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1.
Metallurgical production is the largest polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) emission source in China. However, PCDD/F monitoring and research are rarely conducted on primary metallurgical production. In this study, a demonstration primary copper smelter in China was selected to investigate PCDD/F characteristics and control. Samples were collected from major PCDD/F release points in the smelter process (fly ashes and waste water sludge). Specific analysis of PCDD/F congeners was carried out using a high resolution gas chromatography/high resolution mass spectrometry method. The results showed that PCDD/Fs might be unintentionally produced in the primary copper smelter processes, with sample concentrations of 180–6110 pg/g dry wt; highly chlorinated PCDD/F homologues were predominant. The toxicity of all the samples was calculated to be 120 pg WHO TEQ/g, fly ashes from the refining process furnaces air pollution control device and sludge were hazardous waste with higher PCDD/F toxicity. Both precursor formation and de novo synthesis were found to contribute to PCDD/F formation in the smelter process. PCDD/F characteristics and formation were compared with reported secondary copper smelters. Life-cycle control of PCDD/F was proposed for retrofitting of this smelter and for similar plants in China's primary copper production sector, including control at the PCDD/F formation, removal and disposal stages.  相似文献   

2.
Soxhlet extraction of polychlorinated dibenzo‐p‐dioxins/dibenzofurans (PCDD/F) from sediment was studied using a designed experimental set‐up. Three variables were studied: three solvent combinations n‐hexane/methanol, dichloromethane/acetone and toluene/methanol; two extraction times, 8 and 16 h, and addition of bulk substances (sodium carbonate). The extraction efficiency was almost identical in all extractions, with the exception of extraction where toluene/ methanol was combined with sodium carbonate. In these samples a major effect was observed, due to formation of Hx‐, Hp‐ and OCDD isomers. Composition of formed PCDD was similar to PCDD isomers found in pentachlorophenol products.  相似文献   

3.
不同垃圾焚烧炉产生的PCDD/Fs和PCBs同类物的分布   总被引:2,自引:1,他引:2  
要应用高分辨气相色谱一质谱联用技术,测定了3种垃圾焚烧炉产生的飞灰中17种PCDD/Fs和12种共平面PCBs的浓度及毒性当量,比较了PCDD/Fs和PCBs同类物分布的差异.结果表明,流化床焚烧炉和炉排焚烧炉产生的PCDD/Fs多于PCBs,而气化熔融焚烧炉产生的PCBs多于PCDD/Fs;产生的PCBs对总毒性当量的贡献都比较小;3种焚烧炉产生的PCDD/Fs同类物具有相似的浓度分布;流化床焚烧炉和炉排焚烧炉产生的PCBs同类物具有相似的浓度分布,而气化熔融焚烧炉产生的PCBs同类物分布与其他两种焚烧炉差别较大.  相似文献   

4.
Different mechanisms operating downstream from high temperature processes lead to the formation of polychlorinated dibenzo(p) dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Independent of the level of concentration, these mechanisms lead to comparable PCDD/F patterns, as has been observed from the proportion of single congeners to the total of 17 2,3,7,8-Cl-substituted congeners or to the individual homologous groups related to the sum of the homologous tetra to octa CDD/F groups. A comparison of these so-called “combustion profiles” with the congeners Heats of Formation (HoF), as calculated via semiempirical molecular orbital methods, may provide an idea of the course of thermodynamical forced reaction.  相似文献   

5.
Different mechanisms downstream from high temperature processes lead to the formation of polychlorinated dibenzo(p) dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Independent from any concentrations, these mechanisms cause comparable PCDD/F patterns, the percentage proportion of single congeners or homologous groups related to the total of 17 2,3,7,8-Cl-substituted congeners or with respect to the sum of the homologous groups tetra to octa CDD/F. The characteristics of these so-called “combustion profiles” can help to interpret corresponding data from burning and melting facilities, such as municipal waste incinerators, coal power plants, sintering plants, metal finishing facilities, cement kilns, crematoria, hazardous waste incinerators and landfill gas burners  相似文献   

6.
In Nuremberg (Germany), each year about 25,000 tons (dry matter) of sewage sludge are obtained as by-product of waste water treatment. The digested sludge consists of 96% water. Until 1992 it was thermally stabilized using the Porteous procedure: the sludge was heated in an autoclave up to a temperature of 180–200 °C at a pressure of 28 bar. After pressure reduction and moving to a thickener, a substantial part of the liquid could be removed. After running through a chamber filter, the sludge contained only about 50% dry matter. This treatment does not only remove water; organic matter is also degraded or evaporated. Between November 1991 and May 1992, the sludge was analyzed four times before and after the drying process and examined for heavy metals (Pb, Cd, Cr, Cu, Ni, Hg, Zn), polychlorinated biphenyls (PCB) and PCDD/F. The concentration of heavy metals and PCB (related to dry matter) increased by a faktor of 1.3 after the drying process. This effect may be explained by the decrease of organic matter during drying. In the case of PCDD/F, the ITQ increased by a factor of 3.2, for some congeners even by a factor of 8. The only explanation can be that during thermal conditioning PCDD/F is formed by precursors as chlorophenols. This formation is probably catalyzed by metals as copper or nickel and sped up by the higher temperatures.  相似文献   

7.
● Heavy metals and organic toxins may persist in legacy sites for a long time. ● Contaminants pose potential harms to the nearby community (HI > 1). ● PCDD/Fs had the risk of endocrine disruption and reproductive risk. ● Further intervention is needed to reduce pollution and related risks. Informal electronic-waste (e-waste) recycling sites pose substantial health risks to surrounding environments and populations, yet they are not properly regulated. In this study, the soil levels of copper, lead, cadmium, eight polybrominated diphenyl ethers (PBDEs), and 18 polychlorinated dibenzo-dioxins/furans (PCDD/Fs) were measured at two e-waste recycling sites in South China between 2014 and 2019. Both sites have been abandoned for natural restoration. Our results indicate that the mean Cd and PCDD/F levels at Site A in 2019 were higher than those recommended by current safety guidelines. Meanwhile, the highest exposure among children was 1.36 × 10−2 mg/(kg·d) for Cu, followed by 5.05 × 10−3 mg/(kg·d) for Pb, 9.71 ng/(kg·d) for PBDEs, and 6.82 ng TEQ/(kg·d) for PCDD/Fs. Children were at elevated risk for health problem posed by Pb and Cu exposure at both sites (hazard quotient > 1) and by PCDD/Fs at Site A. Further risk assessment was conducted on the target organs and endpoints of heavy metals and PCDD/Fs. The hazard index (HI) for the target organ mixed-risk of heavy metals was high (HI = 1.27), as was that of PCDD/Fs (HI = 1.66), which can disrupt endocrine function and pose a risk of reproductive toxicity in children. Owing to incomplete cleaning, contaminants persist in soils over long periods and may harm nearby environments and communities. Our study demonstrates that heavy metal, PBDE, and PCDD/F contamination have not yet been remediated, and intervention is needed to reduce pollution and associated risks in areas affected by e-waste.  相似文献   

8.
This article investigates available environmental data from measurements of the everywhere present contaminants polychlorinated dibenzo‐p‐dioxins and dibenzofurans (PCDD/F) in dated trends in sediment, soil and herbage from locales in Europe and North America. The PCDD/F data are examined in relation to potential major PCDD/F sources based on volume: wood and coal, example of natural combustion; pentachlorophenol (PnCP), example of chlorinated aro‐matics; and polyvinyl chloride (PVC) pyrolysis, example of chlorinated aliphatic. Collected PCDD/F data of congener sums and 2, 3, 7, 8‐substituted congener (PCDD/F profiles) have been investigated with multivariate methods: principal component analysis (PCA) and partial least squares projection to latent structures model (PLS). The results show that PCDD/F data from 12 locales can be separated in one to three independent profiles. Normally one profile is related to the PCDD/F found in PnCP and another to combustion. A subtype of the ‘PnCP’ and ‘combustion’ profiles indicates PCDD/F contributions from PVC‐related combustions. The environmental profiles exhibit some differences from the suggested sources. The relatively unprotected PCDD/F related to PnCP is suggested to have passed photolytic and/or thermal dechlorinations. Lower‐chlorinated congeners in environmental profiles related to combustion appear to have been influenced by environmental distribution processes. PCDD/F data before industrial production of chlorinated organics have only limited similarity to PCDD/F in technical PnCP profiles; an average 4.6% of the PCDD/F is related to PnCP. This suggests that PnCP similarity in recent deposition profiles cannot be a result of environmental transformation. The average proportion of PnCP‐related PCDD/F profile in recent depositions is 35% with North America high (average 57%) and Europe low (average 24%).  相似文献   

9.
In order to better understand the environmental behaviors of persistent organic pollutants, the characteristics of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were investigated in twenty-three soil/sediment samples from Baiying City, Northwest China, in 2008. The possible sources and potential health risk of PCDD/Fs were also discussed. The concentrations of PCDD/Fs in nineteen soil samples varied between 20.13 and 496.26 pg/g dry weight (dw.), with an average value of 125.59 pg/g dw. The highest International Toxic Equivalent (I-TEQ) of PCDD/Fs (8.34 pg/g dw.) in soil was found at sample S1 collected from proximity to a copper metallurgy plant. The concentrations of PCDD/Fs in four sediment samples ranged from 37.69 to 491.49 pg/g dw., with an average value of 169.95 pg/g dw. The highest I-TEQ of PCDD/Fs (8.56 pg/g dw.) in sediment was found at sample S12 collected from the East big ditch with waste water discharged into the Yellow River. The results indicated that PCDD/Fs contamination of soil/sediment is originated from three sources: chlorine-containing chemicals, non-ferrous metal industrial PCDD/Fs emission and coal burning. The health risk exposure to PCDD/Fs through soil, dust ingestion and dermal absorption ranged from 0.0006 to 0.0134 pg/kg/day Word Health Organization’s toxic equivalent in 1998 (WHO1998-TEQ) with mean values 0.0032 pg WHO1998-TEQ for adults and varied between 0.0012 and 0.0256 pg/kg/day WHO1998-TEQ with mean values 0.006 pg/kg/day WHO1998-TEQ for children, respectively. These results indicated that health risk of PCDD/Fs for children should be paid more attention.  相似文献   

10.
Soil samples were taken from residential gardens, grasslands and forests at 22 locations in Marsberg, North Rhine-Westphalia, and analyzed for PCDD/F. Sampling was concentrated on the vicinity of a former copper smelter where copper waste material (calledKieselrot) was deposited and emissions from former stacks contaminated a large land area. Maximum PCDD/F-concentrations were 407 ng TE GBA/kg dm in garden soil (0–30 cm depth), 98 ng TE BGA/kg dm in agricultural grassland (0–10 cm depth), 227 ng TE BGA/kg dm in wasteland, and up to 8073 ng TE BGA/kg dm in forest soils. PCDD/F-levels in soil decreased with increasing distance from the former sources providing a large historic emission problem, apart from the still existing kieselrot waste site. Ash residues from former flue gas duct showed up to 2,4 mg TE BGA/kg dm. PCDD/F-concentrations in vegetable samples from highly contaminated garden soils and grass from agricultural grassland were found to be relatively low in relation to soil values. PCDD/F-levels in salad showed a mean of 2,2 ng TE BGA/kg dm while grass concentrations were <6 ng TE BGA/kg dm. Thus, no correlation was found between soil and vegetation values with the exception for carrot roots where obviously a small transfer of PCDD/F between the two media took place. PCDD/F-content in grass taken over the vegetation period showed a tendency to increase toward the end of the growing season, which is probably related to changes in the dry matter yield over the season. No correlation was found in general between soil, grass and milk PCDD/F contents when all samples were taken from the same grassland. PCDD/F-concentrations in milk ranged between 0,6 and 1,1 pg TE BGA/g milkfat and were thus in the same range as consumer milk in the Federal Republic of Germany. PCDD/F in needles from conifers showed a clear relationship with respect to distance from the former waste site. The relatively high levels in conifer needles [36 ng TE BGA/kg dm] were obviously due to sporting activities (i.e. motocross racing where contaminated material was resuspended and deposited on surrounding trees).  相似文献   

11.
Present knowledge assumes that different mechanisms acting downstream in high temperature processes lead to the formation of polychlorinated dibenzo(p)dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Concerning the 17 2,3,7,8-Cl-substituted PCDD/F congeners in particular, there is new evidence for a single-step reaction type (recently reported in this publication series, of. also parts 1 and 2). A formation based on a combination of the several mechanisms, which have been proposed and discussed since 1985, becomes more and more unlikely. Qualitatively the PCDD/F formation downstream from high temperature processes depends rather on a thermodynamically forced single reaction step, and on pure statistical distribution quantitatively. This may be a new ‘Thermostat Synthesis’ instead of ‘de novo’.  相似文献   

12.
《Ecological modelling》2005,184(1):83-101
The model presented in this paper integrates a large amount of recent and ad hoc collected data concerning environmental contamination from micropollutants in the lagoon of Venice. This model represents the first step in setting up of an ecotoxicological model for the Venice lagoon, to simulate fate of contaminants from abiotic matrices to organisms. Distribution and partitioning of organic and inorganic contaminants are modelled by a two-dimensional model, based both on deterministic and empirical submodels and adapted to a large spectrum of different substances (polychlorinated dibenzo-dioxins/polychlorinated dibenzo-furans (PCDD/F), polychlorinated biphenyls (PCBs), heavy metals). The model was successfully calibrated on a wide set of experimental data. Sensitivity analysis showed that the model is generally not very sensible to parameters values but it is sensible to external conditions (e.g., pollutants loads). Distribution of dissolved and total concentrations of contaminants was obtained for a series of PCDD/F and PCBs congeners and for eight heavy metals. These distributions represent integrated information on ecosystem health, complementary to monitoring data and they are useful to be used for comparisons with various water quality criteria. Simulation scenarios under different external conditions are proposed as examples of use of the model for management purposes.  相似文献   

13.
25 food samples, 5 mother’s milk specimens, 4 dust samples, and 16 textiles were analysed for phthalic acid esters. Phthalic acid esters were detected in all samples, with di (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DBP) being the most abundant phthalates. Raw milk samples revealed average concentrations of total phthalate of 0.1 mg/kg. Retail milk did not contain higher loads than raw milk, even storing samples until their “best-before” date did not result in elevated levels. Skimmed milk was less contaminated than whole milk. The higher concentrations of DEHP and total phthalates in cream samples are due to their higher fat content. With concentrations up to 1.54 mg/kg, ground hazelnuts, almonds, and nutmeg in plastic packagings showed relatively high levels. In infant food, only traces of DEHP and DBP could be found while other phthalic acid esters were not detectable. The mother’s milk samples also exhibited only low amounts of approx. 0.1 mg/kg, thus indicating that there is no accumulation of phthalate esters in the human body. Extraordinarily high concentrations were found in dust samples; with the levels ranging from 300 to 5370 mg/kg and DEHP being the major compound. This leads to the conclusion that the air path must play a considerable role in the transfer of phthalic acid esters. As dust contains considerable amounts of textile fibres, textiles were also included in the investigation. The phthalic ester levels in the textile samples ranged from 3.42 to 34.44 mg/kg. Therefore, the high phthalate contaminations of dust cannot be explained by textile fibres.  相似文献   

14.
Spatial distribution, seasonal variation and potential inhalation risks of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) were investigated in the atmosphere of Beijing, using passive air samplers equipped with polyurethane foam disks. Concentrations of ΣPCDD/Fs, ΣPCBs and ΣPBDEs ranged from 8.4 to 179 fg WHO2005-TEQ/m3, 38.6–139 and 1.5–176 pg/m3, respectively. PCDFs showed higher air concentrations than those of PCDDs, indicating the influence of industrial activities and other combustion processes. The non-Aroclor congener, PCB-11, was detected in air (12.3–99.4 pg/m3) and dominated the PCB congener profiles (61.7–71.5% to ∑PCBs). The congener patterns of PBDEs showed signatures from both penta-BDE and octa-BDE products. Levels of PCDD/Fs, PCBs and PBDEs at the industrial and residential sites were higher than those at rural site, indicating human activities in urban area as potential sources. Higher air concentrations of PCDD/Fs, PCBs and PBDEs were observed in summer, which could be associated with atmospheric deposition process, re-volatilization from soil surface and volatilization from use of technical products, respectively. Results of inhalation exposure and cancer risk showed that atmospheric PCDD/Fs, dioxin-like PCBs and PBDEs did not cause high risks to the local residents of Beijing. This study provides further aid in evaluating emission sources, influencing factors and potential inhalation risks of the persistent organic pollutants to human health in mega-cities of China.  相似文献   

15.
After the discovery of high dioxin levels (>100 000 ng TE BGA/kg) in copper slag (Kieselrot) from a specific chlorinating roasting process performed in Marsberg, human milk samples from mothers living in Marsberg were analyzed for polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF) and other pollutants. PCDD/F levels in all samples were comparable with levels in human milk samples from other locations in the Federal Republic of Germany. An increase in congeners, especially of those predominating in ?Kieselrot“, could not be measured. Although several thousand tons of dioxin contaminated copper slag still lie on the slagheap, a higher burden in human milk from Marsberg could not be observed.  相似文献   

16.
草浆漂白过程中二噁英类生成机理探讨   总被引:1,自引:0,他引:1  
本文以氯苯、氯酚、二苯并二噁英(DBD)和二苯并呋喃(DBF)为PCDD/Fs前生体,模拟工业草浆漂白条件,探讨了次氯酸盐和氯气漂白苇浆过程中二噁英类的生成机制,研究表明,在苇浆中加入二噁英类前生体如DBD/F,其氯化产物与在木浆中有所区别,在实验条件下,二噁英类的生成量分别为:15μg PCDDs·mg~(-1)DBD。1.5μg PCDFs·mg~(-1)DBF。  相似文献   

17.
危险废物焚烧设施二噁英类排放特征及周边土壤污染调查   总被引:2,自引:0,他引:2  
调查了13座不同类型的危险废物焚烧设施及二噁英类排放模式及部分设施土壤的污染水平.结果表明,排放浓度同焚烧处理量没有显著的关系.4—6氯代PCDD/Fs和7—8氯代PCDD/Fs呈现出了不同的排放特征.4—6氯代PCDF/PCDD比值为60.58±1.98(95%置信区间),较通用的总PCDF/总PCDD比值更适于描述危险废物焚烧设施二噁英排放的特征.使用PCA及聚类分析方法将设施排放模式归类为3种模式.分布模式同焚烧设施炉型、处理量以及尾气处理方式等因素相关性并不显著.2,3,4,7,8PeCDF对I-TEQ的贡献为35%—45%,并与I-TEQ具有很高的相关性.厂区土壤中二噁英浓度水平约为8—14ngI-TEQ.kg-1,周边土壤浓度为1—4ngI-TEQ.kg-1左右,均处于较低水平,调查设施周边土壤的使用目前尚无明显风险.危险废物设施对周边土壤的环境风险需要进一步评估.  相似文献   

18.
北京市农业区不同使用类型土壤中二噁英类分析   总被引:1,自引:0,他引:1  
2005年6—7月采集了北京市农业区不同使用类型土壤样品24个,分别为蔬菜地8个、粮地8个、果园地8个,采用高分辨气质联机对17种二噁英类进行了分析.结果表明:所有样品中二噁英浓度范围为,0.26—5.74(平均值为1.51)pgI-TEQ.g-1;蔬菜地浓度范围为,0.26—5.62(平均值1.75)pgI-TEQ.g-1;粮地浓度范围为,0.45—5.74(平均值2.02)pgI-TEQ.g-1;果园地浓度范围为,0.34—2.02(平均值0.73)pgI-TEQ.g-1;三种类型中粮食地浓度最高,其次为蔬菜地,果园地浓度最低.与国外农业区土壤中的二噁英浓度相比而言,北京市相对较低.所有样品中,样品8和16浓度异常高,但是8.3%(2:24)的高浓度样品数并不代表对人体有害.由于样品24处于垃圾焚烧炉旁边,也对此进行了详细的分析.样品中二噁英类物质形态分布出现了极大的离散性,这表明农田土壤中二噁英可能是多种因素综合作用的结果,例如:除草剂的使用、秸秆等固体废弃物的焚烧、汽车尾气排放等.  相似文献   

19.
Surfaces of many sports fields, playgrounds and paths in Germany are covered with red slag ?Kieselrot”. Kieselrot is extremely high contaminated by polychlorinated dibenzodioxines and dibenzofurans. Mean PCDD/F-concentration in surface layers of 35 locations in Hessen is 45 500 ng I-TE/kg. PCDD/F-contents range from 1 000 to 250 ng I-TE/kg within 10 cm under surface layers and from 6 000 to 600 ng I-TE/kg in top soils of three metres wide peripheral areas. Concentration in subsoils is a function of depth (n=18, r=?0,741), concentration in topsoils of peripheral areas is a function of distance from large sports fields (n=14, r=?0,881) or small sportsfields (n=23, r=?0,742), respectively. A 15 metres wide and 10 centimetres deep peripheral area contains 0,8 g I-TE PCDD/F. The pollution of surroundings and further observations indicate that ?Kieselrot-areas” must be regarded as important dioxin sources.  相似文献   

20.
The sources and reservoirs of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF) in the city of Hamburg, Germany, in the year 1992 were identified and quantified combining analytical data of PCDD/PCDF with statistical data on annual fluxes of materials and products. Fluxes and amounts of PCDD/PCDF were estimated for the environmental compartments water, air, and soil. Dioxin emissions originating from industrial, commercial or private activities were also calculated. Together with the analysis of the specific regional nutrition data, the human exposurevia the various pathways could be determined. It could be shown that the total PCDD/PCDF intake of individuals in Hamburg was about the same as the national average. High annual fluxes of PCDD/PCDF connected with the trade of industrial products and the waste management and disposal: system in Hamburg obviously had no influence on the human intake of PCDD/PCDF.  相似文献   

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