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Tang Y, Tao D, Li G, Ye C, Bu Z, Shen R, Lin Y, Lv W. Formation behavior of PCDD/Fs during waste pyrolysis and incineration: Effect of temperature, calcium oxide addition, and redox atmosphere. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2024; 350:124011. [PMID: 38641034 DOI: 10.1016/j.envpol.2024.124011] [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: 01/10/2024] [Revised: 04/13/2024] [Accepted: 04/16/2024] [Indexed: 04/21/2024]
Abstract
The clean and efficient utilization of municipal solid waste (MSW) has attracted increasing concerns in recent years. Pyrolysis of MSW is one of the promising options due to the production of high-value intermediates and the inhibition of pollutants at reducing atmosphere. Herein, the formation behavior of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) during MSW pyrolysis and incineration was experimentally investigated and compared. The influence of reaction temperature, CaO addition, and redox atmosphere on PCDD/Fs formation were compared and discussed. The results showed as the pyrolysis temperature increased, the mass concentration and international toxicity equivalence quantity of PCDD/Fs initially peaked at ∼750 °C before declining. Most of the generated PCDD/Fs were concentrated in the liquid and gaseous products, accounting for ∼90% of the total. Among liquid products, octachlorodibenzo-p-dioxin (O8CDD), 2,3,4,7,8-pentachlorodibenzofuran and 1,2,3,4,6,7,8-heptachlorodibenzofuran (H7CDF) were the most crucial mass concentration contributors, while in gas products, high-chlorinated PCDD/Fs, such as O8CDD, octachlorodibenzofuran (O8CDF) and 1,2,3,4,6,7,8-H7CDF were predominant. Compared to incineration, the formation of PCDD/Fs was 7-20 times greater than that from pyrolysis. This discrepancy can be attributed to the hydrogen-rich and oxygen-deficient atmosphere during pyrolysis, which effectively inhibited the Deacon reaction and the formation of C-Cl bonds, thereby reducing the active chlorine in the system. The addition of in-situ CaO additives also decreased the active chlorine content in the system, bolstering the inhibiting of PCDD/Fs formation during MSW pyrolysis.
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Affiliation(s)
- Yuanjun Tang
- Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China.
| | - Dongsheng Tao
- Zhejiang Ecowell Energy Management Technology Co., Ltd. Hangzhou, Zhejiang, 310012, China
| | - Guoneng Li
- Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China
| | - Chao Ye
- Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China
| | - Zhongming Bu
- Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China
| | - Rong Shen
- Department of Energy and Environment System Engineering, Zhejiang University of Science and Technology, Hangzhou, 310023, China
| | - Yonghui Lin
- Zhejiang Ecowell Energy Management Technology Co., Ltd. Hangzhou, Zhejiang, 310012, China
| | - Wei Lv
- Zhejiang Ecowell Energy Management Technology Co., Ltd. Hangzhou, Zhejiang, 310012, China
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Li C, Zhang C, Ran F, Yao T, Lan X, Li H, Bai J, Lei Y, Zhou Z, Cui X. Effects of microbial deodorizer on pig feces fermentation and the underlying deodorizing mechanism. WASTE MANAGEMENT (NEW YORK, N.Y.) 2024; 174:174-186. [PMID: 38056366 DOI: 10.1016/j.wasman.2023.12.003] [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: 02/04/2023] [Revised: 11/20/2023] [Accepted: 12/02/2023] [Indexed: 12/08/2023]
Abstract
Microbial deodorization is a novel strategy for reducing odor in livestock and poultry feces. Herein, 12 strains of ammonia (NH3) and 15 hydrogen sulfide (H2S) removing bacteria were obtained with a removal efficiency of 65.20-79.80% and 34.90-79.70%, respectively. A novel bacteria deodorant named MIX (Bacillus zhangzhouensis, Bacillus altitudinis, and Acinetobacter pittii at a ratio of 1:1:2) were obtained. MIX can shorten the temperature rising stage by 2 days and prolong the thermophilic stage by 4 days. The ability of MIX to remove NH3, H2S, and volatile fatty acids (VFAs) and the underlying removal mechanism were analyzed during pig feces fermentation. MIX can significantly reduce the concentrations of NH3 and H2S by 41.82% and 66.35% and increase the concentrations of NO3--N and SO42- by 7.80% and 8.83% (P < 0.05), respectively, on the 25th day. Moreover, the concentrations of acetic, propionate, iso-valerate, and valerate were significantly reduced. The dominant bacteria communities at the phylum level were Firmicutes, Proteobacteria, Bacteroidetes, and Spirochaetes. B. zhangzhouensis and B. altitudinis could convert NH4+-N to NO3--N, and A. pittii could transfer H2S to SO42-. This study revealed that bacteria deodorant can reduce the concentrations of NH3, H2S, and VFAs in pig feces and increase those of NH4+, NO3-, and SO42- and has excellent potential in deodorizing livestock and poultry feces composting.
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Affiliation(s)
- Changning Li
- Key Laboratory of Grassland Ecosystem, Ministry of Education, Lanzhou, 730070 Gansu, China; College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Chen Zhang
- College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Fu Ran
- College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Tuo Yao
- Key Laboratory of Grassland Ecosystem, Ministry of Education, Lanzhou, 730070 Gansu, China; College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China.
| | - Xiaojun Lan
- Agricultural College, Anshun University, Anshun 561000, Guizhou, China
| | - Haiyun Li
- Collaborative Innovation Center for Western Ecological Safety, Lanzhou University, Lanzhou 730000, Gansu, China
| | - Jie Bai
- College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Yang Lei
- College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Ze Zhou
- College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
| | - Xiaoning Cui
- College of Grassland Science, Gansu Agricultural University, Lanzhou 730070, Gansu, China
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Xu Y, Qi F, Yan Y, Sun W, Bai T, Lu N, Luo H, Liu C, Yuan B, Sheng Z, Liu T. The interaction of different chlorine-based additives with swine manure during pyrolysis: Effects on biochar properties and heavy metal volatilization. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 169:52-61. [PMID: 37406504 DOI: 10.1016/j.wasman.2023.06.023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 04/22/2023] [Accepted: 06/15/2023] [Indexed: 07/07/2023]
Abstract
Poor properties and high concentrations of heavy metals are still major concerns of successful application of animal manure-derived biochar into the environment. This work thus proposed to add chlorine-based additives (Cl-additives, i.e., CaCl2, MgCl2, KCl, NaCl, and PVC, 50 g Cl/ kg) to improve biochar properties and enhance heavy metal volatilization during swine manure pyrolysis. The results showed that the addition of CaCl2 could improve the retention of carbon (C) by up to 13.1% during pyrolysis, whereas other Cl-additives had little effect on it. Moreover, CaCl2 could enhance the aromaticity of biochar, as indicated by lower H/C ratio than raw biochar. Pretreatment with CaCl2, MgCl2 and PVC reduced phosphorus (P) solubility but increased its bioavailability via the formation of chlorapatite (Ca5(PO4)3Cl). The CaCl2 was more effective for enhancing the volatilization efficiency of heavy metals than other Cl-additives, except for Pb that tended to react with the generated Ca5(PO4)3Cl to form more stable and less volatile Pb5(PO4)3Cl. However, high pyrolysis temperature (900℃) was essential for CaCl2 to simultaneously decrease the bioavailability of heavy metals. Our results indicated that co-pyrolysis of swine manure with CaCl2 is a promising strategy to increase C retention, P bioavailability, and volatilization of heavy metals, and, at higher temperature, reduce the bioavailability of biochar-born heavy metals.
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Affiliation(s)
- Yonggang Xu
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake/ Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai'an 223300, China
| | - Fangjie Qi
- Nanjing Institute of Soil Science, Chinese Academy of Sciences, 71 Beijing East Road, Nanjing, Jiangsu Province 210008, China; Global Centre for Environmental Research, Advanced Technology Center (ATC) Building, Faculty of Science, The University of Newcastle, University Drive, Callaghan, NSW 2308, Australia.
| | - Yubo Yan
- School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an 223300, China
| | - Weimin Sun
- 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 510650, China
| | - Tianxia Bai
- School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an 223300, China
| | - Nan Lu
- School of Life Sciences, Huaiyin Normal University, Huai'an 223300, China
| | - Hong Luo
- School of Life Sciences, Huaiyin Normal University, Huai'an 223300, China
| | - Cong Liu
- School of Life Sciences, Huaiyin Normal University, Huai'an 223300, China
| | - Biao Yuan
- School of Life Sciences, Huaiyin Normal University, Huai'an 223300, China
| | - Zhenhuan Sheng
- School of Chemistry and Chemical Engineering, Huaiyin Normal University, Huai'an 223300, China
| | - Tingwu Liu
- Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake/ Collaborative Innovation Center of Regional Modern Agriculture & Environmental Protection, Huaiyin Normal University, Huai'an 223300, China
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Dal Pozzo A, Capecci S, Cozzani V. Techno-economic impact of lower emission standards for waste-to-energy acid gas emissions. WASTE MANAGEMENT (NEW YORK, N.Y.) 2023; 166:305-314. [PMID: 37207591 DOI: 10.1016/j.wasman.2023.05.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 04/26/2023] [Accepted: 05/08/2023] [Indexed: 05/21/2023]
Abstract
Acid gas removal is one of the main drivers of operating costs in the flue gas cleaning lines of waste-to-energy (WtE) plants. In the light of updated technical and normative references, such as the revised Best Available Technology reference document for waste incineration in the EU, plants are required to comply with increasingly lower emission limit values (ELV). In the case of existing WtE plants, this requires selecting the appropriate option among three alternatives: intensification of current operations, installation of additional equipment (retrofitting) or substitution of equipment (revamping). The identification of the most cost-effective solution to meet the new ELVs is thus paramount. In the present study, a comparative techno-economic assessment is performed with reference to the relevant options available to WtE plants equipped with a dry acid gas treatment system, explicitly taking into account the influence of several technical and economic variables by a sensitivity analysis. The results show that retrofitting based on furnace sorbent injection is a competitive option especially in the presence of high acid gas loads in the flue gas. Despite the high investment cost, revamping based on conversion to wet scrubbing can also reduce the overall cost of treatment compared to intensification, but only if no constraints are present on flue gas temperature downstream of the acid gas treatment. If flue gas reheating is needed, e.g., for the compatibility with a downstream DeNOx treatment or to avoid plume visibility at stack, the associated costs make revamping not competitive with retrofitting or intensification. Sensitivity analysis confirms that these findings are robust even in presence of relevant variations in cost entries.
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Affiliation(s)
- Alessandro Dal Pozzo
- LISES - Laboratory of Industrial Safety and Environmental Sustainability - DICAM - University of Bologna, via Terracini n.28, 40131 Bologna, Italy
| | - Sarah Capecci
- LISES - Laboratory of Industrial Safety and Environmental Sustainability - DICAM - University of Bologna, via Terracini n.28, 40131 Bologna, Italy
| | - Valerio Cozzani
- LISES - Laboratory of Industrial Safety and Environmental Sustainability - DICAM - University of Bologna, via Terracini n.28, 40131 Bologna, Italy.
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