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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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Zhang P, Zeng L, Zhang S, Li C, Li D. Solidification/stabilization of chromite ore processing residue via co-sintering with hazardous waste incineration residue. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2023; 30:29392-29406. [PMID: 36417072 DOI: 10.1007/s11356-022-24318-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/15/2022] [Indexed: 06/16/2023]
Abstract
In order to realize the harmless and resource disposal of hazardous waste incineration residue (HWIR) and chromite ore processing residue (COPR), this paper prepares glass-ceramics by HWIR. The COPR was co-sintered with the base glass of HWIR to realize the solidification and stabilization of COPR. The results shown that the single-stage sintering method has a simple process and low energy consumption, while the two-stage sintering method has better mechanical properties. Chromium in COPR may be solidified/stabilized by physical encapsulation and chemical fixation. When the content of COPR reaches 50%, the leaching concentration of Cr and Cr(VI) in the solidified body of HWIR solidified COPR (IRSC) is less than 5 mg/L, which satisfies the US EPA and CN GB5085.3 standard limits. This study achieves waste control by waste and prepares solidified bodies (IRSC) with good mechanical properties, chemical corrosion resistance, and low leaching concentration of heavy metals, which provides feasibility for its engineering application.
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Affiliation(s)
- Pengpeng Zhang
- College of Resource and Safety Engineering, Chongqing University, Chongqing, 400044, China
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China
| | - Linghao Zeng
- College of Resource and Safety Engineering, Chongqing University, Chongqing, 400044, China
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China
| | - Shihao Zhang
- School of Architecture and Urban Planning, Chongqing University, Chongqing, 400044, China
| | - Chuanwei Li
- College of Resource and Safety Engineering, Chongqing University, Chongqing, 400044, China
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China
| | - Dongwei Li
- College of Resource and Safety Engineering, Chongqing University, Chongqing, 400044, China.
- State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing, 400044, China.
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Shen D, Bao Q, Qiu J, Gu F, Wu Z, Wu M, Guo W, Long Y. Effect of calcium oxide on chromium solidification during the melting of hazardous waste incineration fly ash. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2022; 317:115475. [PMID: 35662047 DOI: 10.1016/j.jenvman.2022.115475] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Revised: 05/29/2022] [Accepted: 05/31/2022] [Indexed: 06/15/2023]
Abstract
Thermal treatment technology considerably affects the harmlessness of fly ash (FA), but highly toxic heavy metals, such as Cr, attract considerable attention. In this study, we investigated the influence of CaO dosage at 600°C-1200 °C on the curing effect of Cr during FA thermal treatment based on the combination effect of CaO. Static, dynamic, and continuous sequential leachings were performed for the sintered products. Results showed that the leaching concentration of Cr decreased by approximately 91% when CaO dosage was 8.57%, and the difference in the residual state was the main reason for the difference in the leaching behavior of Cr. The proportion of the residual state in the sintered products increased from 35.16% to 64.01%. The transition between Cr2O3, Cr5O12, and CaCr2O4 is the fundamental reason for the leaching behavior of Cr and the change in the residual state. This study provides a scientific basis for preventing and controlling heavy metal pollution and optimizing environmental supervision in the FA thermal treatment process.
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Affiliation(s)
- Dongsheng Shen
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; Instrumental Analysis Center of Zhejiang Gongshang University, Hangzhou, 310018, China
| | - Qiqi Bao
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Junjian Qiu
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Foquan Gu
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Zixiao Wu
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Minjin Wu
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Wenxin Guo
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China
| | - Yuyang Long
- Zhejiang Provincial Key Laboratory of Solid Waste Treatment and Recycling, School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou, 310012, China; Instrumental Analysis Center of Zhejiang Gongshang University, Hangzhou, 310018, China.
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Zhu Z, Huang Y, Zha J, Yu M, Cheng H, Zhang Z, Dong L, Li Z, Fan C. Transformation of Cr under sintering of Ca-rich solid waste with kaolin: Analysis of multi-element coupled interactions. CHEMOSPHERE 2022; 287:132181. [PMID: 34583297 DOI: 10.1016/j.chemosphere.2021.132181] [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: 03/16/2021] [Revised: 07/22/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
The high toxicity of Cr-Ca compounds generated during the heat treatment of solid waste will heavily threat the environment. In this work, a kind of Ca-rich river sludge which is bound with Ca and heavy metals was combusted with kaolin under 900 °C for 3 h in a muffle to study the transformation of Cr. The effects of kaolin on Cr transformation were investigated through sequential extraction, the risk assessment of heavy metals, and constant pH leaching test, also combined with crystal phase analysis of Ca-Al-Si minerals. The experimental results showed that the formation of Ca10(SiO4)3(SO4)3Cl2 was inhibited by the addition of 10% (mass fraction) kaolin and the released Cl promoted the evaporation of target elements in priority while 30% kaolin addition further inhibited the solidification of Cr. Furthermore, the effect of NaCl and CaCO3 on the Cr solidification by kaolin were also explored by leaching procedure or XRD analysis of calcination products of their mixtures. It should be noticed that the addition of kaolin in Cr2O3-CaCO3 mixture will directly react with CaCrO4 and fixed the generated Cr2O3 into internal layered structure, preventing its re-oxidization by the free CaO. This work aims to help illustrate the Cr transformation with existence of Ca during sintering of Ca-rich solid wastes and reduce the Cr contamination in future.
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Affiliation(s)
- Zhicheng Zhu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Yaji Huang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China.
| | - Jianrui Zha
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China.
| | - Mengzhu Yu
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Haoqiang Cheng
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Zhenrong Zhang
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Lu Dong
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Zhiyuan Li
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
| | - Conghui Fan
- Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, School of Energy and Environment, Southeast University, Nanjing, 210096, China
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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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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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Mao L, Wu Y, Zhang W, Huang Q. The reuse of waste glass for enhancement of heavy metals immobilization during the introduction of galvanized sludge in brick manufacturing. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2019; 231:780-787. [PMID: 30415171 DOI: 10.1016/j.jenvman.2018.10.120] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/15/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
The mixing of galvanized sludge in fired clay brick manufacturing has been regarded as an alternative approach for the consumption of galvanized sludge. Decreasing the surface area and porosity of fired brick definitely lowers the risk of heavy metal release. In this study, a novel method is proposed to reduce the surface area and porosity of bricks and promote heavy metal immobilization by adding waste glass. The introduction of waste glass enhanced the physical and mechanical performances of fired clay bricks and resulted in an increase in bulk density and compressive strength and a decrease in water absorption. Microstructure analysis showed that the texture of the bricks turned from porous to smooth and homogeneous due to the introduction of waste glass. Porosity analysis showed that surface area and pore volume of fired brick were substantially reduced. When the added waste glass amount exceeded 15 wt%, the heavy metal concentrations that leached from bricks containing 10 wt% galvanized sludge fired at 950 °C met the regulatory requirement. These results demonstrate that waste glass can be reused to enhance the stabilization/solidification of heavy metals, during the mixing of hazardous waste in bricks and ceramics manufacturing process.
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Affiliation(s)
- Linqiang Mao
- School of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, PR China; Department of Mining Engineering, West Virginia University, Morgantown, 26506, United States.
| | - Yunqiu Wu
- 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
| | - Qingqing Huang
- Department of Mining Engineering, West Virginia University, Morgantown, 26506, United States
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Weng W, Wang M, Gong X, Wang Z, Wang D, Guo Z. Direct electro-deposition of metallic chromium from K2CrO4 in the equimolar CaCl2-KCl molten salt and its reduction mechanism. Electrochim Acta 2016. [DOI: 10.1016/j.electacta.2016.06.142] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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