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Liu Z, Fang W, Cai Z, Zhang J, Yue Y, Qian G. Garbage-classification policy changes characteristics of municipal-solid-waste fly ash in China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 857:159299. [PMID: 36216059 DOI: 10.1016/j.scitotenv.2022.159299] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 06/16/2023]
Abstract
Policy is a powerful tool determining solid-waste treatment and disposal. In 2019, China carried out the "garbage-classification policy" in 46 cities. So-called dry garbage is then separated from municipal solid waste and treated alone by incineration. This work investigated the influence of the policy on contents and leaching characterizations of municipal solid waste incineration fly ash. Median value of Cl was significantly increased from 17.43 wt% to 28.63 wt%. Median content of CaO maintained a similar value (51.21 wt% and 47.27 wt%). Ten year ago, CaClOH was not generally observed in fly ash. However, this phase was widely detected nowadays. Median value of heavy-metal (Zn, Pb, Cu, Cd, Cr, and Ni) was decreased from 9007.69 mg/kg to 7652.72 mg/kg. Thus, the policy also positively affected hazardous-waste collection. Heavy-metal leaching concentrations were decreased and chemical speciation became more stable because CaClOH supplied more alkalinity and binding ability for heavy metals. Therefore, fly-ash treatment technologies and their running parameters should be regulated to adapt above new characterizations after the garbage-classification policy.
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Affiliation(s)
- Zixing Liu
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China; Design Institute 5, Shanghai Municipal Engineering Design and Research Institute (Group) Co., Ltd., NO. 901 North Zhongshan Road (2nd), Shanghai 200092, PR China
| | - Wanyu Fang
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China
| | - Zixiang Cai
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China.
| | - Jia Zhang
- SHU Center of Green Urban Mining & Industry Ecology, School of Environmental and Chemical Engineering, Shanghai University, No. 381 Nanchen Road, Shanghai 200444, PR China.
| | - Yang Yue
- MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China.
| | - Guangren Qian
- MGI of Shanghai University, Xiapu Town, Xiangdong District, Pingxiang City, Jiangxi 337022, PR China.
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Ren M, Zhang H, Fan Y, Zhou H, Cao R, Gao Y, Chen J. Suppressing the formation of chlorinated aromatics by inhibitor sodium thiocyanate in solid waste incineration process. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 798:149154. [PMID: 34333438 DOI: 10.1016/j.scitotenv.2021.149154] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 07/15/2021] [Accepted: 07/16/2021] [Indexed: 06/13/2023]
Abstract
Suppressing the formation of chlorinated aromatics (Cl-aromatics) by chemical inhibitors is an important measure to reduce dioxin emission from the solid waste incineration plants. In this study, we first investigated the reduction effect of a novel inhibitor sodium thiocyanate (NaSCN) on the emission of dioxins in 2 full-scale solid waste incineration systems. Injection of NaSCN solution into the higher temperature flue gas resulted in about 60% reduction in the concentration of total tetra- to octa-chlorinated dibenzo-p-dioxins and dibenzofurans in stack flue gas. The suppression effect was further verified by a laboratory study on the chlorination of naphthalene over model fly ashes with or without NaSCN addition. By characterizing the reaction products between NaSCN and key catalysts Cu and Fe chlorides, two main suppression mechanisms were proposed: (i) reduction of highly active cupric chloride (CuCl2) and ferric chloride (FeCl3) to less active cuprous chloride (CuCl) and ferrous chloride (FeCl2), (ii) sulfidation of Cu chlorides. The laboratory study indicated that the unreacted NaSCN in the combustion flue gas could be mainly decomposed into Na2S, C3N4, Na2S2O3, NaS2, Na2SO4, CO2, SO2, NO2 and COS. These decomposition products are low toxic or can be effectively removed by the air pollution control devices. CAPSULE: NaSCN suppressed the formation of chlorinated aromatics in combustion flue gas mainly through inducing the reduction of highly active Cu (II) and Fe (III) chlorides.
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Affiliation(s)
- Meihui Ren
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Haijun Zhang
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China.
| | - Yun Fan
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Hongquan Zhou
- Shanghai Environmental Sanitation Engineering Design Institute Co., Ltd., Shanghai 200232, China
| | - Rong Cao
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Yuan Gao
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
| | - Jiping Chen
- CAS Key Laboratory of Separation Sciences for Analytical Chemistry, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023, China
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Lu S, Xiang Y, Chen Z, Chen T, Lin X, Zhang W, Li X, Yan J. Development of phosphorus-based inhibitors for PCDD/Fs suppression. WASTE MANAGEMENT (NEW YORK, N.Y.) 2021; 119:82-90. [PMID: 33049516 DOI: 10.1016/j.wasman.2020.09.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Revised: 08/03/2020] [Accepted: 09/11/2020] [Indexed: 06/11/2023]
Abstract
Inhibition mechanisms of sulfur-, nitrogen- and phosphorus- based inhibitors on the de novo synthesis of polychlorinated dibenzo-p-dioxins, and dibenzofurans (PCDD/F) were studied by exploring speciation evolution of carbon, chorine and copper in fly ash under laboratory-scale experiments. Significant inhibition of PCDD/Fs by thiourea (TUA) and ammonium dihydrogen phosphate (ADP) was observed as 97.2% and 98.2%, respectively, except for potassium dihydrogen phosphate (PDP). ADP and PDP exhibited better inhibition on PCDFs than on PCDDs, whereas TUA exhibited the opposite effect. After adding inhibitors, the proportion of C-O/C=O/O-C=O bonds at the surface of fly ash increased, and stronger oxidation of carbon occurred, together with the conversion from Cu2+ to Cu+ and the inhibition of organic chlorine formation. Kinetic model results indicated that TUA might either suppress the carbon gasification or promote the decomposition of PCDD/Fs, resulting in a remarkable inhibition of PCDD/Fs formation. Simulated chemical reaction equilibrium further comfirmed that catalytic metal could be deactivated into CuS and Cu2S by sulfur, and into Cu2P2O7 by phosphorus. Moreover, NH3, decomposed from TUA and ADP, was able to convert Cl2 into HCl, albeit with a weaker chlorination ability. This study of inhibition mechanisms is useful for the exploration and utilization of efficient inhibitors in full-scale incinerators.
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Affiliation(s)
- Shengyong Lu
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
| | - Yifan Xiang
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
| | - Zhiliang Chen
- Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN, USA
| | - Tong Chen
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Xiaoqing Lin
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China.
| | - Weifeng Zhang
- POWERCHINA Central China Electric Power Engineering Co., Ltd, China
| | - Xiaodong Li
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
| | - Jianhua Yan
- State Key Laboratory for Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou 310027, China
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Prisciandaro M, Piemonte V, di Celso GM, Ronconi S, Capocelli M. Thermodynamic features of dioxins' adsorption. JOURNAL OF HAZARDOUS MATERIALS 2017; 324:645-652. [PMID: 27866764 DOI: 10.1016/j.jhazmat.2016.11.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 10/30/2016] [Accepted: 11/14/2016] [Indexed: 06/06/2023]
Abstract
In this paper, the six more poisonous species among all congeners of dioxin group are taken into account, and the P-T diagram for each of them is developed. Starting from the knowledge of vapour tensions and thermodynamic parameters, the theoretical adsorption isotherms are calculated according to the Langmuir's model. In particular, the Langmuir isotherm parameters (K and wmax) have been validated through the estimation of the adsorption heat (ΔHads), which varies in the range 20-24kJ/mol, in agreement with literature values. This result will allow to put the thermodynamical basis for a rational design of different process units devoted to dioxins removal.
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Affiliation(s)
- Marina Prisciandaro
- Department of Industrial and Information Engineering and of Economics, University of L'Aquila, Viale Giovanni Gronchi 18, L'Aquila 67100, Italy
| | - Vincenzo Piemonte
- Faculty of Engineering, University Campus Biomedico of Rome, Via Alvaro del Portillo 21, Rome 00128, Italy.
| | | | - Silvia Ronconi
- Arta Abruzzo, Department of L'Aquila, Bazzano (AQ), 67100 L'Aquila, Italy
| | - Mauro Capocelli
- Faculty of Engineering, University Campus Biomedico of Rome, Via Alvaro del Portillo 21, Rome 00128, Italy
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Fujimori T, Nakamura M, Takaoka M, Shiota K, Kitajima Y. Synergetic inhibition of thermochemical formation of chlorinated aromatics by sulfur and nitrogen derived from thiourea: Multielement characterizations. JOURNAL OF HAZARDOUS MATERIALS 2016; 311:43-50. [PMID: 26954475 DOI: 10.1016/j.jhazmat.2016.02.054] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 01/25/2016] [Accepted: 02/24/2016] [Indexed: 06/05/2023]
Abstract
Nitrogen and sulfur (N/S)-containing compounds inhibit the formation of polychlorinated dibenzo-p-dioxins (PCDDs) and furans (PCDFs) in thermal processes. However, few studies have examined the inhibition mechanisms of N/S-containing compounds. In the present study, we focused on thiourea [(NH2)2CS] as such a compound and investigated its inhibition effects and mechanisms. The production of PCDD/Fs, polychlorinated biphenyls (PCBs), and chlorobenzenes (CBzs) were inhibited by >99% in the model fly ash in the presence of 1.0% thiourea after heating at 300 °C. Experimental results using real fly ash series were indicative of the thermal destruction of these chlorinated aromatics by thiourea. Multielement characterization using K-edge X-ray absorption fine structures of copper, chlorine, sulfur, nitrogen, and carbon revealed three possible inhibition paths, namely, (a) sulfidization of the copper catalyst to CuS, Cu2S, and CuSO4; (b) blocking the chlorination of carbon via the reaction of chlorine with N-containing compounds to generate ammonium chloride and other minor compounds; and (c) changing the carbon frame involved in attacking the carbon matrix by sulfur and nitrogen. Thus, thiourea plays a role as a sulfur and nitrogen donor to achieve multiple and synergistic inhibition of chlorinated aromatics. Our results suggest that other N/S-containing inhibitors function based on similar mechanisms.
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Affiliation(s)
- Takashi Fujimori
- Department of Global Ecology, Graduate School of Global Environmental Studies, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan.
| | - Madoka Nakamura
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan
| | - Masaki Takaoka
- Department of Global Ecology, Graduate School of Global Environmental Studies, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan; Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan
| | - Kenji Shiota
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Katsura, Nisikyo-ku, Kyoto 615-8540, Japan
| | - Yoshinori Kitajima
- Photon Factory, Institute of Materials Structure Science (IMSS), High Energy Accelerator Research Organization (KEK), Oho 1-1, Tsukuba, Ibaraki 305-0801, Japan
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Schwartz CP, Prendergast D. Communication: On the difficulty of reproducibly measuring PbCl2 X-ray absorption spectra. J Chem Phys 2015; 143:111102. [DOI: 10.1063/1.4931404] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Craig P. Schwartz
- Stanford Synchrotron Radiation Laboratory, SLAC National Accelerator Lab, Menlo Park, California 94025, USA
| | - David Prendergast
- Molecular Foundry, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
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Fujimori T, Takaoka M. Thermochemical chlorination of carbon indirectly driven by an unexpected sulfide of copper with inorganic chloride. JOURNAL OF HAZARDOUS MATERIALS 2011; 197:345-351. [PMID: 22004834 DOI: 10.1016/j.jhazmat.2011.09.089] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Revised: 09/26/2011] [Accepted: 09/26/2011] [Indexed: 05/31/2023]
Abstract
Unintentional anthropogenic thermal chlorination of carbon is known to be a contributor to global environmental pollution of organochlorine compounds. We found unexpected, serious chlorination of carbon promoted by a "sulfide" of copper, which has been generally thought of and studied as an inactive metal catalyst. Our quantitative and X-ray spectroscopic results show that a fraction of cupric sulfide indirectly promoted thermochemical solid-phase formation of a large quantity of organochlorine compounds such as polychlorinated dibenzo-p-dioxins, dibenzofurans, biphenyls, and benzenes that used inactive inorganic chloride as chlorine storage, which partly caused environmental pollution by organochlorine compounds.
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Affiliation(s)
- Takashi Fujimori
- Department of Environmental Engineering, Graduate School of Engineering, Kyoto University, Nisikyo-ku, Kyoto, Japan.
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