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Weidemann E, Buss W, Edo M, Mašek O, Jansson S. Influence of pyrolysis temperature and production unit on formation of selected PAHs, oxy-PAHs, N-PACs, PCDDs, and PCDFs in biochar-a screening study. Environ Sci Pollut Res Int 2018; 25:3933-3940. [PMID: 29119490 PMCID: PMC5811578 DOI: 10.1007/s11356-017-0612-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/24/2017] [Indexed: 05/07/2023]
Abstract
The influence of reactor type and operating conditions of the pyrolysis unit on the final concentration of toxic contaminants in biochar remains unclear. Therefore, we determined the concentrations of polycyclic aromatic hydrocarbons (PAHs), oxygenated polycyclic aromatic hydrocarbons (oxy-PAHs), nitrogen-containing polycyclic aromatic compounds (N-PACs), polychlorinated dibenzo-p-dioxins (PCDDs), and dibenzofurans (PCDFs) in biochars produced from three different feedstocks (softwood, wheat straw, and anaerobic digestate). Different scaled pyrolysis units (one batch and two continuous units) at two different temperatures (550 and 700 °C) were considered. The results revealed that the type of biomass had a significant influence on the PAH, oxy-PAH, and N-PAC content of the biochars. The configuration and type of the pyrolysis unit influenced only the wheat straw pyrolyzed at 550 °C. PCDDs and PCDFs occurred at very low levels in the biochars. In terms of PAH, PCDD, and PCDF content, the biochars assessed in this study represent a low risk to the environment, regardless of the temperature and type and size of the pyrolysis unit.
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Affiliation(s)
- Eva Weidemann
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Wolfram Buss
- UK Biochar Research Centre, School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Mar Edo
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden
| | - Ondřej Mašek
- UK Biochar Research Centre, School of GeoSciences, University of Edinburgh, Edinburgh, UK
| | - Stina Jansson
- Department of Chemistry, Umeå University, SE-901 87, Umeå, Sweden.
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Wang T, Chen T, Lin X, Zhan M, Li X. Emission and distribution of PCDD/Fs, chlorobenzenes, chlorophenols, and PAHs from stack gas of a fluidized bed and a stoker waste incinerator in China. Environ Sci Pollut Res Int 2017; 24:5607-5618. [PMID: 28035608 DOI: 10.1007/s11356-016-8221-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/07/2016] [Indexed: 06/06/2023]
Abstract
The concentrations, homologue, and congener profiles, as well as the gas/particle distribution of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs), chlorobenzenes (CBzs), chlorophenols (CPhs), and polyaromatic hydrocarbons (PAHs) from stack gas of two different municipal solid waste incinerators in China, were characterized. The incinerators were a stoker furnace incinerator equipped with the advanced air pollution control device (APCD) and a common circulating fluidized bed (CFB) furnace. The concentration of PCDD/Fs in the stack gas of the stoker incinerator ranged 0.011-0.109 ng international toxic equivalent factor (I-TEQ)/Nm3 and was below the current limit for PCDD/F emissions from the municipal solid waste incinerators (MSWIs) in China (0.1 ng I-TEQ/Nm3) in most of the cases. Moreover, the concentration of PCDD/Fs in the stack gas of the stoker incinerator was significantly lower than that of the CFB incinerator (0.734 to 24.6 ng I-TEQ/Nm3). In both incinerators, the majority of the total PCDD/F emissions (above 90%) ended up in the gas phase. 2,3,4,7,8-PeCDF, which occupied 24.3-43.6 and 32.5-75.6% of I-TEQ contribution in MSWIs A and B, respectively, was the most abundant congener. However, different types of incinerators and APCDs induced different congener and homologue distributions. The total concentration of CBzs from the stoker incinerator (0.05-3.2 μg/Nm3) was also much lower than that formed from the CFB incinerator (10.9-75.2 μg/Nm3). The phase distribution of CBzs followed the same pattern as with the PCDD/Fs. Moreover, the emission level of CBz was 100-1000 times higher than that of the PCDD/Fs, which determines the applicability of CBzs as indicators of PCDD/F emissions. High correlations between the emission concentrations of PCDD/Fs, TeCBz, and PCBz in specific ranges were revealed. Furthermore, high concentrations of CPhs (0.6-141.0 μg/Nm3) and PAHs (148.6-4986.5 μg/Nm3) were detected in the stack gases of MSWI B. In some cases, the concentrations were as high as the concentrations in the fumes exiting the boiler of one foreign stoker without flue gas purification indicating the abundance of CPh and PAH emissions in the stack gas of waste incinerators.
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Affiliation(s)
- Tianjiao Wang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Tong Chen
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China.
| | - Xiaoqing Lin
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Mingxiu Zhan
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
| | - Xiaodong Li
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, People's Republic of China
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Liao J, Buekens A, Olie K, Yang J, Chen T, Li X. Iron and copper catalysis of PCDD/F formation. Environ Sci Pollut Res Int 2016; 23:2415-2425. [PMID: 26416123 DOI: 10.1007/s11356-015-5437-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2015] [Accepted: 09/15/2015] [Indexed: 06/05/2023]
Abstract
The formation of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) was explored during de novo tests designed to compare the catalytic activity of copper (II) chloride (CuCl2) with that of iron (III) oxide (Fe2O3) and to test some synergistic effect between these two catalytic compounds. Both copper chloride (CuCl2) and iron oxide (Fe2O3) were earlier proposed as catalysts to explain the PCDD/F emissions from, e.g. municipal solid waste incineration (MSWI). In addition, haematite (Fe2O3) is the main iron ore and could be responsible for the typical iron ore sintering plant fingerprint. A total of nine model fly ash (MFA) samples were prepared by mixing and grinding of sodium chloride (NaCl), activated carbon and a powder matrix of silica (SiO2) with the selected metal compound(s). The conditions of these de novo tests were 1 h in duration, 350 °C in a flow of synthetic combustion gas (10 vol.% oxygen in nitrogen). The effect of Fe-Cu catalyst concentration on yield and distribution pattern of PCDD/F was systematically explored; three strongly differing ratios of [Fe]:[Cu] were considered (1:1, 10:1 and 100:1) to study the potential interactions of Fe2O3 and CuCl2 suggested earlier. The results show some slight rise of PCDD/F formed with raising iron concentration from 0 to 10.1 wt% (no Cu added; 0.1 wt% Cu), as well as strong surging of both amount and average chlorination level of PCDD/F when rising amounts of copper (0 to 1.1 wt%) are introduced. The resulting fingerprints are compared with those from sintering and from MSWI.
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Affiliation(s)
- Junhong Liao
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Alfons Buekens
- Formerly with Vrije Universiteit Brussel, Brussels, Belgium
| | - Kees Olie
- University of Amsterdam, Amsterdam, The Netherlands
| | - Jie Yang
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Tong Chen
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China
| | - Xiaodong Li
- State Key Laboratory of Clean Energy Utilization, Institute for Thermal Power Engineering, Zhejiang University, Hangzhou, 310027, China.
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Wu TW, Lee JW, Liu HY, Lin WH, Chu CY, Lin SL, Chang-Chien GP, Yu C. Accumulation and elimination of polychlorinated dibenzo-p-dioxins and dibenzofurans in mule ducks. Sci Total Environ 2014; 497-498:260-266. [PMID: 25129161 DOI: 10.1016/j.scitotenv.2014.07.106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 07/26/2014] [Accepted: 07/27/2014] [Indexed: 06/03/2023]
Abstract
In Taiwan, a food safety crisis involving a presence of high concentrations of dioxin residues in duck eggs occurred in 2004. The dioxin content in duck meat sampled from supermarkets was also reported to be substantially higher than in products from other farm animals. Despite increased awareness of the potential for contamination and exposure to dioxins, the accumulation and elimination of dioxins in ducks have not been well characterized. In the present study, mule ducks were fed capsules containing polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) for 14 days and the trial was continued for another 28 days without PCDD/Fs supplementation. Ducks were sacrificed on the 14th, 28th, and 42nd days from the beginning of administration and samples of abdominal fat, breast, and liver tissue were obtained. The concentrations of PCDD/Fs were analyzed in the samples to investigate their distribution and elimination in various duck tissues. The bioaccumulation of PCDD/Fs in ducks was found to be tissue-dependent. In the abdominal fat, the bioconcentration factor was negatively correlated with the degree of chlorination. Conversely, more chlorinated PCDD/Fs (hexa- or hepta-congeners) were associated with higher bioconcentration in the liver and breast tissue. In terms of the efficiency of PCDD/Fs elimination, the liver was found to be the fastest, followed by the breast and the abdominal fat. The clearance rate positively correlated with the degree of chlorination, as determined by comparing the apparent elimination rate constant (k) of PCDD/Fs in various tissues. Overall, lower k values observed in this study imply that mule ducks have a reduced clearance of PCDD/Fs in comparison with layer and broiler chickens.
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Affiliation(s)
- Ting-Wei Wu
- Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Jai-Wei Lee
- Department of Tropical Agriculture and International Cooperation, National Pingtung University of Science and Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Hsueh-Yen Liu
- Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Wei-Hsiao Lin
- Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Chun-Yen Chu
- Graduate Institute of Animal Vaccine Technology, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
| | - Sheng-Lun Lin
- Supermicro Mass Research and Technology Center, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan; Center for General Education, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan.
| | - Guo Ping Chang-Chien
- Supermicro Mass Research and Technology Center, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan; Department of Cosmetics and Fashion styling, Cheng Shiu University, No. 840, Chengcing Road, Niaosong Dist., Kaohsiung City 83347, Taiwan.
| | - Chi Yu
- Department of Animal Science, National Pingtung University of Science Technology, No. 1, Shuefu Road, Neipu, Pingtung 91201, Taiwan.
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Phan DNC, Jansson S, Marklund S. Effects of regional differences in waste composition on the thermal formation of polychlorinated aromatics during incineration. Chemosphere 2013; 93:1586-1592. [PMID: 24007615 DOI: 10.1016/j.chemosphere.2013.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/22/2013] [Revised: 07/30/2013] [Accepted: 08/05/2013] [Indexed: 06/02/2023]
Abstract
Two artificial wastes (A and B) whose contents reflect regional differences in municipal solid waste composition, were used to investigate the thermal formation of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), biphenyls (PCBs), and naphthalenes (PCNs) during incineration. Flue gas samples were simultaneously collected at three ports in the post-combustion zone corresponding to flue gas temperatures of 400, 300, and 200 °C. The combustion of Waste B, which had a higher chlorine and metal content than Waste A, produced greater levels of highly-chlorinated homologues, as demonstrated by a higher degree of chlorination. The total concentrations of PCDDs, PCDFs, PCBs, and PCNs formed in the combustion of both wastes increased as temperature decreased along the convector. There were no significant differences in total concentrations between Waste A and Waste B combustion at specific temperatures, with exception of PCDFs at 400 °C. Orthogonal Projections to Latent Structures Discriminant Analysis (OPLS-DA) modeling, used to evaluate the data for all compound groups, suggest that during flue gas quenching at temperatures of 400 °C low-chlorinated homologues are preferentially formed in the presence of copper, which is known to be a very active catalyst for this process. At 300 and 200 °C, the formation of highly-chlorinated homologues is favored.
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Wong TW, Wong AHS, Nelson EAS, Qiu H, Ku SYK. Levels of PCDDs, PCDFs, and dioxin-like PCBs in human milk among Hong Kong mothers. Sci Total Environ 2013; 463-464:1230-1238. [PMID: 22939609 DOI: 10.1016/j.scitotenv.2012.07.097] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Revised: 07/02/2012] [Accepted: 07/30/2012] [Indexed: 06/01/2023]
Abstract
Dioxins are a family of persistent organic pollutants (POPs) listed under the Stockholm Convention, and include PCDDs, PCDFs, and dioxin-like PCBs. These toxic chemicals are carcinogenic, widely dispersed, and have long half-lives. They have contaminated the food web and, being fat-soluble, accumulate in adipose tissues and milk in the human body. To assess human exposure, we collected breast milk samples from 137 first-time mothers recruited from around Hong Kong. Samples were analysed by HRGC-HRMS in four pools, according to the subject's age and length of residency. Exposure was related to age, duration of stay, and possibly diet. Generally, older mothers, and mothers with a longer stay in Hong Kong, had higher levels of dioxins in their milk. This pattern was clearest for the PCBs, although deviations were observed for some of the PCDD/Fs. Mean concentrations, measured per gram of lipid weight in terms of WHO toxic equivalents (WHO-TEQs), were 7.48 pg/g for PCDD/Fs and 3.79 pg/g for PCBs, giving a total of 11.27 pg/g for PCDD/Fs and PCBs combined. Compared to an earlier Hong Kong study we conducted in 2002, the mean WHO-TEQ values in our latest findings were about 9% lower overall for PCDD/Fs and 19% lower for PCBs, with the mean total WHO-TEQ for PCDD/Fs and PCBs being around 13% lower in this study. This indicates a general declining trend in the levels of POPs in Hong Kong. However, our levels were still high when compared to those in some other Asian-Pacific countries. More stringent policies on reducing and eliminating POPs should help to lower these. Continued surveillance for POPs in human milk, as well as in common foodstuffs, will provide us with important information on human exposures that will be necessary for tracking our progress, and making future health risk assessments.
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Affiliation(s)
- Tze Wai Wong
- School of Public Health and Primary Care, The Chinese University of Hong Kong, Prince of Wales Hospital, Sha Tin, New Territories, Hong Kong
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