
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Yin Wang
- CAS Key Laboratory of Urban Pollutant Conversion, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China; Zhejiang Key Laboratory of Urban Environmental Processes and Pollution Control, CAS Haixi Industrial Technology Innovation Center in Beilun, Ningbo 315830, China; Key Laboratory of Urban Environment and Health, Ningbo Observation and Research Station, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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6
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Zhao R, Zhang X, Zhou Y, Li J, Guo B, Oyama K, Tokoro C. Influence of elevated temperature on the species and mobility of chromium in ferrous sulfate-amended contaminated soil. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2024; 356:120457. [PMID: 38503231 DOI: 10.1016/j.jenvman.2024.120457] [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: 09/26/2023] [Revised: 12/22/2023] [Accepted: 02/20/2024] [Indexed: 03/21/2024]
Abstract
Ferrous sulfate (FeSO4) combined with acid pretreatment is usually employed to remediate contaminated soils containing Cr(VI). However, the long-term efficiency of this stabilization method is important for its sustainability. In this study, a gradient temperature-elevating exposure test was employed to investigate the stability of Cr in FeSO4-remediated soil when exposed to elevated temperatures (40 °C, 120 °C, and 500 °C), possibly caused by hot weather and/or wildfires. The results of chemical extraction and X-ray absorption near edge structure spectroscopy (XANES) showed that the Cr(VI) in contaminated soil was successfully transformed to Cr(III) after stabilization, resulting in the dramatic decrease of water-leachable Cr(VI). The stabilization efficiency was further improved under 40 °C treatment after 30 days. Subsequently, the 120 °C treatment (7 days) had relatively little effect on the Cr speciation and mobility in soils. However, even one day of 500 °C calcination resulted in the deterioration of stabilization efficiency, and the water-leachable Cr(VI) re-increased and became higher than the Chinese environmental standards (total Cr 15 mg/L, Cr(VI) 5 mg/L) for the classification of hazardous solid wastes. XANES results reflected that heating at 500 °C facilitate the formation of Cr2O3, which was mainly caused by thermal decomposition and dehydration of Cr(OH)3 in the soil. Besides, the transformation of Cr species resulted in the enhanced association of Cr with the most stable residual fraction (88.3%-91.6%) in soil. Based on chemical extraction results, it was suggested that the oxidation of Cr(III) to Cr(VI) contributed to the re-increased mobility of Cr(VI) in soil. However, the XANES results showed that almost no significant re-oxidization of Cr(III) to Cr(VI) happened after heating at 500 °C, which was probably caused by XANES linear combination fits (LCF) uncertainties. Moreover, the changes in soil properties, including a rise in pH to a slightly alkaline range and/or the decomposition of organic matter, possibly contributed to the enhanced mobility of Cr(VI) in soil. This study contributes to clarifying the mobility and transformation of Cr in contaminated soils and provides a support for the sustainable management of remediated soils.
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Affiliation(s)
- Ruolin Zhao
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu province, 210023, China
| | - Xinqing Zhang
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu province, 210023, China
| | - Yiwen Zhou
- National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, Guangdong province, 510650, China
| | - Jining Li
- School of Environment, Nanjing Normal University, Nanjing, Jiangsu province, 210023, China; National-Regional Joint Engineering Research Center for Soil Pollution Control and Remediation in South China, Guangdong Key Laboratory of Integrated Agro-environmental Pollution Control and Management, Institute of Eco-environmental and Soil Sciences, Guangdong Academy of Sciences, Guangzhou, Guangdong province, 510650, China.
| | - Binglin Guo
- School of Civil Engineering, Hefei University of Technology, Hefei, Anhui province, 230009, China.
| | - Keishi Oyama
- Faculty of Science and Engineering, Waseda University, Tokyo, 169-8555, Japan
| | - Chiharu Tokoro
- Faculty of Science and Engineering, Waseda University, Tokyo, 169-8555, Japan; Faculty of Engineering, The University of Tokyo, Tokyo, 113-8656, Japan
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7
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Zhao Y, Zhang C, Ma L, Li J, Tan P, Fang Q, Chen G. Effects of temperature on the migration behaviour of arsenic and chromium in tannery sludge under CO 2 gasification. JOURNAL OF HAZARDOUS MATERIALS 2024; 461:132663. [PMID: 37783141 DOI: 10.1016/j.jhazmat.2023.132663] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 08/24/2023] [Accepted: 09/26/2023] [Indexed: 10/04/2023]
Abstract
To reduce heavy metals (HMs) contamination from tannery sludge, this study investigated the migration behaviour of arsenic (As) and chromium (Cr) at 700-900 °C using CO2 gasification. The HMs enrichment results showed that As contents of ash decreased (6.42→1.87 mg/kg) while Cr contents increased (41.40→78.24 mg/kg) over 700-900 °C. More Si-O bonds and fewer Ca-O bonds with increasing temperature in ash primarily determined this migration behaviour of HMs. Meanwhile, the proportions of toxic As(III) and Cr(VI) declined from 96.02% and 64.26-76.96% and 21.24%, forming As(0) and Cr(III) with less toxicity. This reduction was conducted via two pathways: (i) carbon reduced As(III)/Cr(VI) and (ii) carbon reduced Fe(II)/Fe(III) to Fe(0), then Fe(0) reduced As(III)/Cr(VI) assisted with carbon via Fe(0)→Fe(II)→Fe(III). However, free calcium ions oxidized As(0)/Cr(III) to As(III)/Cr(VI) at 700 ○C. At higher temperatures, silicate glass conversion of ash immobilized free calcium ions and barely oxidized HMs. Furthermore, this study identified the positive effect of increasing temperature on enhancing the stability of HMs in ash by transforming bioavailable HMs into non-bioavailable HMs, which decreased the leaching toxicity and environmental risk. Regarding HMs emissions control and cold gas efficiency, CO2 gasification treatment of tannery sludge is most effective at 800 °C.
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Affiliation(s)
- Yan Zhao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Cheng Zhang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
| | - Lun Ma
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Junchen Li
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Peng Tan
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Qingyan Fang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
| | - Gang Chen
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology, Wuhan 430074, China
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8
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Gao B, Jiang H, Zhang W, Peng M, Hu L, Mao L. Formation kinetics and reaction behavior of pentavalent chromium formed in the cement kiln co-processing of solid waste. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 904:166976. [PMID: 37704153 DOI: 10.1016/j.scitotenv.2023.166976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 08/29/2023] [Accepted: 09/08/2023] [Indexed: 09/15/2023]
Abstract
Cement kiln co-processing is becoming the main strategy to dispose of hazardous waste containing Cr. A newly-discovered pentavalent Cr compound, which was proved to be formed during cement kiln co-processing of solid waste, is partly responsible for the water-soluble Cr released from the cement. However, the formation characteristics and the solubility of Cr(V) are still unclear to date. In this study, the reaction kinetics and further redox reactions of Cr(V) at high temperature were examined, and its crystal structure and solubility were also explored. At the temperature range of 1000-1200 °C, the formation rate of Ca5(CrO4)3O0.5 reached over 90 % within 10 min, and then slowly increased to near 100 % from 10 min to 10 h. shows that Ca5(CrO4)3O0.5 is formed by interface reaction at an early period, and by diffusion at a later period. The kinetic analysis indicates that Ca5(CrO4)3O0.5 is initially formed through an interface reaction and subsequently through diffusion. Ca5(CrO4)3O0.5 was identified and assigned as hexagonal crystal group (P63/m). Approximately 0.55 g and 0.15 g of Ca5(CrO4)3O0.5 dissolve in neutral water at 100 °C and 50 °C, and the concentrations of Cr(V) in water reach 550 and 150 mg/L, respectively. Additionally, this study finds that at the temperature range of 400-700 °C Ca5(CrO4)3O0.5 can be oxidized into CaCrO4, and at the temperature higher than 1400 °C, it can be further converted into Ca3(CrO4)2 and reduced into CaCr2O4. This study gives a deep insight into Cr oxidation-reduction reaction during thermal treatment of solid waste. These insights provide a comprehensive understanding of Cr oxidation-reduction reactions during the thermal treatment of solid waste, offering valuable guidance for waste management strategies.
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Affiliation(s)
- Bingying Gao
- School of Petrochemical Engineering, Changzhou University, Changzhou 213164, China
| | - Haohao Jiang
- School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Wenyi Zhang
- School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Mingguo Peng
- School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Linchao Hu
- School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China
| | - Linqiang Mao
- School of Environmental Science and Engineering, Changzhou University, Changzhou 213164, China.
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9
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Lopez AM, Pacheco JL, Fendorf S. Metal toxin threat in wildland fires determined by geology and fire severity. Nat Commun 2023; 14:8007. [PMID: 38086795 PMCID: PMC10716285 DOI: 10.1038/s41467-023-43101-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Accepted: 10/31/2023] [Indexed: 12/18/2023] Open
Abstract
Accentuated by climate change, catastrophic wildfires are a growing, distributed global public health risk from inhalation of smoke and dust. Underrecognized, however, are the health threats arising from fire-altered toxic metals natural to soils and plants. Here, we demonstrate that high temperatures during California wildfires catalyzed widespread transformation of chromium to its carcinogenic form in soil and ash, as hexavalent chromium, particularly in areas with metal-rich geologies (e.g., serpentinite). In wildfire ash, we observed dangerous levels (327-13,100 µg kg-1) of reactive hexavalent chromium in wind-dispersible particulates. Relatively dry post-fire weather contributed to the persistence of elevated hexavalent chromium in surficial soil layers for up to ten months post-fire. The geographic distribution of metal-rich soils and fire incidents illustrate the broad global threat of wildfire smoke- and dust-born metals to populations. Our findings provide new insights into why wildfire smoke exposure appears to be more hazardous to humans than pollution from other sources.
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Affiliation(s)
- Alandra Marie Lopez
- Earth System Science Department, Stanford University, Stanford, CA, 94305, USA
| | - Juan Lezama Pacheco
- Earth System Science Department, Stanford University, Stanford, CA, 94305, USA
| | - Scott Fendorf
- Earth System Science Department, Stanford University, Stanford, CA, 94305, USA.
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10
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Yang Z, Ning Y, Wang C, Yang S, Zhang W, Dähn R, Li Y. The sensitive mobility of Cr in ashes studied by SiO 2-Al 2O 3-Fe 2O 3-CaO system. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 321:121091. [PMID: 36657511 DOI: 10.1016/j.envpol.2023.121091] [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: 06/19/2022] [Revised: 12/14/2022] [Accepted: 01/13/2023] [Indexed: 06/17/2023]
Abstract
Since incineration is a feasible method for stabilization/solidification of chromium (Cr)-enriched wastes, the species, distribution, and mobility of Cr in ashes deserve more studies, especially as the function of ash composition. Synthetic Cr-bearing ashes (SAs) were synthesized by SiO2-Al2O3-Fe2O3-CaO systems to investigate Cr mobility under 1100 °C. A study from simplicity to complexity. The Cr in SiO2-CaO is of high mobility with CrO42- formation, in contrary to the moderate mobility in SiO2-Al2O3 and poor mobility in SiO2-Fe2O3. However, species and mobility of Cr are affected by the values of CaO/SiO2, Al2O3/SiO2, and Fe2O3/SiO2 ratios. When other oxides are added to the two-phase systems above, the fate of Cr is affected more considerably. With the SiO2 content of 70%, adding a slight amount of CaO (<10%) strengthens the stabilization/solidification of Cr, due to the favorable solid integration under Ca2+ fusion. However, the Cr mobility is higher with increasing the CaO content further. The minimum content of CaO is ∼20% to sufficiently decrease the proportion of residual Cr (QCr-S5) in SiO2-Al2O3-CaO, much lower than in SiO2-Fe2O3-CaO, which confirms the easier release of Cr immobilized in Si-Al matrixes. Considering the opposite effects of Fe2O3 and CaO on Cr mobility, increasing Fe2O3/CaO ratios >3/2 can limit the effect of CaO, leading to the efficient stabilization/solidification of Cr waste. Additionally, the QCr-S5 is 83% with the Fe2O3 content of 15% in SiO2-Al2O3-Fe2O3, higher than in SiO2-Al2O3 and SiO2-Fe2O3. This suggests the intense stabilization/solidification of Cr, probably due to the formation of amorphous Fe-rich glass. Based on these above, an equation is developed to describe the relationship between ash compositions and QCr-S5 (QCr-S5 = -39.37X1 + 24.96X2 + 5.34X3 - 2.51X4 + 54.29).
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Affiliation(s)
- Zhe Yang
- School of Environmental Studies, China University of Geosciences, No. 68, Jincheng Street, Donghu New Technology Development Zone, Wuhan, 430074, PR China; Laboratory for Waste Management, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland
| | - Yu Ning
- School of Environmental Studies, China University of Geosciences, No. 68, Jincheng Street, Donghu New Technology Development Zone, Wuhan, 430074, PR China.
| | - Changxiang Wang
- School of Environmental Studies, China University of Geosciences, No. 68, Jincheng Street, Donghu New Technology Development Zone, Wuhan, 430074, PR China
| | - Sen Yang
- School of Environmental Studies, China University of Geosciences, No. 68, Jincheng Street, Donghu New Technology Development Zone, Wuhan, 430074, PR China; Guanghuiyuan Environment Water Co.Ltd., Shenzhen, 518011, China
| | - Wei Zhang
- School of Environmental Studies, China University of Geosciences, No. 68, Jincheng Street, Donghu New Technology Development Zone, Wuhan, 430074, PR China
| | - Rainer Dähn
- Laboratory for Waste Management, Paul Scherrer Institut, 5232, Villigen, PSI, Switzerland
| | - Yilian Li
- School of Environmental Studies, China University of Geosciences, No. 68, Jincheng Street, Donghu New Technology Development Zone, Wuhan, 430074, PR China
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11
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Hashem MA, Hasan M, Hasan MA, Sahen MS, Payel S, Mizan A, Nur-A-Tomal MS. Composting of limed fleshings generated in a tannery: sustainable waste management. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:39029-39041. [PMID: 36595172 DOI: 10.1007/s11356-022-25070-6] [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: 08/10/2022] [Accepted: 12/26/2022] [Indexed: 06/17/2023]
Abstract
In tanneries, limed fleshing is an unavoidable waste generated in beamhouse operation. Proper management of limed fleshing with protein, fat, lime, and sulfide will help to protect the natural environment and at least reduce the pollution that ends up in it. In this study, excluding any pretreatment, limed fleshing is used for compost production. Chopped and mixed limed fleshing with chicken manure, cow dung, and sawdust was heaped onto a horizontal bamboo frame. Three composting heaps were fabricated weighing 720, 700, and 760 kg. The turning of composting materials in the heaps causes temperature changes in the thermophilic range. The thermophilic temperatures in these heaps were 69.07 °C (heap 1), 69.9 °C (heap 2), and 69.19 °C (heap 3) which ensured the death of the pathogenic organism. The quality of compost was assessed based on the nutrients-nitrogen (N), phosphorous (P), potassium (K), and sulfur (S) content. NPKS in the compost fulfils the requirements of the investigated materials as compost. The largest amounts of metals- zinc (Zn), copper (Cu), chromium (Cr), lead (Pb), and nickel (Ni) of the compost detected in the heaps were, respectively, 200.3, 37.4, 20.3, 12.0, and 3.9 mg/kg. Cadmium (Cd) in the compost was below the detection limit. Scanning electron microscope (SEM) photographs show the decomposing of composting materials. This study indicates that limed fleshing can be converted into nutrient-enriched compost without any pretreatment. Using an easy, simple, and adaptable technique could reduce the volume of solid waste generated in the tannery to reduce environmental pollution.
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Affiliation(s)
- Md Abul Hashem
- Department of Leather Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh.
| | - Mehedi Hasan
- Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh
| | - Md Anik Hasan
- Department of Leather Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Md Sahariar Sahen
- Department of Leather Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Sofia Payel
- Department of Leather Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Al Mizan
- Department of Leather Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
| | - Md Shahruk Nur-A-Tomal
- Department of Leather Engineering, Khulna University of Engineering & Technology, Khulna, 9203, Bangladesh
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12
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Li J, Jia A, Hou X, Wang X, Mao Y, Wang W. Thermal co-treatment of aluminum dross and municipal solid waste incineration fly ash: Mineral transformation, crusting prevention, detoxification, and low-carbon cementitious material preparation. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2023; 329:117090. [PMID: 36584517 DOI: 10.1016/j.jenvman.2022.117090] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/15/2022] [Accepted: 12/18/2022] [Indexed: 06/17/2023]
Abstract
Harmless disposal and resource utilization of hazardous industrial wastes has become an important issue with the green development of human society. However, resource utilization of hazardous solid wastes, such as the production of cementitious materials, is usually accompanied by a pretreatment process to remove adverse impurities that contaminate the final product. In this study, aluminum dross (AD) was thermally co-treated with another hazardous waste, municipal solid incineration fly ash (MSWI-FA), to synergistically solidify F and Na, control leaching of heavy metals, and remove chloride impurities. Significant crusting was observed when AD was thermally treated by itself, but not when AD and MSWI-FA were thermally co-treated. In the process of co-thermal treatment, the remaining Cl, Na, and K contents were reduced to as low as 0.3%, 1.8%, and 0.6%, respectively. CaO and SiO2 in MSWI-FA reacted with Na3AlF6 and Al2O3 in AD, and formed CaF2 and Na6(AlSiO4)6, which contributed to the prevention of crusting and limited the leaching concentrations of F and Na to below detection thresholds and 270.6 mg/L, respectively. In addition, heavy metals were well solidified, and dioxins were fully decomposed during thermal treatment. Finally, a sulfoaluminate cementitious material (SACM) with high early- and later-age strengths was successfully created via synergetic complementarity using thermally co-treated AD and MSWI-FA together with other solid wastes. Collectively, this study outlines a promising method for the efficient and sustainable utilization of AD and MSWI-FA.
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Affiliation(s)
- Jingwei Li
- Shandong Engineering Laboratory for Solid Waste Green Materials, National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, 250014, China
| | - Aiguang Jia
- Shandong Engineering Laboratory for Solid Waste Green Materials, National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, 250014, China
| | - Xiangshan Hou
- Shandong Engineering Laboratory for Solid Waste Green Materials, National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, 250014, China
| | - Xujiang Wang
- Shandong Engineering Laboratory for Solid Waste Green Materials, National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, 250014, China.
| | - Yanpeng Mao
- Shandong Engineering Laboratory for Solid Waste Green Materials, National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, 250014, China
| | - Wenlong Wang
- Shandong Engineering Laboratory for Solid Waste Green Materials, National Engineering Laboratory for Reducing Emissions from Coal Combustion, Engineering Research Center of Environmental Thermal Technology of Ministry of Education, Shandong Key Laboratory of Energy Carbon Reduction and Resource Utilization, School of Energy and Power Engineering, Shandong University, Jinan, 250014, China
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13
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Lin K, Zhao Y, Kuo JH, Lin CL. Agglomeration-influenced transformation of heavy metals in gas-solid phases during simulated sewage sludge co-incineration: Effects of phosphorus and operating temperature. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 858:159759. [PMID: 36349628 DOI: 10.1016/j.scitotenv.2022.159759] [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: 05/07/2022] [Revised: 10/07/2022] [Accepted: 10/23/2022] [Indexed: 06/16/2023]
Abstract
Phosphorus and operating temperature not only affect the agglomeration behavior but also the transformation and migration of heavy metals. Accordingly, this study examined the effect of temperature and phosphorus in a fluidized bed combustion process to understand the emission and distribution of heavy metals by both experimental and thermodynamic calculations. The experimental results indicated that the sodium-phosphate reactions occur before the sodium-silicate reaction in the solid phase when the ratio of P/Na was 1/2. A low-melting-point sodium phosphate component, such as NaPO3, leads to easier particle agglomeration than Na2O-SiO2. In terms of the emissions of heavy metals, Pb and Cd show a similar trend: both the amount of emission smaller than that without adding phosphorus and the amount of emission share an upward trend with the operating time increased during MSS fluidized bed combustion. However, with the presence of phosphorus, the emission of Cr shows slightly decreased, and then sharply dropped, after that, increasing with operating time increased. Generally speaking, the maximum amount of Pb and Cd emitted was at 900 °C, followed by 800 °C and 700 °C. The higher temperature would promote the volatilization of Pb and Cd to emit. On the other hand, Cr emitted at the beginning tended to increase but later decreases when the temperatures were 700 and 900 °C, which may be due to the emission of Cr being influenced by the different affinities of both Al and Cr, reacting with Na in a fluidized bed incinerator. As for the distribution of heavy metals in the solid phase, a higher concentration of heavy metals was found in both the coarsest and finest particles during the process of agglomeration/defluidization.
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Affiliation(s)
- Kunsen Lin
- The State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Youcai Zhao
- The State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, 1239 Siping Road, Shanghai 200092, China
| | - Jia-Hong Kuo
- Department of Safety, Health and Environmental Engineering, National United University, 36063 Miaoli, Taiwan.
| | - Chiou-Liang Lin
- Department of Civil and Environmental Engineering, National University of Kaohsiung, 81148 Kaohsiung, Taiwan
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14
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Tang Q, Zhang H, Zhao X, Miao C, Yang P, Zhou Z, Ji Q, Chen L. Speciation, bioaccessibility and human health risk assessment of chromium in solid wastes from an ultra-low emission coal-fired power plant, China. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2022; 315:120400. [PMID: 36228856 DOI: 10.1016/j.envpol.2022.120400] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/17/2022] [Revised: 09/16/2022] [Accepted: 10/05/2022] [Indexed: 06/16/2023]
Abstract
Chromium (Cr) in solid wastes from ultra-low emission (ULE) coal-fired power plants (CFPPs) could engender adverse effects on environment and human health. Hence, solid waste samples containing bottom ash, fly ash, gypsum and sludge were collected from a typical ULE CFPP in China to study the distribution, speciation, bioaccessibility and human health risk of Cr. The results showed that Cr was depleted in gypsum, whereas significantly enriched in bottom ash, fly ash and sludge comparing with feed coal. The ratios of Cr(VI) to total Cr in solid wastes were relatively low, but the increase of flow fractions in Cr chemical binding forms implied the deterioration of environmental stability. Based on the in vitro simulated digestion methods of solubility bioavailability research consortium (SBRC) and physiologically based extraction test (PBET), the bioaccessibility of Cr in the gastric and intestinal phases reached the highest values in either gypsum or sludge. After incorporating bioaccessibility in human health risk assessment, the carcinogenic risk (CR) within acceptable limits of Cr in solid wastes to adults and children was concluded, with the non-carcinogenic hazard quotient (HQ) was all within the safety threshold. The Monte Carlo model was applied to evaluate the uncertainty analysis of human health risk assessment at 5% and 95% confidence interval, and the fitting results were consistent with the calculation results of the carcinogenic and non-carcinogenic risk for adults and children. This study is expected to provide insights for the integration of bioaccessibility into the health risk assessment of Cr in solid wastes from ULE CFPPs, thus is conducive to the disposal of solid wastes and human health protection.
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Affiliation(s)
- Quan Tang
- School of Life Sciences, Anhui University, Hefei, 230601, China.
| | - Huiming Zhang
- School of Life Sciences, Anhui University, Hefei, 230601, China
| | - Xiaohu Zhao
- School of Life Sciences, Anhui University, Hefei, 230601, China
| | - Chunhui Miao
- Anhui Xinli Power Technology Consulting Company with Limited Liability, State Grid Anhui Electric Power Corporation Research Institute, Hefei, 230601, China
| | - Pengpeng Yang
- School of Life Sciences, Anhui University, Hefei, 230601, China
| | - Zhongkang Zhou
- Anhui Xinli Power Technology Consulting Company with Limited Liability, State Grid Anhui Electric Power Corporation Research Institute, Hefei, 230601, China
| | - Qiaozhen Ji
- Anhui Xinli Power Technology Consulting Company with Limited Liability, State Grid Anhui Electric Power Corporation Research Institute, Hefei, 230601, China
| | - Lai Chen
- School of Business, Anhui University, Hefei, 230601, China
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15
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Yang L, Wang L, Cui C, Long H, Huang X, Liu M, Li L, Xu S, Wang M, Yan D. Heavy metal and metalloid emissions during co-processing of waste in a sintering kiln: Migration characteristics in the kiln and long-term leaching from bricks. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 322:116145. [PMID: 36070648 DOI: 10.1016/j.jenvman.2022.116145] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 08/01/2022] [Accepted: 08/28/2022] [Indexed: 06/15/2023]
Abstract
Heavy metals (HMs) in mixed hazardous waste can be volatilized in the kiln for preparing sintered bricks, which greatly increases the environmental risk. In this study, the volatilization, transformation, and leaching of HMs from bricks were evaluated. Field tests and laboratory leaching experiments were carried out. HM-contaminated soil was used to prepare sintered bricks at high-temperature in a tunnel kiln. Release of HMs from brick under rainfall conditions was investigated in laboratory simulation experiments. The field tests showed that the total amount of Pb, Zn, Cd distributed to the gas phase were all less than 2%, but the amount of Hg entering the gas phase 40.1%-60.5% in the particulate forms. The As leaching rate increased after sintering of bricks in the kiln, which was attributed to the increased formation of soluble arsenate and the reduced availability of sorption sites. The tank leaching test indicated that the release mechanism of trance elements (Cr, As, Zn, Cd, Pb and Ni) was mainly controlled by diffusion. This study provides useful knowledge for decreasing the volatilization and leaching of HMs from sintered bricks prepared using hazardous waste.
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Affiliation(s)
- Liuyang Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Lei Wang
- School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
| | - Changhao Cui
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Hua Long
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Xinyu Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; School of Environmental Science and Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Meijia Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Li Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Siqi Xu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China
| | - Mingwei Wang
- School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing 102206, China
| | - Dahai Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
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16
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Li Y, Huang Y, Li Z, Tang X, Liu X, Hughes SS. Mechanisms of chromium isotope fractionation and the applications in the environment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2022; 242:113948. [PMID: 35999763 DOI: 10.1016/j.ecoenv.2022.113948] [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: 03/01/2022] [Revised: 07/31/2022] [Accepted: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Chromium (Cr) is a toxic heavy metal that gives rise to environmental pollution and human risk. Chromium stable isotopes have a wide range of applications in both environmental field and earth science field. In this contribution, we focus on the application of the Cr isotope in both tracing pollution sources and monitoring Cr(Ⅵ) pollution. Meanwhile, we also provide a description of the main influencing factors controlling Cr isotope fractionation, chromium isotope analytical methods, and terrestrial Cr release. Chromium isotope tracing of contaminant sources is a new application method, it has a tremendous advantage in searching for the source of Cr pollution, which has not been covered in previous reviews. At the end of the article, the current status of Cr isotope applications in the paleo-environment is explained. Although there are still some uncertainties in practical applications, chromium isotope system shows great promise in the environmental aspects.
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Affiliation(s)
- Ying Li
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Yi Huang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China; State Key Laboratory of Collaborative Control and Joint Remediation of Soil and Water Pollution, College of Ecology and Environment, Chengdu University of Technology, Chengdu 610059, Sichuan, China.
| | - Zijing Li
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Xue Tang
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Xiaowen Liu
- State Key Laboratory of Geohazard Prevention and Geoenvironment Protection, College of Geosciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China
| | - Scott S Hughes
- Department of Geosciences, Idaho State University, Pocatello, ID 83209, USA
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17
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Huang K, Wang L, Wen Y, He K, Zhang M, Du J, Hu X. Oxidation leaching of chromium from electroplating sludge: Ultrasonic enhancement and its mechanism. Front Chem 2022; 10:958773. [PMID: 36092662 PMCID: PMC9453026 DOI: 10.3389/fchem.2022.958773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2022] [Accepted: 08/01/2022] [Indexed: 11/15/2022] Open
Abstract
The oxidation leaching of chromium from electroplating sludge was investigated, and ultrasonication was introduced for the enhancement of the leaching process. Two different types of Cr-bearing electroplating sludge were selected for the study, and the effects of the reagent dosage, temperature, and ultrasonic pulse ratio on the leaching efficiency were tested through oxidation leaching experiments. The experimental results show that hydrogen peroxide and sodium hypochlorite exhibit different leaching effects on different types of electroplating sludge. The control of reagent dosage is crucial for the oxidation leaching of Cr, while the effect of temperature turns out to be small. Hydrogen peroxide turns out to be a more effective oxidizer for chromium sludge, and the leaching efficiency of Cr could be promoted from 77.52% to 87.08% using ultrasonic enhancement under optimum conditions. Interestingly, sodium hypochlorite exhibited better leaching efficiency than hydrogen peroxide for the mixed sludge since the organic matter in the mixed sludge will lead to the rapid decomposition and consumption of hydrogen peroxide. The leaching efficiency of Cr from the mixed sludge could also be promoted from 56.82% to 67.10% using ultrasonic enhancement under optimum conditions. According to the scanning electron microscope imaging, ultrasonic enhancement can create voids and cracks on the surface of the sludge particles, hence promoting the contact between electroplating sludge and leaching agents, and promoting the oxidation leaching efficiency. In addition, ultrasound seems to be able to remove the coverings on the surface of the mixed sludge particles, which may facilitate the oxidation reaction.
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Affiliation(s)
- Kaihua Huang
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
| | - Lizhangzheng Wang
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
- School of Resources and Environmental Engineering, Wuhan University of Technology, Wuhan, China
| | - Yong Wen
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
| | - Kuang He
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
| | - Mingyang Zhang
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
| | - Jianwei Du
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
- *Correspondence: Jianwei Du, ; Xiaoying Hu,
| | - Xiaoying Hu
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou, China
- *Correspondence: Jianwei Du, ; Xiaoying Hu,
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18
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Rascio I, Allegretta I, Gattullo CE, Porfido C, Suranna GP, Grisorio R, Spiers KM, Falkenberg G, Terzano R. Evidence of hexavalent chromium formation and changes of Cr speciation after laboratory-simulated fires of composted tannery sludges long-term amended agricultural soils. JOURNAL OF HAZARDOUS MATERIALS 2022; 436:129117. [PMID: 35594675 DOI: 10.1016/j.jhazmat.2022.129117] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 04/12/2022] [Accepted: 05/06/2022] [Indexed: 06/15/2023]
Abstract
Controlled or accidental fires can impact agricultural soils amended with composted organic materials since high temperatures cause fast organic matter (OM) mineralization and soil properties modifications. During these events, potentially toxic elements (PTEs) associated with OM can be released and change their distribution and speciation thus becoming a threat to the environment and to crops. In this study, we investigated the changes of distribution and speciation of chromium in soils long-term amended with compost obtained from tannery sludges, after simulating fires of different intensity (300, 400 and 500 °C) likely to occur on agricultural soils. A combination of conventional soil chemical analyses and bulk and (sub)micro X-ray analyses allowed the observation of the formation of hexavalent chromium and changes of chromium speciation. Specifically, a strong decrease of Cr-OM associations was found with increasing temperature in favour of Cr-iron (hydr)oxides interactions and CaCrO4 formation. These data provide first evidence that fires can transform OM-stabilized Cr into more mobile, available and toxic Cr-forms potentially accessible for plant uptake, thus posing a risk for the food chain and the environment.
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Affiliation(s)
- Ida Rascio
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via G. Amendola 165/A, 70126 Bari, Italy
| | - Ignazio Allegretta
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via G. Amendola 165/A, 70126 Bari, Italy
| | - Concetta Eliana Gattullo
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via G. Amendola 165/A, 70126 Bari, Italy
| | - Carlo Porfido
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via G. Amendola 165/A, 70126 Bari, Italy
| | - Gian Paolo Suranna
- Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, Via Orabona 4, 70125 Bari, Italy; CNR NANOTEC - Istituto di Nanotecnologia, Via Monteroni, 73100 Lecce, Italy
| | - Roberto Grisorio
- Dipartimento di Ingegneria Civile, Ambientale, del Territorio, Edile e di Chimica (DICATECh), Politecnico di Bari, Via Orabona 4, 70125 Bari, Italy; CNR NANOTEC - Istituto di Nanotecnologia, Via Monteroni, 73100 Lecce, Italy
| | - Kathryn M Spiers
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Gerald Falkenberg
- Deutsches Elektronen-Synchrotron DESY, Notkestr. 85, 22607 Hamburg, Germany
| | - Roberto Terzano
- Department of Soil, Plant and Food Sciences, University of Bari "Aldo Moro", Via G. Amendola 165/A, 70126 Bari, Italy.
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19
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Zhang W, Wu Y, Huang S, Wu S, Gao J. Study on physicochemical characteristics, solidification and utilisation of tannery sludge gasification ash. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 310:114584. [PMID: 35192982 DOI: 10.1016/j.jenvman.2022.114584] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/19/2022] [Accepted: 01/20/2022] [Indexed: 06/14/2023]
Abstract
Gasification is an attractive method for tannery sludge (TS) disposal because of its advantages: volume reduction, stabilisation, harmlessness, and energy recovery. TS reduction ash (AR) and TS oxidation ash (AO), simulated from a downdraft fixed bed gasifier (DFBG) and an updraft fixed bed gasifier (UFBG), were investigated on their physicochemical characteristics, solidification behaviour, and value-added utilisation. Results showed that the main mineral matters in AR and AO consisted of Fe-oxids and Fe-Cr compounds, and the DFBG was more suitable for TS gasification than the UFBG because of the lower content of Cr(Ⅵ) in AR. With the addition of waste glass bottles (WGB), the ash fusion temperatures (AFTs) and leaching concentrations of heavy metals in AR and AO decreased significantly, and the heavy metals in AR and AO were successfully immobilised by the wrapping effect of the molten WGB. Moreover, gasification ash, as an auxiliary material for rock wool, reduced the AFTs and viscosity coefficient of the main chemical compositions in rock wool. With the addition of AR, the occurrence of Fe-containing compounds and the extremely low risk of leaching toxicity of heavy metals were observed. The maximum addition proportion of gasification ash was dependent on the maximum content of Fe2O3 allowed in the raw materials of rock wool, and its addition ratio must be below 15%.
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Affiliation(s)
- Weiwei Zhang
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, Shanghai, 200237, China
| | - Youqing Wu
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Coal Gasification, East China University of Science and Technology, Shanghai, 200237, China.
| | - Sheng Huang
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Coal Gasification, East China University of Science and Technology, Shanghai, 200237, China
| | - Shiyong Wu
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Coal Gasification, East China University of Science and Technology, Shanghai, 200237, China
| | - Jinsheng Gao
- Department of Chemical Engineering for Energy Resources, East China University of Science and Technology, Shanghai, 200237, China; Shanghai Engineering Research Center of Coal Gasification, East China University of Science and Technology, Shanghai, 200237, China
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20
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Zou H, Huang S, Ren M, Liu J, Evrendilek F, Xie W, Zhang G. Efficiency, by-product valorization, and pollution control of co-pyrolysis of textile dyeing sludge and waste solid adsorbents: Their atmosphere, temperature, and blend ratio dependencies. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 819:152923. [PMID: 34999078 DOI: 10.1016/j.scitotenv.2022.152923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/31/2021] [Accepted: 01/01/2022] [Indexed: 06/14/2023]
Abstract
This study aimed to quantify the co-pyrolytic synergistic effects of textile dyeing sludge (TDS) and waste biochar (WBC) for an optimal utilization of secondary resources and to mitigate environmental pollution and waste volume. TDS and WBC had a strong synergistic effect between 800 and 900 °C in the CO2-assisted atmosphere. With the increased TDS fraction, NH3 emission fell significantly regardless of the atmosphere type. The CO2 atmosphere changed S in TDS char and released SO2 in the range of 800-1000 °C. With the temperature rise, an unstable N structure turned into a more stable heterocyclic N structure in the CO2 and N2 atmospheres. Regardless of the atmosphere type and temperature, the C-containing functional groups in co-pyrolytic biochar existed mainly as C-C/C-H. In the CO2 atmosphere, inorganic S, aliphatic S, and thiophene S in the co-pyrolytic biochar disappeared and became more stable sulfones. The co-pyrolysis inhibited the formation of S-containing compounds. The retention ability of the co-pyrolytic biochar peaked for most of the heavy metals in the N2 atmosphere but was better for Pb and Zn in the CO2 than N2 atmosphere. Simultaneous optimization showed the co-pyrolysis of 10% TDS and 90% WBC at above 950 °C in the N2-CO2 or CO2 atmosphere as the optimal operational settings combined.
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Affiliation(s)
- Huihuang Zou
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Shengzheng Huang
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Mingzhong Ren
- South China Institute of Environmental Sciences, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Jingyong Liu
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China.
| | - Fatih Evrendilek
- Department of Environmental Engineering, Bolu Abant Izzet Baysal University, Bolu 14052, Turkey
| | - Wuming Xie
- School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006, China
| | - Gang Zhang
- Engineering Research Center of None-food Biomass Efficient Pyrolysis and Utilization Technology of Guangdong Higher Education Institutes, Dongguan University of Technology, Dongguan 523808, China
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21
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Shi F, Jiang D, Ji J, Yan J, Chen H. Effects of Alkali on Water Soluble Hexavalent Chromium in Ordinary Portland Cement. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19084811. [PMID: 35457677 PMCID: PMC9025607 DOI: 10.3390/ijerph19084811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 04/13/2022] [Accepted: 04/14/2022] [Indexed: 11/26/2022]
Abstract
Due to the toxicity and mobility of chromium, the disposal of chromium-containing waste is a pressing issue. Co-processing of chromium-containing waste in a cement kiln is currently one of the most effective methods. However, the presence of water-soluble hexavalent chromium (Cr(VI)) in cement limits the use of this method. In this study, Na2CO3 was used to simulate alkali in industrial raw materials to investigate the pattern of influence of alkali content on water-soluble hexavalent chromium. The mechanisms associated with the oxidation and dissolution of chromium were investigated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma emission spectrometry (ICP-OES). The proportion of Cr(VI) in the clinker detected by XPS increased rapidly with increasing alkali content. In the cement slurry system, alkali promotes more hexavalent chromium leaching by influencing pH and other ion concentrations (Ca2+, SO42−). Therefore, the addition of alkali to either the raw meal or to the cement slurry system will favour an increase in the water-soluble Cr(VI) content. This study may provide theoretical guidance for the preparation and use of clinkers containing chromium.
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Affiliation(s)
- Fan Shi
- School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China;
| | - Dehong Jiang
- Chongzuo South Cement Co., Ltd., Chongzuo 532200, China; (D.J.); (J.J.); (J.Y.)
| | - Junrong Ji
- Chongzuo South Cement Co., Ltd., Chongzuo 532200, China; (D.J.); (J.J.); (J.Y.)
| | - Jinsheng Yan
- Chongzuo South Cement Co., Ltd., Chongzuo 532200, China; (D.J.); (J.J.); (J.Y.)
| | - Huxing Chen
- School of Materials Science and Engineering, Zhejiang University, Hangzhou 310027, China;
- Correspondence:
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22
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Long H, Huang X, Liu M, Cui C, Li L, Liao Y, Yan D. The fate of heavy metals in the co-processing of solid waste in converter steelmaking. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 311:114877. [PMID: 35279489 DOI: 10.1016/j.jenvman.2022.114877] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 02/26/2022] [Accepted: 03/07/2022] [Indexed: 06/14/2023]
Abstract
The improper disposal of large amounts of solid waste (SW) has led to serious ecological and environmental problems, especially heavy metal (HM) pollution. Converter steelmaking has the potential to co-process SW, but the distribution of heavy metals (HMs) during converter steelmaking is unclear. In this study, the effects of smelting temperature and slag alkalinity on the distribution of typical HMs in the SW of steel samples, steel slag, and the gas phase were investigated in a specially-made induction furnace. The results showed that upon increasing the smelting temperature, As (As2S3) was mainly distributed in the steel sample, and the HM-containing compounds Cr2O3, CrCl3, ZnCl2, ZnS, ZnO, PbCl2, PbS, and PbO were mainly distributed in the gas phase. Upon increasing the alkalinity within a certain range, the distribution of HMs in steel samples and steel slag increased gradually, while their distribution in the gas phase decreased. Thermodynamic calculations, Eh-pH diagrams, XRD patterns, and XPS spectra indicated that impurity elements in the hot metal and the CaO content affected the chemical reactions by which HM-containing compounds in the steel sample formed elemental HMs and those in steel slag existed as oxides; therefore, it is necessary to choose a suitable temperature and alkalinity for slag when disposing of different types of SW.
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Affiliation(s)
- Hua Long
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China; College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China; Beijing SPC Environment Protection Tech Co, Ltd, Beiing, 100142, China
| | - Xinyu Huang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Meijia Liu
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Changhao Cui
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Li Li
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China
| | - Yang Liao
- College of Chemistry and Materials Science, Sichuan Normal University, Chengdu, 610068, China.
| | - Dahai Yan
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing, 100012, China.
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23
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Jiang H, Wang J, Zhang W, Hu L, Mao L. Oxidation and reduction reactions of (Al/Fe xCr 1-x) 2O 3 caused by CaO during thermal treatment of solid waste containing Cr. ENVIRONMENTAL RESEARCH 2022; 204:112356. [PMID: 34822857 DOI: 10.1016/j.envres.2021.112356] [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: 07/29/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 06/13/2023]
Abstract
Solid solutions of (AlxCr1-x)2O3 and (FexCr1-x)2O3 are predominant compounds containing Cr in solid waste and are frequently formed during thermal treatment of solid waste. (AlxCr1-x)2O3 and (FexCr1-x)2O3 have superior thermomechanical properties and excellent corrosion resistance. However, oxidation and reduction reactions of the Cr in these solid solutions seriously affect their chemical stabilities and the environmental risks posed by the final products. In this study, first the reaction behaviors of (AlxCr1-x)2O3 and (FexCr1-x)2O3 at high temperatures were analyzed and whether the incorporation of Cr(III) in solid solutions can prevent Cr(III) from being oxidized was determined. Both (AlxCr1-x)2O3 and (FexCr1-x)2O3 without the presence of CaO exhibit good thermal stability at high temperatures. However, the participation of CaO induces Cr(III) oxidation in (AlxCr1-x)2O3 and (FexCr1-x)2O3 at 500-1000 °C. Cr(III) oxidation in these solid solutions is accompanied by the formation of CaCrO4 and Fe2O3 or Al2O3. Al2O3 combines with CaCrO4 and further forms a more stable Cr(VI) compound (e.g., Ca4Al6O12CrO4). While Fe2O3 combines with CaCrO4 at 1000-1200 °C. This is accompanied by the formation of CaCr2O4 and CaFe2O4, which effectively promotes the reduction of Cr(VI). Moreover, part of the CaCr2O4 transforms into a more stable phase (i.e., FeCr2O4) at 1200-1300 °C. Although the incorporation of Cr(III) in these solid solutions cannot prevent Cr(III) oxidation completely at high temperatures, the Cr(III) oxidation in these solid solutions is still suppressed compared with Cr2O3. The results of this study provide further insights into the oxidation and reduction reactions of Cr-hosting compounds during thermal treatment of solid waste.
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Affiliation(s)
- Haohao Jiang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Jia Wang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Wenyi Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Linchao Hu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Linqiang Mao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China.
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24
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Liu X, Jiang H, Wang J, Zhang W, Hu L, Peng M, Mao L. Oxidation reaction behavior of Cr-hosting spinels during heating of solid wastes containing Cr. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 800:149634. [PMID: 34426319 DOI: 10.1016/j.scitotenv.2021.149634] [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: 04/29/2021] [Revised: 07/28/2021] [Accepted: 08/09/2021] [Indexed: 06/13/2023]
Abstract
Cr-hosting spinels are frequently formed during heating of solid wastes containing multiple metals, and its oxidation reaction (Cr(III) → Cr(VI)) is closely related with the toxicity of products. This study examined the reaction behaviors of Cr-hosting spinels (ZnCr2O4, CuCr2O4 and NiCr2O4) at high temperature and proposed possible oxidation mechanism. Cr-hosting spinels alone usually exhibit good thermal stability at high temperature. However, CaO can trigger the oxidation of Cr(III) in Cr-hosting spinels at 500-900 °C and ZnCr2O4 is easier to be oxidized than NiCr2O4 and CuCr2O4 at same condition. The oxidation of Cr-hosting spinels is accompanied with the formation of CaCrO4 and divalent metal oxides (ZnO, NiO and CuO). The broken and rebuilding of CrO bonds are key steps for Cr-hosting spinels oxidation, blocking the combination of free Cr with Ca and O atoms maybe more effective approach for suppressing Cr(III) oxidation. Furthermore, CaO can trigger the reduction of CaCrO4 into a new Cr(V) compound (Ca5(CrO4)3O0.5) at 900-1200 °C. As the temperature rising to 1300 °C, CuO reacts with CaCrO4 to form CuCrO2, in which Cu(II) and Cr(VI) are reduced into Cu(I) and Cr(III) respectively. This study provided some new knowledge for the reaction behavior of Cr-hosting spinels when solid wastes containing Cr were treated at high temperature.
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Affiliation(s)
- Xiao Liu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China
| | - Haohao Jiang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China
| | - Jia Wang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China
| | - Wenyi Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China
| | - Linchao Hu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China
| | - Mingguo Peng
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China
| | - Linqiang Mao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China.
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25
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High-Temperature Chemical Stability of Cr(III) Oxide Refractories in the Presence of Calcium Aluminate Cement. MATERIALS 2021; 14:ma14216590. [PMID: 34772112 PMCID: PMC8585193 DOI: 10.3390/ma14216590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/21/2021] [Accepted: 10/26/2021] [Indexed: 11/20/2022]
Abstract
Al2O3-CaO-Cr2O3 castables are used in various furnaces due to excellent corrosion resistance and sufficient early strength, but toxic Cr(VI) generation during service remains a concern. Here, we investigated the relative reactivity of analogous Cr(III) phases such as Cr2O3, (Al1−xCrx)2O3 and in situ Cr(III) solid solution with the calcium aluminate cement under an oxidizing atmosphere at various temperatures. The aim is to comprehend the relative Cr(VI) generation in the low-cement castables (Al2O3-CaO-Cr2O3-O2 system) and achieve an environment-friendly application. The solid-state reactions and Cr(VI) formation were investigated using powder XRD, SEM, and leaching tests. Compared to Cr2O3, the stability of (Al1−xCrx)2O3 against CAC was much higher, which improved gradually with the concentration of Al2O3 in (Al1−xCrx)2O3. The substitution of Cr2O3 with (Al1−xCrx)2O3 in the Al2O3-CaO-Cr2O3 castables could completely inhibit the formation of Cr(VI) compound CaCrO4 at 500–1100 °C and could drastically suppress Ca4Al6CrO16 generation at 900 to 1300 °C. The Cr(VI) reduction amounting up to 98.1% could be achieved by replacing Cr2O3 with (Al1−xCrx)2O3 solid solution. However, in situ stabilized Cr(III) phases as a mixture of (Al1−xCrx)2O3 and Ca(Al12−xCrx)O19 solid solution hardly reveal any reoxidation. Moreover, the CA6 was much more stable than CA and CA2, and it did not participate in any chemical reaction with (Al1−xCrx)2O3 solid solution.
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26
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El-Hasan T, Harfouche M, Aldrabee A, Abdelhadi N, Abu-Jaber N, Aquilanti G. Synchrotron XANES and EXAFS evidences for Cr +6 and V +5 reduction within the oil shale ashes through mixing with natural additives and hydration process. Heliyon 2021; 7:e06769. [PMID: 33937543 PMCID: PMC8079444 DOI: 10.1016/j.heliyon.2021.e06769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2021] [Revised: 03/07/2021] [Accepted: 04/07/2021] [Indexed: 12/04/2022] Open
Abstract
Solid friable residues (i.e. Ash) from combusted oil shale are a major environmental issue because they are highly enriched with toxic elements following combustion. The synchrotron based techniques X-ray Absorption Fine Structure (XAFS) were used for determining the changes in speciation of Chromium (Cr) and Vanadium (V) in the ash and its mixtures with Red soil and Phosphogypsum as additives, through one-year period of hydration process. The X-ray Absorption Near Edge Structure (XANES) qualitative results indicate that all mixtures exhibits similar patterns showing that Vanadium has remain as pentavalent state, on the contrary Chromium has dramatic decreased from hexavalent to trivalent. This change in Cr speciation became clearer with increasing hydration period. Therefore, the results confirmed the advantage of the hydration process in the Cr(VI) reduction which might be due the domination of carbonate phase within all mixtures, thus hydration caused carbonate dissolution that increase the pH toward more alkaline which caused the Cr(IV) reduction into less-harmful and less mobile Cr(III). This increase in pH was not in favor of changing the V(V) into V(IV) due to its large stability field V(V). The Extend X-ray Absorption Fine Structure (EXAFS) analysis showed that Cr exhibiting a coordination shell of C-atoms as first nearest neighbors backscattering atoms around Cr, and at C-atoms backscattering at medium range order. This confirmed the domination of carbonate media through the best fitting of Cr–C. Which might be attributed to the more alkaline conditions developed during saturation of water (hydration), that accelerates of the reduction of Cr(VI) into Cr(III). This means simply that hydration of the ash can reduce the presence of harmful Cr(VI) in these ash tailings.
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Affiliation(s)
- Tayel El-Hasan
- Department of Chemistry, Mutah University, 61710, Mutah, Jordan
| | | | | | - Nafeth Abdelhadi
- Faculty of Engineering and Technology, Al-Balqa Technical University, Amman, Jordan
| | - Nizar Abu-Jaber
- Dept. of Civil and Environmental Engineering, German Jordanian University, Naour, Jordan
| | - Giuliana Aquilanti
- Elettra - Sincrotrone Trieste, Area Science Park, 34149 Basovizza, Trieste, Italy
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27
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Combination of Thermal, Hydrometallurgical and Electrochemical Tannery Waste Treatment for Cr(III) Recovery. APPLIED SCIENCES-BASEL 2021. [DOI: 10.3390/app11020532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A combination of thermal (500–750 °C in air) and hydrometallurgical (acidic) treatments have been applied to dried tannery sludge, resulting in the initial conversion of Cr(III) to Cr(VI) and its subsequent leaching as wastewater with high Cr(VI) concentration content (3000–6000 mg/L), presenting an extraction efficiency over 90%. The optimal electrochemical conditions for the subsequent Cr(VI) reduction with respect to acid concentration and acid kind were established by applying appropriate rotating disc electrode (RDE) experiments, using a glassy carbon (GC) electrode, and found to be equal or higher than 0.5 M H2SO4 (for the respective Cr(III) concentration range studied). The result from leaching Cr(VI) wastewater was further treated in small electrochemical bench-scale reactor for its conversion back to Cr(III) form, potentially reusable in the tanning industry. Ti-based anodes and a reticulated vitreous carbon (RVC) cathode were used to treat small (350–800 mL) samples in batch, as well as in batch-recirculation prototype electrochemical reactors, under the application of constant current or appropriately applied potential to achieve Cr(VI) conversion/reduction efficiency over 95%.
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28
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Gujre N, Mitra S, Soni A, Agnihotri R, Rangan L, Rene ER, Sharma MP. Speciation, contamination, ecological and human health risks assessment of heavy metals in soils dumped with municipal solid wastes. CHEMOSPHERE 2021; 262:128013. [PMID: 33182094 DOI: 10.1016/j.chemosphere.2020.128013] [Citation(s) in RCA: 71] [Impact Index Per Article: 23.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Revised: 08/03/2020] [Accepted: 08/12/2020] [Indexed: 05/24/2023]
Abstract
The main aim of this work is to assess the extent of soil contamination, potential ecological and health risks associated with the disposal of municipal solid waste (MSW) near a Ramsar site in Assam, India. Soil samples were collected and analysed for three heavy metals (HMs), namely, chromium (Cr), manganese (Mn) and zinc (Zn). The sources of HMs and their pollution levels were evaluated using different indices. The results demonstrated that Cr contamination was high near the metal scrap segregations unit within the dumping site, otherwise, the ecological risks associated with Zn and Mn were found to be low. The speciation of Cr and Zn were associated with the Fe-Mn oxide bound (F4) fraction, accounting 44.23% and 30.68%, respectively, whereas Mn (52.55%) was associated with the exchangeable fraction (F2). The fate and origin of HMs were assessed using mobility and enrichment factors and 16 out of the 20 sampling sites fell under the category of heavily polluted category for Cr, while others which were nearby the metal segregation units fell under the strongly to extremely polluted category. In few sites, significant enrichment was observed for Zn and minimal to moderate enrichment for Mn, respectively. Health risk assessment results indicated that Cr posed higher threat to human health through ingestion.
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Affiliation(s)
- Nihal Gujre
- Agro-ecotechnology Laboratory, Centre for Rural Technology, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India
| | - Sudip Mitra
- Agro-ecotechnology Laboratory, Centre for Rural Technology, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India.
| | - Ankit Soni
- Agro-ecotechnology Laboratory, Centre for Rural Technology, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India
| | - Richa Agnihotri
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, Madhya Pradesh 452001, India
| | - Latha Rangan
- Agro-ecotechnology Laboratory, Centre for Rural Technology, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India; Department of Biosciences and Bioengineering, Indian Institute of Technology Guwahati (IITG), Guwahati, Assam 781039, India
| | - Eldon R Rene
- Department of Environmental Engineering and Water Technology, IHE Delft Institute for Water Education, 2601 DA Delft, the Netherlands
| | - Mahaveer P Sharma
- ICAR-Indian Institute of Soybean Research, Khandwa Road, Indore, Madhya Pradesh 452001, India
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29
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Mao L, Wang J, Zeng M, Zhang W, Hu L, Peng M. Temperature dependent reduction of Cr(VI) to Cr(V) aroused by CaO during thermal treatment of solid waste containing Cr(VI). CHEMOSPHERE 2021; 262:127924. [PMID: 32805661 DOI: 10.1016/j.chemosphere.2020.127924] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/31/2020] [Accepted: 08/03/2020] [Indexed: 06/11/2023]
Abstract
Cr(VI) compounds at high temperature usually tend to decompose and reduce into Cr(III) due to thermodynamically instability for Cr(VI). This study found Cr(VI) could be reduced into Cr(V) instead of Cr(III) in the presence of CaO during heating solid waste containing Cr(VI). CaCrO4 is prepared and mixed with CaO as simulated solid waste containing Cr(VI). It was found that CaCrO4 reacted with CaO and formed a new product Ca5(CrO4)3O0.5 at temperature range of 800 and 1000 °C. The valence state of Cr in Ca5(CrO4)3O0.5 is determined to be +5 b y XPS analysis, and the color for new formed Cr(V) is observed in green, similar to Cr(III) compounds. The temperature and CaO are two keys to arouse the reduction reaction of Cr(VI) into Cr(V). In particular, the reduction of Cr(VI) into Cr(V) is strongly depended on temperature (800-1000 °C), this reaction can be balanced within 10 min, while prolonging sintering time has little help for promoting the reduction of Cr(VI) to Cr(V). Additionally, it was found Cr(V) can keep stable and not be re-oxidized into Cr(VI) at 800-1000 °C. Above results offers some new understanding and knowledge about the formation of Cr(V) in presence of much CaO or CaCO3 during heating solid waste containing Cr(VI).
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Affiliation(s)
- Linqiang Mao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China.
| | - Jia Wang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Man Zeng
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Wenyi Zhang
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China.
| | - Linchao Hu
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
| | - Mingguo Peng
- School of Environmental and Safety Engineering, Changzhou University, Changzhou, 213164, PR China
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30
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Lane DJ, Sippula O, Peräniemi S, Jokiniemi J. Detoxification of wood-combustion ashes containing Cr and Cd by thermal treatment. JOURNAL OF HAZARDOUS MATERIALS 2020; 400:123315. [PMID: 32947715 DOI: 10.1016/j.jhazmat.2020.123315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 06/22/2020] [Accepted: 06/23/2020] [Indexed: 06/11/2023]
Abstract
This study assesses the potential of thermal processing for detoxification of wood-combustion ashes that contain high levels of Cr and Cd. Thermal treatment (1000 °C) of bottom ash and fly ash in an oxidising gas (air) atmosphere resulted in: low volatilisation of Cd and most other heavy metals, oxidation of Cr in the ashes to Cr (VI), and, in the case of the fly ash, significantly increased leaching of Cr and Mo. Thermal treatment in a nitrogen atmosphere resulted in local reducing conditions due to oxidation of ash-derived carbon to CO (g). Thermal treatments in this atmosphere and in a reducing atmosphere consisting of 10 % H2 and the balance N2 detoxified the ashes in at least two ways: (i) by substantially removing Cd, Pb, Bi, Tl, and, in the case of the fly ash, Zn from the ashes by volatilisation; and (ii) by thermal reduction of Cr (VI) in the ashes. There was at least a 100-fold reduction in the leaching of total Cr from both the bottom ash and the fly ash following the thermal treatments in reducing conditions. Chromium only leached from the detoxified bottom ash to a significant extent in acidic conditions (pH < 4).
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Affiliation(s)
- Daniel J Lane
- Fine Particle and Aerosol Technology Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland.
| | - Olli Sippula
- Fine Particle and Aerosol Technology Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland; Department of Chemistry, University of Eastern Finland, P.O. Box 111, FI-80101 Joensuu, Finland
| | - Sirpa Peräniemi
- School of Pharmacy, University of Eastern Finland, FI-70211 Kuopio, Finland
| | - Jorma Jokiniemi
- Fine Particle and Aerosol Technology Laboratory, Department of Environmental and Biological Sciences, University of Eastern Finland, P.O. Box 1627, FI-70211 Kuopio, Finland
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Torres Ospina A, Zapata JA, Gil Gonzalez JH, Giraldo L, Valencia DM. Colorimetric method as alternative to chromium (III) quantification in cattle feces. ACTA SCIENTIARUM: ANIMAL SCIENCES 2020. [DOI: 10.4025/actascianimsci.v42i1.48096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
One of the main factors to establish productivity of grazing cattle is the estimation of forage intake. For this, the most widely used technique is based on the estimation of fecal output using chromium dioxide as external marker. However, quantification can be expensive and sometimes not precise due to the methodology used for this purpose. Therefore, the aim of this study was to validate the colorimetric method for chromium quantification and to implement it in the estimation of fecal output in grazing cattle. The temperature, the digestion time and the wavelength for the measurement were evaluated. The method was validated for selectivity, linearity, detection and quantification limits, precision, accuracy, and stability. Results showed that temperature and digestion time are critical to improve sensitivity and quantification limits. The validation demonstrated that the method is suitable for the quantification of Cr2O3 in a wide range of concentrations, being statistically comparable with a reference method, and offering a reliable low cost and easy to implement alternative, to estimate fecal output in bovine digestibility studies.
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Yang Y, Ma H, Chen X, Zhu C, Li X. Effect of incineration temperature on chromium speciation in real chromium-rich tannery sludge under air atmosphere. ENVIRONMENTAL RESEARCH 2020; 183:109159. [PMID: 32028182 DOI: 10.1016/j.envres.2020.109159] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Revised: 01/17/2020] [Accepted: 01/20/2020] [Indexed: 06/10/2023]
Abstract
As a hazardous waste, the disposal of chromium enriched tannery sludge has attracted increasing public concern due to its potential adverse risks towards the environment. And incineration is considered to be an effective method to stabilize heavy metals, like Cr, in solid phase during tannery sludge treatment. In this study, real chromium enriched tannery sludge without pre-treatment was incinerated at 300°C-1200 °C under air atmosphere to investigate the transformation of chromium speciation. Here detailed thermal behavior, phase transformation and chromium speciation were characterized by TG-DSC, XRD and XPS, respectively. Experimental results show that content of Cr(VI) increases gradually with the increase of temperature from 300 °C to 500 °C and reaches a maximal level of 46% total Cr at 500 °C, with different Cr(VI) species of CaCrO4, MgCrO4 and Cr5O12. However, the content of Cr(VI) decreases gradually with the further increase of temperature, with only about 5% Cr(VI) at high temperature of 1200 °C, due to formation of Cr(III) species of Cr2O3 crystallite and MgCr2O4 spinel. Besides, a growing number of hexagonally shaped flake-like crystallite Cr2O3 can be discovered from characterization results of XRD and SEM. Finally, the reduction of CaCrO4 to Cr2O3 in the presence of SiO2 is thermodynamically feasible over 700 °C, indicating possible transformation of Cr(VI) to Cr(III) through controlled incineration temperature.
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Affiliation(s)
- Yonglin Yang
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China; School of Chemical Engineering, Shenmu Vocational & Technical College, Shenmu, 719300, PR China
| | - Hongrui Ma
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China.
| | - Xiangping Chen
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China.
| | - Chao Zhu
- School of Environmental Science and Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
| | - Xiaojie Li
- School of Chemistry and Chemical Engineering, Shaanxi University of Science & Technology, Xi'an, 710021, PR China
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Famielec S. Chromium Concentrate Recovery From Solid Tannery Waste in a Thermal Process. MATERIALS (BASEL, SWITZERLAND) 2020; 13:E1533. [PMID: 32230735 PMCID: PMC7177480 DOI: 10.3390/ma13071533] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 03/14/2020] [Accepted: 03/25/2020] [Indexed: 12/02/2022]
Abstract
Leather processing requires substantial inputs of energy, water and chemicals. Additionally, it generates significant amounts of liquid and solid waste, severely impacting the environment. Processing 1 Mg of raw hides yields up to 600-700 kg of waste, considerable amounts of which are solid tannery waste. Such waste contains chromium (Cr) compounds, which are commonly used as tanning agents. This paper reviews solid tannery waste treatment technologies, with emphasis on waste incineration in a specially designed experimental tunnel incinerator. Three different types of tannery waste were subjected to tests: trimmings, shavings and buffing dust. As the research revealed, the process can be applied to all types of solid tannery waste. Moreover, it enables the reuse of the heat of the process and results in a Cr concentrate in the process residues. The conducted analyses (carbon, hydrogen and nitrogen elemental analysis; inductively coupled plasma optical emission spectroscopy; powder X‑ray diffraction) proved that there is no or little organic content in the obtained residual ash, which contains up to 53.1%(w/w) Cr in the form of Cr (III) oxide. Such material may be used as a Cr ore substitute in the chemical or metallurgical industries.
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Affiliation(s)
- Stanisław Famielec
- Faculty of Production and Power Engineering, University of Agriculture in Krakow, Balicka 116 B, 30-149 Kraków, Poland
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Dai Y, Li Y, Xu X, Zhu Q, Yan W, Jin S, Harmuth H. Fracture behaviour of magnesia refractory materials in tension with the Brazilian test. Ann Ital Chir 2019. [DOI: 10.1016/j.jeurceramsoc.2019.07.026] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Burton ED, Choppala G, Vithana CL, Karimian N, Hockmann K, Johnston SG. Chromium(VI) formation via heating of Cr(III)-Fe(III)-(oxy)hydroxides: A pathway for fire-induced soil pollution. CHEMOSPHERE 2019; 222:440-444. [PMID: 30716546 DOI: 10.1016/j.chemosphere.2019.01.172] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Revised: 11/30/2018] [Accepted: 01/29/2019] [Indexed: 06/09/2023]
Abstract
Mixed Cr(III)-Fe(III) (oxy)hydroxides are important Cr-bearing phases in natural, unpolluted soil. Fires frequently affect large areas of land around the world, causing the temporary development of elevated soil temperatures. This study examines the hypothesis that heating Cr(III)-Fe(III) (oxy)hydroxides at temperatures which occur in surface soils during fires can drive rapid oxidation of Cr(III) to hazardous Cr(VI). To test this, poorly-ordered Cr(III)x-Fe(III)1-x (oxy)hydroxides, with x spanning 0.1 to 0.9, were heated at up to 800 °C for 2 h. Heating at 400-800 °C produced a highly crystalline hematite-eskolaite solid-solution (FeIII2-nCrIIInO3, where n ranges from 0 to 2). Chromium K-edge X-ray absorption spectroscopy showed that during heating up to ∼40% of the initial Cr(III) was oxidized to Cr(VI), with the greatest extent of Cr(VI) formation occurring at 200-400 °C. At these temperatures, a substantial proportion (17%-70%) of the newly-formed Cr(VI) was exchangeable (i.e. extracted by a pH 7.2, 10 mM PO43- solution). This suggests that much of the Cr(VI) formed by heating of Cr(III)x-Fe(III)1-x (oxy)hydroxides at 200-400 °C is likely to be relatively mobile in fire-impacted soils. The results of this study provide new insights into a potentially-important pathway for the in-situ formation of Cr(VI) in soil.
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Affiliation(s)
- Edward D Burton
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW 2480, Australia.
| | - Girish Choppala
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW 2480, Australia
| | - Chamindra L Vithana
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW 2480, Australia; Department of Geology, Faculty of Science, University of Peradeniya, Peradeniya, Sri Lanka
| | - Niloofar Karimian
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW 2480, Australia
| | - Kerstin Hockmann
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW 2480, Australia; University of Bayreuth, Environmental Geochemistry, Universitaetsstrasse 30, 95440, Bayreuth, Germany
| | - Scott G Johnston
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW 2480, Australia
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Burton ED, Choppala G, Karimian N, Johnston SG. A new pathway for hexavalent chromium formation in soil: Fire-induced alteration of iron oxides. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2019; 247:618-625. [PMID: 30711817 DOI: 10.1016/j.envpol.2019.01.094] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 01/22/2019] [Accepted: 01/22/2019] [Indexed: 06/09/2023]
Abstract
Iron oxides are important pedogenic Cr(III)-bearing phases which experience high-temperature alteration via fire-induced heating of surface soil. In this study, we examine if heating-induced alteration of Cr(III)-substituted Fe oxides can potentially facilitate rapid high-temperature oxidation of solid-phase Cr(III) to hazardous Cr(VI). Synthetic Cr(III)-substituted ferrihydrite, goethite and hematite were heated up to 800 °C for 2 h. Corresponding heating experiments were also conducted on an unpolluted Ferrosol-type soil, which had a total Cr content of 220 mg kg-1, initially undetectable Cr(VI) and Fe speciation comprising a mixture of hematite, goethite and ferrihydrite (according to Fe K-edge EXAFS spectroscopy). Up to ∼50% of the initial Cr(III) was oxidised to Cr(VI) during heating of Cr(III)-substituted ferrihydrite and hematite, with the greatest extent of Cr(VI) formation occurring at 200-400 °C. In contrast, heating of Cr(III)-substituted goethite resulted in up to ∼100% of Cr(III) oxidizing to Cr(VI) as the temperature approached 800 °C. In the Ferrosol-type soil, heating at ≥400 °C also resulted in large amounts of Cr(VI) formation, with a maximum total Cr(VI) concentration of 77 mg kg-1 forming at 600 °C (equating to oxidation of ∼35% of the soil's total Cr content). A relatively large portion (31-42%) of the total Cr(VI) which formed during heating of the soil was exchangeable, implying a high level of potential mobility and bioaccessibility. Overall, the results show that Cr(VI) forms rapidly via the oxidation of Fe oxide-bound Cr(III) at temperatures which occur in surface soils during fires. On this basis and given the frequency and extent of wild-fires around the world, we propose that fire-induced oxidation of Fe oxide-bound Cr(III) may represent a globally-significant pathway for the natural formation of hazardous Cr(VI) in surface soil.
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Affiliation(s)
- Edward D Burton
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW, 2480, Australia.
| | - Girish Choppala
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW, 2480, Australia
| | - Niloofar Karimian
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW, 2480, Australia
| | - Scott G Johnston
- Southern Cross University, Southern Cross GeoScience, Lismore, NSW, 2480, Australia
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Hu H, Shi M, Yang Y, Liu H, Xu M, Shen J, Yao H. Further Insight into the Formation and Oxidation of CaCr 2O 4 during Solid Fuel Combustion. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:2385-2391. [PMID: 29390188 DOI: 10.1021/acs.est.7b05538] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The control of toxic chromate (Cr6+) formation is still a significant challenge in solid fuel combustion. In particular, the mechanism of chromium transformation from Cr3+ to chromate or other unoxidized forms remains unclear. The present study confirms the formation of a significant unoxidized Cr-containing compound CaCr2O4(Cr3+) during solid fuel combustion. Experiments were conducted, for the first time, to clarify the mechanism of CaCr2O4 oxidation, which is quite different from Cr2O3 oxidation. The findings demonstrate that CaCr2O4 was formed at temperatures above 1200 K, through rapid decomposition of CaCrO4 or slow and direct interaction between CaO and Cr2O3. Compared to Cr2O3, CaCr2O4 could be oxidized at lower temperatures under the influence of free CaO. In the absence of free CaO, the oxidation of CaCr2O4 was minimal; however, in the presence of CaSO4, calcium in the form of CaCr2O4 participated in the oxidation of CaCr2O4. Thus, chromium in the form of CaCr2O4 was more likely to be oxidized when CaCr2O4-containing fly ash was reheated. Fortunately, CaCr2O4 showed slight basicity on the surface, allowing it to react with acidic gases. Accordingly, measures were proposed to suppress the oxidation of CaCr2O4 by stimulating the reactions between CaCr2O4 and acidic substances, like SO2 and Si/Al-compounds. These compounds competed with chromium at high temperatures to react with calcium in the fly ash and in CaCr2O4. As a result, the unoxidized chromium was transformed into highly stable Cr2O3 or Ca3Cr2 (SiO4)3.
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Affiliation(s)
- Hongyun Hu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
| | - Mengya Shi
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
| | - Yuhan Yang
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
| | - Huan Liu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
- Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
| | - Mian Xu
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
| | - Junhao Shen
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
| | - Hong Yao
- State Key Laboratory of Coal Combustion, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
- Department of New Energy Science and Engineering, School of Energy and Power Engineering, Huazhong University of Science and Technology , Wuhan 430074, P. R. China
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Sasaki K, Toshiyuki K, Guo B, Ideta K, Hayashi Y, Hirajima T, Miyawaki J. Calcination effect of borate-bearing hydroxyapatite on the mobility of borate. JOURNAL OF HAZARDOUS MATERIALS 2018; 344:90-97. [PMID: 29032098 DOI: 10.1016/j.jhazmat.2017.10.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2017] [Revised: 09/14/2017] [Accepted: 10/02/2017] [Indexed: 06/07/2023]
Abstract
Discharge from accidental nuclear power plants includes boric acid, which is used as a neutron absorbent in nuclear reactors. Co-precipitation of borate with hydroxyapatite (HAp), using Ca(OH)2, is known to be an effectively fast method for stabilization of borate as well as coexisting radioactive nuclides. To reduce bulky volume of solid residues after co-precipitation, calcination is necessary to investigate the chemical stability of targets. Calcination at 850°C resulted in the high crystalization of HAp with formation of xCaO·B2O3 as a by-phase in which x increased with a decrease in the borate contents. After calcination, the lattice parameter a of HAp showed a reentrant curve and c showed a convex curve with an increase in borate contents. A dissolution assay revealed that calcination sometimes increases the borate moiety and that the acceptable B contents in HAp are lower than 1.59mmol/g-calcined HAp. These results imply that during calcination of HAp, some borate is excluded to form the by-phase xCaO·B2O3, which is relatively insoluble in water, but some other fractions might be additionally emitted from the amorphous phase to weakly bind the calcined products.
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Affiliation(s)
- Keiko Sasaki
- Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan.
| | - Kenta Toshiyuki
- Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Binglin Guo
- Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Keiko Ideta
- Department of Advanced Device Materials, Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8180, Japan
| | - Yoshikazu Hayashi
- Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Tsuyoshi Hirajima
- Department of Earth Resources Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Jin Miyawaki
- Department of Advanced Device Materials, Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga 816-8180, Japan
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Miyake Y, Tokumura M, Iwazaki Y, Wang Q, Amagai T, Horii Y, Otsuka H, Tanikawa N, Kobayashi T, Oguchi M. Determination of hexavalent chromium concentration in industrial waste incinerator stack gas by using a modified ion chromatography with post-column derivatization method. J Chromatogr A 2017; 1502:24-29. [PMID: 28473202 DOI: 10.1016/j.chroma.2017.04.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Revised: 04/21/2017] [Accepted: 04/24/2017] [Indexed: 10/19/2022]
Abstract
An ion chromatography with post-column derivatization with 1,5-diphenylcarbazide (IC-DPC) analytical method was modified to enable measurement of trace-level hexavalent chromium (Cr(VI)) in air. One of the difficulties in determining trace levels of Cr(VI) in air with conventional IC-DPC methods is co-elution of the solvent and ion peaks due to high concentrations of ionic compounds in the extract. However, by using gradient elution rather than isocratic elution we were able to fully resolve the Cr(VI) ion peak from the solvent peak without the need for diluting the extract, which would have reduced the minimum quantifiable level of the method. With this method, we were able to detect Cr(VI) in air at concentrations of 5.3ng/m3 (assuming a sampling volume of 1m3 and a final solution volume of 10mL). Recovery tests at three different concentrations of Cr(VI) (50, 250, 1000ng) were performed with or without fly ash; recovery rates at all the concentrations of Cr(VI), with or without fly ash, ranged from 68% to 110% (mean±relative standard deviation, 96%±11%), and there were no differences in recovery rates with respect to the presence or absence of fly ash. Finally, we used the developed method to determine the concentration of Cr(VI) in stack gases collected from eight industrial waste incinerators located in Japan. The concentration of Cr(VI) in the stack gases ranged from below the method quantification limit to 3100ng/m3. The highest concentrations of Cr(VI) detected in the stack gases were two to three orders of magnitude higher than that in ambient air in Japan.
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Affiliation(s)
- Yuichi Miyake
- University of Shizuoka, 52-1 Yada Suruga-ku, Shizuoka 422-8526, Japan
| | - Masahiro Tokumura
- University of Shizuoka, 52-1 Yada Suruga-ku, Shizuoka 422-8526, Japan.
| | - Yuta Iwazaki
- University of Shizuoka, 52-1 Yada Suruga-ku, Shizuoka 422-8526, Japan
| | - Qi Wang
- University of Shizuoka, 52-1 Yada Suruga-ku, Shizuoka 422-8526, Japan
| | - Takashi Amagai
- University of Shizuoka, 52-1 Yada Suruga-ku, Shizuoka 422-8526, Japan.
| | - Yuichi Horii
- Center for Environmental Science in Saitama, 914 Kamitanadare, Kazo, Saitama 347-0115, Japan
| | - Hideyuki Otsuka
- Institute of Environmental Sciences, Hokkaido Research Organization, N19W12, Kita-ku, Sapporo, Hokkaido 060-0819, Japan
| | - Noboru Tanikawa
- Japan Industrial Waste Information Center, 2-3 Chiyoda-ku, Tokyo 102-0084, Japan
| | - Takeshi Kobayashi
- Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501, Japan
| | - Masahiro Oguchi
- National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba 305-8506, Japan
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Juel MAI, Mizan A, Ahmed T. Sustainable use of tannery sludge in brick manufacturing in Bangladesh. WASTE MANAGEMENT (NEW YORK, N.Y.) 2017; 60:259-269. [PMID: 28081994 DOI: 10.1016/j.wasman.2016.12.041] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 12/03/2016] [Accepted: 12/29/2016] [Indexed: 06/06/2023]
Abstract
Chromium-rich tannery sludge generated from tanneries has the potential to become a serious environmental burden in Bangladesh and a promising avenue for disposal of this sludge is by stabilizing it in clay brick products. But for sustainable industrial application of such technique it needs to be ensured first that the engineering properties of bricks as a building material are not diminished by addition of sludge, the process becomes energy efficient compared to alternatives and the use of such bricks do not pose any harmful environmental effects in the long run. In this study, clay bricks were prepared with different proportions of sludge (10%, 20%, 30% and 40% by dry weight) in both laboratory-controlled and field conditions and their suitability as a construction material was assessed based on their strength, water absorption, shrinkage, weight-loss on ignition and bulk density. For the sludge incorporated bricks, the compressive strength ranged from 10.98MPa to 29.61MPa and water absorption ranged from 7.2% to 20.9%, which in most cases met both the Bangladesh and ASTM criteria for bricks as a construction material. Volumetric shrinkage, weight loss and efflorescence properties of sludge-amended bricks were found to be favorable and it was estimated that an energy saving of 15-47% could potentially be achieved during firing with 10-40% tannery sludge-amended bricks. The quality of sludge-amended bricks made in the brick kiln was relatively inferior compared to bricks produced in the laboratory due to operating in a less-controlled environment with respect to maintaining adequate compaction and optimum moisture content. The leaching behavior of several heavy metals (Cr, As, Cu, Ni, Cd, Pb and Zn) from sludge-amended bricks has been found to be insignificant and far below the Dutch regulations and USEPA regulatory limits. Results from this study indicate that tannery sludge can be sustainably stabilized in clay bricks and large-scale application of this technique can be envisaged in the context of Bangladesh where brick remains a dominant building material.
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Affiliation(s)
- Md Ariful Islam Juel
- Department of Leather Engineering, Khulna University of Engineering and Technology, Khulna 9203, Bangladesh.
| | - Al Mizan
- Leather Research Institute, Bangladesh Council of Scientific and Industrial Research, Dhaka 1000, Bangladesh
| | - Tanvir Ahmed
- Department of Civil Engineering, Bangladesh University of Engineering and Technology, Dhaka 1000, Bangladesh
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Kasumba J, Hettick B, French A, Wickliffe JK, Lichtveld MY, Hawkins WB, van Sauers-Muller A, Klein D. Analysis of Pesticides and Toxic Heavy Metals Contained in Mosquito Coils. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 97:614-618. [PMID: 27699449 PMCID: PMC11185858 DOI: 10.1007/s00128-016-1938-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 09/27/2016] [Indexed: 06/06/2023]
Abstract
In this study, 10 mosquito coils manufactured in China were obtained in Suriname, South America, where they are used extensively. The coils were analyzed for organics (allethrin, permethrin, and butylated hydroxytoluene) and heavy metals (Cr, Co, As, Cd, and Pb) by GC-MS and ICP-MS, respectively. Allethrin was the only target organic compound detected in all mosquito coils with concentrations ranging from ~1900 to ~4500 µg/g. The concentrations of heavy metals varied as follows (in µg/g): Cr: 2.9-9.4, Co: 0.1-1.2, Cu: 0.7-16.1, Se: 0.10-0.4, Ni: 2.1-5.8, As: 0.10-2.2, Cd: 0.10-0.2, and Pb: 1.1-3.6.
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Affiliation(s)
- John Kasumba
- The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX, 79409-1163, USA.
| | - Bryan Hettick
- The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX, 79409-1163, USA
| | - Amanda French
- The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX, 79409-1163, USA
| | - Jeffrey K Wickliffe
- Department of Global Environmental Health Sciences, Tulane University, New Orleans, LA, 70112, USA
| | - Maureen Y Lichtveld
- Department of Global Environmental Health Sciences, Tulane University, New Orleans, LA, 70112, USA
| | - William B Hawkins
- Department of Global Environmental Health Sciences, Tulane University, New Orleans, LA, 70112, USA
| | | | - David Klein
- The Institute of Environmental and Human Health, Department of Environmental Toxicology, Texas Tech University, Lubbock, TX, 79409-1163, USA
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Mao L, Gao B, Deng N, Liu L, Cui H. Oxidation behavior of Cr(III) during thermal treatment of chromium hydroxide in the presence of alkali and alkaline earth metal chlorides. CHEMOSPHERE 2016; 145:1-9. [PMID: 26650573 DOI: 10.1016/j.chemosphere.2015.11.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Revised: 10/29/2015] [Accepted: 11/16/2015] [Indexed: 06/05/2023]
Abstract
The oxidation behavior of Cr(III) during the thermal treatment of chromium hydroxide in the presence of alkali and alkaline earth metal chlorides (NaCl, KCl, MgCl2, and CaCl2) was investigated. The amounts of Cr(III) oxidized at various temperatures and heating times were determined, and the Cr-containing species in the residues were characterized. During the transformation of chromium hydroxide to Cr2O3 at 300 °C approximately 5% of the Cr(III) was oxidized to form intermediate compounds containing Cr(VI) (i.e., CrO3), but these intermediates were reduced to Cr2O3 when the temperature was above 400 °C. Alkali and alkaline earth metals significantly promoted the oxidation of Cr(III) during the thermal drying process. Two pathways were involved in the influences the alkali and alkaline earth metals had on the formation of Cr(VI). In pathway I, the alkali and alkaline earth metals were found to act as electron transfer agents and to interfere with the dehydration process, causing more intermediate Cr(VI)-containing compounds (which were identified as being CrO3 and Cr5O12) to be formed. The reduction of intermediate compounds to Cr2O3 was also found to be hindered in pathway I. In pathway II, the alkali and alkaline earth metals were found to contribute to the oxidation of Cr(III) to form chromates. The results showed that the presence of alkali and alkaline earth metals significantly increases the degree to which Cr(III) is oxidized during the thermal drying of chromium-containing sludge.
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Affiliation(s)
- Linqiang Mao
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Bingying Gao
- College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China
| | - Ning Deng
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Lu Liu
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Hao Cui
- State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210046, PR China.
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Coronado M, Segadães AM, Andrés A. Using mixture design of experiments to assess the environmental impact of clay-based structural ceramics containing foundry wastes. JOURNAL OF HAZARDOUS MATERIALS 2015; 299:529-539. [PMID: 26252997 DOI: 10.1016/j.jhazmat.2015.07.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/02/2015] [Accepted: 07/05/2015] [Indexed: 06/04/2023]
Abstract
This work describes the leaching behavior of potentially hazardous metals from three different clay-based industrial ceramic products (wall bricks, roof tiles, and face bricks) containing foundry sand dust and Waelz slag as alternative raw materials. For each product, ten mixtures were defined by mixture design of experiments and the leaching of As, Ba, Cd, Cr, Cu, Mo, Ni, Pb, and Zn was evaluated in pressed specimens fired simulating the three industrial ceramic processes. The results showed that, despite the chemical, mineralogical and processing differences, only chrome and molybdenum were not fully immobilized during ceramic processing. Their leaching was modeled as polynomial equations, functions of the raw materials contents, and plotted as response surfaces. This brought to evidence that Cr and Mo leaching from the fired products is not only dependent on the corresponding contents and the basicity of the initial mixtures, but is also clearly related with the mineralogical composition of the fired products, namely the amount of the glassy phase, which depends on both the major oxides contents and the firing temperature.
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Affiliation(s)
- M Coronado
- Department of Chemistry and Process and Resources Engineering, University of Cantabria, 39005 Santander, Spain; Department of Materials and Ceramics Engineering (CICECO), University of Aveiro, 3810-193 Aveiro, Portugal
| | - A M Segadães
- Department of Materials and Ceramics Engineering (CICECO), University of Aveiro, 3810-193 Aveiro, Portugal
| | - A Andrés
- Department of Chemistry and Process and Resources Engineering, University of Cantabria, 39005 Santander, Spain.
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Mao L, Gao B, Deng N, Zhai J, Zhao Y, Li Q, Cui H. The role of temperature on Cr(VI) formation and reduction during heating of chromium-containing sludge in the presence of CaO. CHEMOSPHERE 2015; 138:197-204. [PMID: 26072117 DOI: 10.1016/j.chemosphere.2015.05.097] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 05/14/2015] [Accepted: 05/27/2015] [Indexed: 06/04/2023]
Abstract
In this study, the temperature dependence of Cr(VI) formation and reduction in the presence of CaO was examined during the thermal treatment of sludge that contains chromium. thermogravimetry-differential scanning calorimetry and X-ray diffractometry were used to characterize the thermal behavior and phase transformation, respectively. Na2CO3 leaching procedure was employed to determine the amount of Cr(VI). The result showed that CaO promoted Cr(III) oxidation, however, its influence is very dependent on heating temperature, with the extent of the effect varying with temperature. From 200-400 °C, the presence of CaO facilitated formation of intermediate product Cr2O3+x containing Cr(VI) during dehydration of chromium hydrate, while Cr2O3+x would decompose as temperature over 400 °C, accompanied by part of Cr(VI) being reduced to Cr(III). From 500 to 900 °C, Cr(III) reacted with CaO to form a leachable CaCrO4 product. This product was stable and a prolonged heating time did not reduce the amount of Cr(VI) significantly. At 1000-1200 °C, part of CaCrO4 was reduced to Ca(CrO2)2 in 1h. While extended heating time above 1h resulted in the Ca(CrO2)2 being oxidized reversibly to CaCrO4 at 1200 °C. Since CaCrO4 is thermodynamically less stable over 1000 °C, MgO could induce CaCrO4 to be reduced into MgCr2O4 at around 900 °C, lower than that for the reduction from CaCrO4 into Ca(CrO2)2. It suggested that adding MgO might be a potential approach for inhibiting Cr(VI) formation during heating sludge containing chromium.
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Affiliation(s)
- Linqiang Mao
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Bingying Gao
- College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410081, PR China
| | - Ning Deng
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Jianping Zhai
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Yongbin Zhao
- National Institute of Clean-and-low-carbon Energy (NICE), Beijing 102209, PR China
| | - Qin Li
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Nanjing 210046, PR China
| | - Hao Cui
- State Key Laboratory of Pollution Control and Resource Reuse, and School of the Environment, Nanjing University, Nanjing 210046, PR China.
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Verbinnen B, Block C, Van Caneghem J, Vandecasteele C. Recycling of spent adsorbents for oxyanions and heavy metal ions in the production of ceramics. WASTE MANAGEMENT (NEW YORK, N.Y.) 2015; 45:407-11. [PMID: 26174357 DOI: 10.1016/j.wasman.2015.07.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Revised: 06/25/2015] [Accepted: 07/01/2015] [Indexed: 05/22/2023]
Abstract
Spent adsorbents for oxyanion forming elements and heavy metals are classified as hazardous materials and they are typically treated by stabilization/solidification before landfilling. The use of lime or cement for stabilization/solidification entails a high environmental impact and landfilling costs are high. This paper shows that mixing spent adsorbents in the raw material for the production of ceramic materials is a valuable alternative to stabilize oxyanion forming elements and heavy metals. The produced ceramics can be used as construction material, avoiding the high economic and environmental impact of stabilization/solidification followed by landfilling. To study the stabilization of oxyanion forming elements and heavy metals during the production process, two series of experiments were performed. In the first series of experiments, the main pollutant, Mo was adsorbed onto iron-based adsorbents, which were then mixed with industrial sludge (3 w/w%) and heated at 1100°C for 30 min. Mo was chosen, as this element is easily adsorbed onto iron-based adsorbents and it is the element that is the most difficult to stabilize (i.e. the highest temperatures need to be reached before the concentrations in the leachate are reduced). Leaching concentration from the 97/3 sludge/adsorbent mixture before heating ranged between 85 and 154 mg/kg; after the heating process they were reduced to 0.42-1.48 mg/kg. Mo was actually stabilized, as the total Mo concentration after addition was not affected by the heat treatment. In the second series of experiments, the sludge was spiked with other heavy metals and oxyanion forming elements (Cr, Ni, Cu, Zn, As, Cd and Pb) in concentrations 5 times higher than the initial concentrations; after heat treatment the leachate concentrations were below the regulatory limit values. The incorporation of spent adsorbents in ceramic materials is a valuable and sustainable alternative to the existing treatment methods, saving raw materials in the ceramics production process and avoiding the use of stabilizing agents. Besides, spent adsorbents added to the raw material for ceramic products, may improve their aesthetic and structural properties.
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Affiliation(s)
- Bram Verbinnen
- KU Leuven - Department of Chemical Engineering, Process Engineering for Sustainable Systems (ProcESS), W. De Croylaan 46, B-3001 Heverlee, Belgium; KU Leuven - Faculty of Engineering Technology, Campus Groep T, Andreas Vesaliusstraat 13 - bus 2600, B-3000 Leuven, Belgium.
| | - Chantal Block
- KU Leuven - Department of Chemical Engineering, Process Engineering for Sustainable Systems (ProcESS), W. De Croylaan 46, B-3001 Heverlee, Belgium
| | - Jo Van Caneghem
- KU Leuven - Faculty of Engineering Technology, Campus Groep T, Andreas Vesaliusstraat 13 - bus 2600, B-3000 Leuven, Belgium
| | - Carlo Vandecasteele
- KU Leuven - Department of Chemical Engineering, Process Engineering for Sustainable Systems (ProcESS), W. De Croylaan 46, B-3001 Heverlee, Belgium
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Low F, Kimpton J, Wilson S, Zhang L. Chromium Reaction Mechanisms for Speciation using Synchrotron in-Situ High-Temperature X-ray Diffraction. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:8246-8253. [PMID: 26055512 DOI: 10.1021/acs.est.5b01557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We use in situ high-temperature X-ray diffraction (HT-XRD), ex-situ XRD and synchrotron X-ray absorption near edge structure spectroscopy (XANES) to derive fundamental insights into mechanisms of chromium oxidation during combustion of solid fuels. To mimic the real combustion environment, mixtures of pure eskolaite (Cr(3+)2O3), lime (CaO) and/or kaolinite [Al2Si2O5(OH)4] have been annealed at 600-1200 °C in air versus 1% O2 diluted by N2. Our results confirm for the first time that (1) the optimum temperature for Cr(6+) formation is 800 °C for the coexistence of lime and eskolaite; (2) upon addition of kaolinite into oxide mixture, the temperature required to produce chromatite shifts to 1000 °C with a remarkable reduction in the fraction of Cr(6+). Beyond 1000 °C, transient phases are formed that bear Cr in intermediate valence states, which convert to different species other than Cr(6+) in the cooling stage; (3) of significance to Cr mobility from the waste products generated by combustion, chromatite formed at >1000 °C has a glassy disposition that prevents its water-based leaching; and (4) Increasing temperature facilitates the migration of eskolaite particles into bulk lime and enhances the extent to which Cr(3+) is oxidized, thereby completing the oxidation of Cr(3+) to Cr(6+) within 10 min.
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Affiliation(s)
- Fiona Low
- †Department of Chemical Engineering, Monash University, GPO Box 36, Clayton, Victoria 3800, Australia
| | - Justin Kimpton
- ‡Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Sasha Wilson
- §School of Earth, Atmosphere and Environment, Monash University, Clayton, Victoria 3800, Australia
| | - Lian Zhang
- †Department of Chemical Engineering, Monash University, GPO Box 36, Clayton, Victoria 3800, Australia
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Kavouras P, Pantazopoulou E, Varitis S, Vourlias G, Chrissafis K, Dimitrakopulos GP, Mitrakas M, Zouboulis AI, Karakostas T, Xenidis A. Incineration of tannery sludge under oxic and anoxic conditions: study of chromium speciation. JOURNAL OF HAZARDOUS MATERIALS 2014; 283:672-679. [PMID: 25464309 DOI: 10.1016/j.jhazmat.2014.09.066] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 09/19/2014] [Accepted: 09/27/2014] [Indexed: 06/04/2023]
Abstract
A tannery sludge, produced from physico-chemical treatment of tannery wastewaters, was incinerated without any pre-treatment process under oxic and anoxic conditions, by controlling the abundance of oxygen. Incineration in oxic conditions was performed at the temperature range from 300°C to 1200°C for duration of 2h, while in anoxic conditions at the temperature range from 400°C to 600°C and varying durations. Incineration under oxic conditions at 500°C resulted in almost total oxidation of Cr(III) to Cr(VI), with CaCrO4 to be the crystalline phase containing Cr(VI). At higher temperatures a part of Cr(VI) was reduced, mainly due to the formation of MgCr2O4. At 1200°C approximately 30% of Cr(VI) was reduced to Cr(III). Incineration under anoxic conditions substantially reduced the extent of oxidation of Cr(III) to Cr(VI). Increase of temperature and duration of incineration lead to increase of Cr(VI) content, while no chromium containing crystalline phase was detected.
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Affiliation(s)
- P Kavouras
- School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
| | - E Pantazopoulou
- Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece
| | - S Varitis
- School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - G Vourlias
- School of Physics, Section of Applied Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - K Chrissafis
- School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - G P Dimitrakopulos
- School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - M Mitrakas
- Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - A I Zouboulis
- Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece
| | - Th Karakostas
- School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - A Xenidis
- School of Mining Engineering and Metallurgy, National Technical University of Athens, Zografou Campus, Athens 15780, Greece
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48
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Verbinnen B, Billen P, Vandecasteele C. Thermal treatment of solid waste in view of recycling: Chromate and molybdate formation and leaching behaviour. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2014; 32:536-542. [PMID: 24794032 DOI: 10.1177/0734242x14532004] [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] [Indexed: 06/03/2023]
Abstract
Elevated Cr and Mo concentrations are often found in leachates of thermally treated solid waste, but there is no general explanation for this so far. Therefore, we studied the leaching behaviour after thermal treatment as a function of heating temperature and residence time for two types of solid waste: contaminated sludge and bottom ash from municipal solid waste incineration. The leaching behaviour of both waste streams was compared with experiments on synthetic samples, allowing deduction of a general mechanism for Cr and Mo leaching. Cr and Mo showed a similar leaching behaviour: after an initial increase, the leaching decreased again at higher temperatures. Oxidation of these elements from their lower oxidation states to chromate and molybdate at temperatures up to 600 °C was responsible for the increased leaching. At higher temperatures, both Mo and Cr leaching decreased again owing to the formation of an amorphous phase, incorporating the newly formed chromate and molybdate salts, which prevents them from leaching.
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Affiliation(s)
- Bram Verbinnen
- Process Engineering for Sustainable Systems (ProcESS), Department of Chemical Engineering, University of Leuven, Heverlee, Belgium
| | - Pieter Billen
- Process Engineering for Sustainable Systems (ProcESS), Department of Chemical Engineering, University of Leuven, Heverlee, Belgium
| | - Carlo Vandecasteele
- Process Engineering for Sustainable Systems (ProcESS), Department of Chemical Engineering, University of Leuven, Heverlee, Belgium
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49
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De Boom A, Aubert JE, Degrez M. Carbonation of municipal solid waste incineration electrostatic precipitator fly ashes in solution. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2014; 32:406-413. [PMID: 24718362 DOI: 10.1177/0734242x14527637] [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] [Indexed: 06/03/2023]
Abstract
Carbonation was applied to a Pb- and Zn-contaminated fraction of municipal solid waste incineration electrofilter fly ashes in order to reduce heavy metal leaching. Carbonation tests were performed in solution, by Na2CO3 addition or CO2 bubbling, and were compared with washing (with water only). The injection of CO2 during the washing did not modify the mineralogy, but the addition of Na2CO3 induced the reaction with anhydrite, forming calcite. Microprobe analyses showed that Pb and Zn contamination was rather diffuse and that the various treatments had no effect on Pb and Zn speciation in the residues. The leaching tests indicated that carbonation using Na2CO3 was successful because it gave a residue that could be considered as non-hazardous material. With CO2 bubbling, Pb and Zn leaching was strongly decreased compared with material washed with water alone, but the amount of chromium extracted became higher than the non-hazardous waste limits for landfilling.
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50
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Chen J, Jiao F, Zhang L, Yao H, Ninomiya Y. Elucidating the mechanism of Cr(VI) formation upon the interaction with metal oxides during coal oxy-fuel combustion. JOURNAL OF HAZARDOUS MATERIALS 2013; 261:260-268. [PMID: 23969010 DOI: 10.1016/j.jhazmat.2013.07.023] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Revised: 07/09/2013] [Accepted: 07/12/2013] [Indexed: 06/02/2023]
Abstract
The thermodynamics underpinning the interaction of Cr-bearing species with basic metal oxides, i.e. K2O, Fe2O3, MgO and CaO, during the air and oxy-fuel combustion of coal have been examined. The synchrotron-based X-ray adsorption near-edge spectroscopy (XANES) was used for Cr speciation. For the oxides tested, Cr(VI) formation is dominated by the reduction potential of the metals. The oxides of Ca(2+) with high reduction potential favored the oxidation of Cr(III), same for K(+). The other two basic metals, Fe2O3 and MgO with lower reduction potentials reacted with Cr(III) to form the corresponding chromites at the temperatures above 600°C. Coal combustion experiments in drop-tube furnace have confirmed the rapid capture of Cr vapors, either trivalent or hexavalent, by CaO into solid ash. The existence of HCl in flue gas favored the vaporization of Cr as CrO2Cl2, which was in turn captured by CaO into chromate. Both Fe2O3 and MgO exhibited less capability on scavenging the Cr(VI) vapor. Particularly, MgO alone exhibited a low capability for capturing the vaporized Cr(III) vapors. However, its co-existence with CaO in the furnace inhibited the Cr(VI) formation. This is beneficial for minimizing the toxicity of Cr in the coal combustion-derived fly ash.
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Affiliation(s)
- Juan Chen
- Department of Chemical Engineering, Monash University, Clayton, GPO Box 36, Victoria 3800, Australia; State Key Laboratory of Coal Combustion, Huazhong University of Science & Technology, Wuhan 430074, China
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