Chlorinated and Brominated Polycyclic Aromatic Hydrocarbons from

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Chlorinated and Brominated Polycyclic Aromatic Hydrocarbons from Metallurgical Plants Yang Xu, Li Li Yang, Minghui Zheng, Rong Jin, Xiaolin Wu, Cui Li, and Guorui Liu Environ. Sci. Technol., Just Accepted Manuscript • DOI: 10.1021/acs.est.8b01638 • Publication Date (Web): 06 Jun 2018 Downloaded from http://pubs.acs.org on June 7, 2018

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Environmental Science & Technology

1

Chlorinated

and

Brominated

Polycyclic

Aromatic

2

Hydrocarbons from Metallurgical Plants

3

Yang Xu†,‡, Lili Yang†,‡, Minghui Zheng†,‡, Rong Jin†,‡, Xiaolin Wu†,‡, Cui Li†,‡,

4

Guorui Liu†,‡,*

5

†

6

Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box

7

2871, Beijing 100085, China

8

‡

University of Chinese Academy of Sciences, Beijing 100049, China

9

*

Corresponding author. E-mail: [email protected]

State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research

10

1

ACS Paragon Plus Environment


11

ABSTRACT

12

In this study, we investigated several metallurgical industries, including iron ore

13

sintering, secondary aluminum smelting, and secondary lead smelting, as potential

14

sources of Cl-PAHs and Br-PAHs. Stack gas emissions of 19 Cl-PAH and 19 Br-PAH

15

congeners from the investigated metallurgical plants were in the ranges of 68.3–156.3

16

ng Nm−3 and 2.9–13.5 ng Nm−3, respectively. Cl/Br-PAHs in ambient air surrounding

17

the investigated metallurgical plants were also quantified, and the ranges were 7.0–

18

554 pg m−3 for Cl-PAHs and 3.0–126 pg m−3 for Br-PAHs. Toxic equivalent (TEQ)

19

concentrations of Cl-PAHs and Br-PAHs in the ambient air samples were in the

20

ranges of 0.03–3.61 pg TEQ m−3 and 0.001–0.23 pg TEQ m−3, respectively. These

21

TEQs were slightly higher than or comparable to those of dioxins and dioxin-like

22

compounds. Congener profiles of Cl-PAHs emitted from iron ore sintering, secondary

23

aluminum smelting, and secondary lead smelting facilities were clarified and their

24

congener profiles were obviously different from that from waste incinerators.

25

Comparisons of Cl/Br-PAH congener profiles between surrounding air samples and

26

stack gas emissions indicated that metallurgical emissions affected the surrounding

27

environment to some extent.

28 29

2


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TOC ART

31 32

3



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INTRODUCTION

34

Chlorinated and brominated polycyclic aromatic hydrocarbons (Cl/Br-PAHs)

35

with one or more chlorine and bromine atoms as substituents on the aromatic rings (>

36

3), are of increasing concern because they are ubiquitous in the environment and have

37

adverse health effects. Studies on the toxicities of these halogenated compounds have

38

revealed that they have similar toxicity to dioxins, and induce aryl hydrocarbon

39

receptor (AhR)-mediated activities, as confirmed by a yeast assay.1 Moreover, Cl/Br-

40

PAHs are readily accumulated in biological tissues as they have high lipophilicity,2

41

and show higher toxicities than their parent PAHs.1, 3, 4 5-11

42

Cl/Br-PAHs have been detected in a wide variety of environmental samples,

43

such as urban air, snow, tap water, and surface sediments.12-17 Identification and

44

quantification of various sources of Cl/Br-PAHs is the first step to control their source

45

emissions and reduce environmental loads and human risks. However, previous

46

studies have only focused on the levels and profiles of Cl/Br-PAHs in flue gas, fly

47

ash, and bottom ash samples from waste incinerators and secondary copper

48

smelters.18-20,21 The conditions favoring the formation of Cl/Br-PAHs might be similar

49

to those for unintentional persistent organic pollutants (POPs). Therefore, ferrous and

50

non-ferrous metal smelting processes that use conditions conducive to unintentional

51

halogenated organic pollutant formation could be potential sources of Cl/Br-PAHs.

52

However, the Cl/Br-PAH emissions from several important metallurgical industries,

53

including iron ore sintering, secondary aluminum smelting, and secondary lead

54

smelting, have never been quantified. 4


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During the industrial thermal processes of iron ore sintering, secondary

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aluminum, and secondary lead smelting, fuel (coal, natural gas, or coke) acts as a

57

carbon source to form organic contaminants and their precursors. Organic impurities,

58

such as plastics (e.g., polyvinyl chloride), paints, and solvents, contained in feed

59

materials (e.g., iron ore, aluminum ingot, abandoned lead acid batteries, and lead

60

scrap for lead recycling) could provide halogens for Cl/Br-PAH formation. Finally,

61

ferrous and non-ferrous metals might catalyze Cl/Br-PAH formation at appropriate

62

temperatures in the cooling stages. Many studies have confirmed that large quantities

63

of traditional halogenated aromatic pollutants, such as dioxins and polychlorinated

64

biphenyls (PCBs), are emitted from these industrial sources.22-27 There are thousands

65

of sinter plants and smelters operating in China, and millions of tons of metal and

66

alloy are manufactured each year. Therefore, these industrial activities are believed to

67

be potential important sources of Cl/Br-PAHs. Identification and characterization of

68

the emissions of Cl/Br-PAHs from those metallurgical industries can be used to

69

compile emission inventories, reduce source emissions, and decrease environmental

70

and human exposures.

71

In this first field study, stack gas samples were collected from typical

72

metallurgical plants carrying out iron ore sintering, secondary aluminum smelting,

73

and secondary lead smelting. The samples were analyzed by isotope dilution high

74

resolution gas chromatography combined with high resolution mass spectrometry

75

(HRGC/HRMS). These industries were evaluated as sources of Cl/Br-PAHs in the

76

emitted stack gases. The congener profiles of Cl/Br-PAHs from these industrial 5



77

sources will provide important information for apportioning specific sources of Cl/Br-

78

PAHs in the environment or biota. Ambient air samples were also collected from the

79

investigated metallurgical plants or their surroundings and quantified, with the aim of

80

evaluating potential exposure to airborne Cl/Br-PAHs.

81

EXPERIMENTAL SECTION

82

Information on the investigated metallurgical plants and sample collection

83

Two iron ore sinter plants, two secondary aluminum smelters, and one secondary lead

84

smelter were selected as typical metallurgical plants for investigation in this study

85

(Table 1). To determine the atmospheric emission levels and profiles of Cl/Br-PAHs

86

from these metallurgical plants, three stack gas samples were collected from each

87

plant using an automatic isokinetic sampling system (Isostack Basic; Tecora, Italy).

88

The stack gas sampling system contained a heated prober, filter box filled with a

89

quartz fiber filter, and a water-cooled XAD-2 adsorbent trap. The quartz filter

90

captured particle-bound contaminants, and the XAD-2 resin trapped gas phase

91

pollutants. Meanwhile, two ambient air samples were collected at each metallurgical

92

plant, or in the surrounding area, using high-volume air samplers (Echo Hi-Vol,

93

Tecora, Italy) at a flow rate of 0.24 m3 min−1 for 24 h according to US EPA method

94

TO-9A. The results were used to evaluate potential exposure and the impact of source

95

emissions in the areas surrounding the metallurgical plants. Polyurethane foam (ø 63

96

mm, length 76 mm, purified by accelerated solvent extraction with acetone and

97

hexane) was used to absorb organic pollutants from the gas phase, and clean quartz

98

fiber filters (ø 102 mm, baked in muffle furnace at 450°C for 6 h) were used to trap 6


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the particle phase. The oxygen contents in the stack gases from the five metallurgical

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plants were in the range of 7%–19%. Chlorine contents in fly ashes from iron ore

101

sintering, secondary aluminum smelting, and secondary lead smelting processes were

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2.36%, 4.53%, and 0.01%, respectively. The total organic carbon contents in fly ashes

103

from the iron ore sintering, secondary aluminum smelting, and secondary lead

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smelting processes were 1.32%, 14.9%, and 0.27%, respectively. 28

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Cl-PAHs and Br-PAHs (abbreviations and sources for Cl-PAH and Br-PAH congeners

106

are shown in Table S1) in the stack gas samples and ambient air samples were

107

analyzed by isotope dilution HRGC/HRMS. Before sample extraction, the samples

108

were spiked with stable isotope-labeled internal standards of Cl-PAHs and Br-PAHs

109

(13C6-1-chloropyrene,

110

bromobenz[a]anthracene were bought from Cambridge Isotope Laboratories

111

(Tewksbury, MA, USA); 13C6-9-chlorophenanthrene, 13C6-2-chloroanthracene, and 9-

112

bromophenanthrene-d9 were bought from Toronto Research Chemicals (Toronto,

113

Canada)). Then, the stack gas samples were Soxhlet-extracted into toluene, and the air

114

samples were extracted by accelerated solvent extraction with a 1:1 (v/v) mixture of

115

hexane and dichloromethane. The extract was cleaned using an active silica gel

116

column that had been prepared by baking at 450°C for 6.5 h. The eluate was

117

concentrated to approximately 50 µL on a rotary evaporator and under a gentle stream

118

of nitrogen gas in a vial. To evaluate the recoveries of the stable isotope-labeled

119

internal standards, the sample in the vial was spiked with an injection standard (13C6-

120

7,12-dichlorobenz[a]anthracene; Cambridge Isotope Laboratories) before analysis by

13

C6-7-chlorobenz[a]anthracene

7


and

13

C6-7-


121

HRGC/HRMS. A DB-5 MS capillary column (60 m × 0.25 mm × 0.25 µm, Agilent

122

Technologies, Cal. USA) was used for separation of Cl-PAH and Br-PAH congeners.

123

Selected ion monitoring mode was used, and the instrument had a resolution of

124

around 10 000. Parent PAHs in the samples were analyzed according to US CalEPA

125

Method 429, and the results were used to explore their relationships with Cl-PAHs

126

and Br-PAHs. A blank sample was analyzed with every batch of samples, and the

127

concentrations of target contaminants were below the limits of detection. The limit of

128

detection ranges was 2.94–94 pg for Cl-PAH congeners and 1.51–97 pg for Br-PAH

129

congeners in ambient air samples, and 1.54–62.6 pg for Cl-PAH congeners and 1.23–

130

34.9 pg for Br-PAH congeners in stack gas samples. The recovery ranges of the

131

labeled internal standards were 59%–118% in the stack gas samples and 64%–112%

132

in the ambient air samples, and were satisfactory according to the normal

133

requirements of trace analysis of POPs in environmental matrices using isotope

134

dilution HRGC/HRMS.

135

Assessment of exposure to Cl-PAHs and Br-PAHs by air inhalation

136

Preliminary estimates of the daily intakes of Cl-PAHs and Br-PAHs by air inhalation

137

for residents and workers in the areas surrounding the metallurgical plants were

138

calculated based on toxic equivalents (TEQs). TEQs for Cl/Br-PAHs can be expressed

139

as the products of the concentrations of the congeners multiplied by their relative

140

potencies (REPs). Unlike PCDD/Fs, which have toxic equivalent factors officially

141

assigned by World Health Organization (WHO), there are no internationally

142

recognized toxic equivalent factors for Cl/Br-PAHs. Therefore, previously reported 8


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AhR-mediated activities for Cl/Br-PAHs in a yeast assay system (YCM3 cell) were

144

adopted in this study. The REPs of individual Cl/Br-PAHs relative to benzo[a]pyrene

145

(BaP) (REPBaP) have been reported. In the YCM3 cell assay, the potency of 2,3,7,8-

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tetrachlorodibenzo-p-dioxin was 60 times higher than that of BaP.1, 3, 4 In the present

147

study, the following equation was used to estimate the TEQs of Cl/Br-PAHs in the

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stack gas and ambient air samples:

149

TEQ = ∑ /60,

150

where [ci] is the concentration of the Cl-PAH or Br-PAH congener. The REPs of only

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seventeen congeners of Cl/Br-PAHs have been published. Therefore, the actual

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toxicities of the Cl/Br-PAHs could be higher than the values estimated in this study.

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RESULTS AND DISCUSSION

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(1)

Stack gas emission levels and ambient air concentrations of Cl/Br-PAHs

155

from the metallurgical plants

156

Quantifying the stack gas emission levels of Cl/Br-PAHs from metallurgical plants is

157

a primary step for control of their source emissions and reduction of environmental

158

and health risks. The mass concentrations of the sum of nineteen (Σ19) Cl-PAHs and

159

Σ19Br-PAHs in the stack gases released from the investigated metallurgical plants

160

were measured (Table 2). The average stack gas concentrations of Cl-PAHs released

161

from the iron ore sinter plants, secondary aluminum smelters, and secondary lead

162

smelter were 119, 69.4, and 142 ng Nm−3, respectively. The mean concentrations of

163

Br-PAHs in the stack gas samples collected from the iron ore sinter plants, secondary

164

aluminum smelters, and secondary lead smelter were 6.5, 8.2, and 8.3 ng Nm−3, 9



165

respectively. Unexpectedly, the secondary lead smelting process emitted the highest

166

concentrations of Cl-PAHs and Br-PAHs, which was not consistent with the trends for

167

other chlorinated organic pollutants, including PCDD/Fs (0.9–155 ng Nm−3), PCBs

168

(0.2–7.1 ng Nm−3), and PCNs (11.4–394 ng Nm−3), observed in a previous study.29

169

Organic impurities in raw materials, and the technology and fuels used all play

170

important roles in the formation of unintentional POPs. A previous study found that

171

smelters that use coal, coke, and heavy oil as fuel had higher emission levels of

172

halogenated compounds than one that used natural gas.30 This is in agreement with

173

our results. Among the plants investigated in the present study, the secondary lead

174

smelter and iron ore sinter plants that used coke and coal as their main fuel showed

175

higher concentrations of Cl-PAHs and Br-PAHs in the flue gases than the secondary

176

aluminum smelters, which used natural gas. Thus, clean energy sources are important

177

for reducing the emissions of organic pollutants during metallurgical processes.

178

Ambient air samples collected from around the investigated metallurgical plants were

179

analyzed to evaluate potential exposure to airborne Cl/Br-PAHs. The highest

180

concentrations of Cl-PAHs were found in air samples collected near the iron ore sinter

181

plants (193–554 pg m−3). The Cl-PAH concentrations were slightly lower in the air

182

samples collected from around the secondary lead smelters (7.03–15.5 pg m−3). There

183

was a large range (3.0–126 pg m−3) for concentrations of Σ19Br-PAHs in the air

184

samples collected from around the metallurgical facilities investigated in this study

185

(Table 2). Spearman’s analysis was used to explore correlations between source

186

emissions and the concentrations in the surrounding areas. Spearman’s correlations 10


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between the stack gas and ambient air samples were calculated for the mean

188

concentrations of individual Cl-PAH and Br-PAH congeners and the mean

189

concentrations of all Cl-PAH and Br-PAH congeners, and showed relatively high

190

correlations (Table S2 and Figure S1). The total Br-PAHs showed a strong

191

correlation between the stack gas and ambient air samples with a 99% degree of

192

confidence in the Spearman’s correlation. The concentrations of individual Cl-PAHs

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were correlated to each other in stack gas and ambient air samples from all

194

metallurgical plants except the iron ore sinter plants. We speculated that other

195

industrial sources, such as waste incineration

196

of the iron ore sinter plants may affect the levels of Cl-PAHs and Br-PAHs in the

197

surrounding ambient air. Large fugitive emissions and low stack dispersion

198

capabilities for stack gases released from these sources may also be responsible for

199

the levels of Cl-PAHs and Br-PAHs in the surrounding ambient air.

200

18

and vehicle exhaust 12, in the vicinity

Emission factors and annual emission amounts of Cl/Br-PAHs from the

201

metallurgical plants

202

The emission factor is an important parameter for estimating the total emissions of

203

organic pollutants from industry. The emission factors of Cl-PAHs and Br-PAHs are

204

useful for preliminarily establishment of emission inventories for metal smelting on

205

national and/or global scales. In this study, the emission factors and total emission

206

amounts were calculated using Equations (2) and (3). The emission factors are

207

expressed in terms of mass and TEQ concentrations for stack gases released from the

208

investigated metallurgical plants (Table 3). 11



Emission factors by stack gas =

"#$#%&'%("#) *+')) "& ,-. × 01"2 &'%$ *2. '3'(%4 "0 +$%'1 )+$1%(#5

Total emission amount = emission factors × activity level of the reference year *3. 209

The mass-based emission factors for the iron ore sinter plants were higher (means: 1.3

210

mg t−1 for Cl-PAHs and 0.07 mg t−1 for Br-PAHs) than those for the secondary non-

211

ferrous smelters investigated in this study. Average emission factors of the Cl-PAHs

212

released into air were 0.6 mg t−1 for secondary aluminum smelters, 0.5 mg t−1 for

213

secondary lead smelters, and 0.3 mg t−1 for secondary copper smelters.30 For the Br-

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PAHs, the mean emission factors of the secondary aluminum smelters, secondary lead

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smelters, and secondary copper smelters were 0.04, 0.03, and 0.05 mg t−1,

216

respectively. The emission factors for the iron ore sintering plant (0.4 mg t−1 for Cl-

217

PAHs, 0.02 mg t−1 for Br-PAHs) and secondary aluminum smelter (0.2 mg t−1 for Cl-

218

PAHs, 0.04 mg t−1 for Br-PAHs) may be attributed to their complete stack gas

219

abatement systems and recycling equipment. These results suggest that the dust

220

removal and purification equipment used in these plants reduce the emissions of Cl-

221

PAHs and Br-PAHs.

222

TEQ emission factors were also calculated (Table 3). The mean emission factors

223

based on the TEQ concentrations were 2.6 µg TEQ t−1 for Cl-PAHs and 0.1 µg TEQ

224

t−1 for Br-PAHs from iron ore sintering, 1.3 µg TEQ t−1 for Cl-PAHs and 0.05 µg TEQ

225

t−1 for Br-PAHs from secondary aluminum smelting, and 0.4 µg TEQ t−1 for Cl-PAHs

226

and 0.01 µg TEQ t−1 for Br-PAHs from secondary lead smelting. The total releases of 12


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Cl-PAHs and Br-PAHs in the stack gases from the investigated metallurgical plants

228

were estimated according to the derived emission factors and the total annual

229

production of sintered ore (800 million tons),

230

tons), and secondary lead (1.6 million tons) in 2014 in China.

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total emissions of Cl-PAHs were approximately 1060 kg (2074 g TEQ) for iron ore

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sintering, 2.3 kg (4.85 g TEQ) for secondary aluminum smelting, and 0.8 kg (0.7 g

233

TEQ) for secondary lead smelting. Total emission amounts of Br-PAHs were

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approximately 55.2 kg (103.4 g TEQ) for iron ore sintering, 0.2 kg (0.2 g TEQ) for

235

secondary aluminum smelting, and 0.05 kg (0.02 g TEQ) for secondary lead smelting.

236

These are important basic data for establishing emission inventories for Cl-PAHs and

237

Br-PAHs from metallurgical industries.

238

31

secondary aluminum (3.7 million 32

The estimated annual

Congener profiles of Cl/Br-PAHs from the investigated metallurgical plants

239

For organic contaminants with many congeners, congener profiles can be used to

240

trace specific emission sources in the environment or biota. Congener profiles of Cl-

241

PAHs and Br-PAHs in stack gases released from the investigated metallurgical plants

242

were evaluated (Figure 1). For iron ore sintering, 9-chlorophenanthrene/2-

243

chlorophenanthrene (9-ClPhe/2-ClPhe, 25%–45%) were the dominant Cl-PAH

244

congeners in the stack gas, followed by 3-chlorophenanthrene (3-ClPhe, 13%–16%),

245

1-chloroanthracene (7%–14%), and 1-chloropyrene (~4%). For secondary aluminum

246

smelting, the congener profiles at the two investigated plants differed, and this may

247

have been caused by differences in the compositions of the raw materials. The raw

248

material used in plant Al1 was mainly aluminum scrap material (>95%) with smaller 13



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quantities of other non-ferrous scrap (< 4.5%), and the dominant congeners were 9-

250

ClPhe/2-ClPhe (45%), 3-ClPhe (16%), and 1-chloroanthracene (16%). By contrast,

251

the main raw material used in plant Al2 was electrolytic aluminum ingots with small

252

quantities of electrolytic copper, and the dominant Cl-PAH congener was 1-

253

chloropyrene

254

chlorobenzo[a]pyrene (14%). In the stack gases from the secondary lead smelters, 9-

255

ClPhe/2-ClPhe (60%) and 3-ClPhe (21%) were the dominant congeners. Generally,

256

the congener profiles of Cl-PAHs in the stack gas samples investigated in this study

257

were similar to those from secondary copper smelting facilities.30 However, they were

258

obviously different from the profiles for fly ash and bottom ash collected from the

259

waste incinerators,18 and floor dust in electronic waste recycling facilities,33 which

260

were dominated by 6-chlorobenzo[a]pyrene. For the Br-PAHs, 1-bromopyrene (1-

261

BrPyr) was the dominant congener in the stack gases from all the five metallurgical

262

plants investigated in this study. The congener profiles differed among the various

263

metallurgical plants. For iron ore sintering, the distribution of individual Br-PAHs was

264

relatively

265

bromophenanthrene,

266

bromoanthracene, 3-bromofluoranthene, and 7-bromobenz[a]anthracene all accounted

267

for approximately 10% of the total. For secondary aluminum smelting, 4-

268

bromopyrene was the dominant Br-PAH congener (24%), followed by 1-BrPyr (21%–

269

22%), and 3-bromofluoranthene (13%–16%). For secondary lead smelting, 1-BrPyr

270

was the most abundant Br-PAH congener (58%).

(37%),

balanced,

followed

and

by

congeners

9-ClPhe/2-ClPhe

such

9-bromophenanthrene,

as

1-BrPyr,

(22%),

and

4-bromopyrene,

2-bromophenanthrene,

14


6-

31-

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271

To evaluate the potential impact of stack gas emissions from the metallurgical plants

272

on the surroundings, the congener profiles of Cl-PAHs and Br-PAHs in ambient air

273

surrounding the investigated metallurgical plants were evaluated and compared with

274

the stack gas emission profiles (Figure 2). The congener profiles of Cl-PAHs and Br-

275

PAHs in the ambient air samples were similar to those in the stack gas emissions for

276

most of the investigated metallurgical plants. These results indicate that these

277

metallurgical sources contribute to the occurrence of Cl-PAHs and Br-PAHs in the

278

surrounding atmosphere.

279

The ratios of the concentrations of certain specific congeners of Cl-PAHs and Br-

280

PAHs can provide important information on source apportioning of Cl-PAHs and Br-

281

PAHs. We calculated concentration ratios for selected Cl-PAH congeners normalized

282

to 1-Cl-Pyr and 3-Cl-Flu, and selected Br-PAH congeners normalized to 1-Br-Pyr and

283

3-Br-Flu for stack gas samples collected from the metallurgical plants. The ratios of

284

specific congeners estimated for iron ore sintering and secondary non-ferrous

285

smelting (aluminum, lead, and copper), electronic shredder waste, floor dust from an

286

e-waste recycling facility, road tunnel air, fly ash, and stack gases from waste

287

incinerators were determined (Table S3). The 1-Cl-Pyr/3-Cl-Flu ratios for stack gases

288

from the three metallurgical plants investigated in this study were higher than those

289

from the other sources, except for the electronic shedder waste from the e-waste

290

recycling facility. Therefore, this ratio could be used to trace the sources of Cl-PAHs

291

in the environment. Principal component analysis of the ratios of the concentrations of

292

selected Cl-PAH congeners for the metal smelters and other sources was conducted 15



293

(Figure 3). The results for the metallurgical plants differed from those for the other

294

sources, except for road tunnel air and stack gas from waste incineration. Differences

295

between the ratios for the gas phase (stack gases from metallurgical processes and

296

waste incinerators, and road tunnel air) and solid phase (floor dust, fly ash, and e-

297

waste) could be attributed to the different distributions of Cl-PAHs between the two

298

phases, and significant differences between the gas/particle partitioning coefficients

299

for Cl-PAH congeners (−3.22 to −0.93). 2, 15 The fractions of Cl-PAHs in the gas phase

300

are reportedly higher than those in the particulate phase.34 These results show that iron

301

ore sintering and secondary non-ferrous smelting are important sources of Cl-PAHs

302

and Br-PAHs, and the congener profiles reported in this study can be used as

303

fingerprints for source traceability of Cl-PAHs and Br-PAHs in the environment.

304

Pearson correlation coefficients between Cl-PAH and Br-PAH congeners and their

305

parent PAH congeners were calculated to evaluate possible mechanisms of Cl-PAH

306

and Br-PAH formation (Table S4). We assumed that halogenation of PAHs was the

307

major pathway for formation of halogenated PAHs if the correlation between an

308

individual halogenated PAH and its corresponding parent PAH was significant. The

309

results showed there were several Cl-PAH congeners with significant correlations

310

with their parents PAHs, and direct chlorination of PAHs might not be a major

311

pathway for Cl-PAH formation for most congeners during iron ore sintering and

312

secondary non-ferrous metal smelting. This was in agreement with the results for the

313

secondary copper smelting process.30 Significant correlations were not found between

314

individual Br-PAHs and their corresponding parent PAHs, indicating that bromination 16


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315

of parent PAHs is not an important mechanism for Br-PAH formation. Furthermore,

316

obvious differences in the Pearson correlation coefficients between individual Br-

317

PAHs and their corresponding parent PAHs were found between the iron ore sintering

318

and secondary non-ferrous metal smelting processes in this study. Therefore, the

319

formation mechanisms for the organic brominated contaminants may be different in

320

iron ore sintering and secondary non-ferrous smelting processes.

321

The importance of Cl/Br-PAHs relative to other notorious unintentional

322

POPs

323

Contaminants, especially POPs, in the gas phase or particulate phase of ambient air

324

are of great concern because they are closely associated with mortality and

325

morbidity.35-37 Among the POPs, Cl-PAHs and Br-PAHs, which can induce AhR

326

activity and are carcinogenic and mutagenic, have been observed in urban and rural

327

air in recent studies.

328

released from electronic waste and secondary copper smelting facilities have adverse

329

effects on ambient air.

330

PAHs in ambient air surrounding the investigated metallurgical plants were

331

determined (Table S5). We estimated daily inhalation of Cl-PAHs and Br-PAHs based

332

on the TEQ concentrations in ambient air surrounding the investigated metallurgical

333

plants (Table S5, Equation S1). These inhalation calculations provide a preliminary

334

indication of the potential exposure risk associated with stack gas emissions from the

335

investigated plants. The mean TEQ concentrations of Cl-PAHs and Br-PAHs in the

336

ambient air surrounding the metal smelters were in the order iron ore sinter plants ≈

1, 7, 34

Previous studies have reported that Cl-PAHs and Br-PAHs

30, 38

In this study, the TEQ concentrations of Cl-PAHs and Br-

17



337

secondary aluminum smelters > secondary lead smelter. This order was almost

338

consistent with that in the stack gases, which indicates that stack gases are the main

339

source of these pollutants in the surrounding atmosphere. Therefore, reducing the

340

levels of Cl-PAHs and Br-PAHs in stack gas emissions will effectively reduce their

341

environmental risks. However, more intensive exposure assessments should be

342

conducted in the future.

343

PCDD/Fs are well-known unintentional POPs released from metallurgical sources.

344

Besides PCDD/Fs, many other unintentional POPs can be formed and released from

345

metallurgical sources.23,

346

unintentional POPs to identify priority contaminants released from important

347

industries. Induction of AhR activity is a common characteristic of these unintentional

348

POPs. Thus, to assess the importance of Cl-PAHs and Br-PAHs compared with other

349

unintentional POPs, we compared Cl/Br-PAHs with other unintentional POPs based

350

on the TEQ concentrations.

351

First, TEQ concentrations of Cl-PAHs and Br-PAHs emitted from the investigated

352

metallurgical plants via stack gas were estimated (Table S6), and then compared with

353

those of PCDD/Fs, PCNs, and PCBs. Average TEQ concentrations of the Cl-PAHs

354

released from iron ore sintering, secondary aluminum smelting, and secondary lead

355

smelting were 192, 194, and 121 pg TEQ Nm−3, respectively. Mean TEQ

356

concentrations of Br-PAHs were 9.24, 11.4, and 3.10 pg TEQ Nm−3, respectively. The

357

TEQ concentrations of Cl-PAHs released from the metallurgical facilities were

358

comparable to those of PCDD/Fs (2.88–385 pg WHO-TEQ Nm−3 for iron ore

24, 29, 30, 39

It is important to compare the levels of these

18


Page 18 of 31

Page 19 of 31


359

sintering, 0.05–0.72 ng TEQ Nm−3 for secondary aluminum smelting, and 0.05–0.73

360

ng TEQ Nm−3 for secondary lead smelting) in previous studies.

361

the TEQ concentrations of Cl-PAHs emitted from the three kinds of metallurgical

362

facilities investigated in this study were obviously higher than those of PCNs (2.83–

363

14.9 pg TEQ Nm−3 for iron ore sintering, 0.007–69.8 pg TEQ Nm−3 for secondary

364

aluminum smelting, and 10 pg TEQ Nm−3 for secondary lead smelting)

365

PCBs (0.05–14.9 pg TEQ Nm−3 for iron ore sintering, 0.1–200 pg TEQ Nm−3 for

366

secondary aluminum smelting, and 0.9–5 pg TEQ Nm−3 for secondary lead

367

smelting).23, 24, 29, 39, 43-47

368

In addition, the TEQ concentrations of Cl/Br-PAHs in the ambient air surrounding the

369

investigated metallurgical plants were also assessed and compared with those of

370

dioxins and dioxin-like (dl) compounds. For iron ore sinter plants, the mean TEQ

371

concentration of Cl-PAHs (1.78 pg TEQ m−3) was higher than those of PCDD/Fs (824

372

fg WHO-TEQ m−3), dl-PCBs (40.9 fg TEQ m−3), and dl-PCNs (1.05 fg TEQ m−3).

373

The mean TEQ concentration of Br-PAHs (0.11 pg TEQ m−3) was lower than that of

374

PCDD/Fs, but higher than those of dl-PCBs and dl-PCNs. For secondary aluminum

375

smelting, the mean TEQ concentrations of Cl-PAHs (0.68 pg TEQ m−3) and Br-PAHs

376

(0.13 pg TEQ m−3) in ambient air were obviously higher than those of PCDD/Fs (131

377

fg WHO-TEQ m−3), dl-PCBs (14.7 fg TEQ m−3), and dl-PCNs (0.4 fg TEQ m−3 )

378

reported in a previous study.29 For secondary lead smelting, the mean TEQ

379

concentrations of Cl-PAHs (0.04 pg TEQ m−3) and Br-PAHs (0.001 pg TEQ m−3)

380

were slightly lower than those of PCDD/Fs (45.6 fg WHO-TEQ m−3) and dl-PCBs (9 19


23, 24, 40, 41

Moreover,

39, 41, 42

and


381

fg TEQ m−3), but higher than that of dl-PCNs (0.1 fg TEQ m−3). Thus, metallurgical

382

industries are important sources of atmospheric emissions of the emerging organic

383

contaminants Cl-PAHs and Br-PAHs, and these sources should not be neglected. It is

384

important to note that halogenated PAHs are noticeable among the toxic chemicals

385

emitted from metallurgical processes. Moreover, halogenated PAHs should be

386

included in the list of dioxin like compounds when evaluating toxic contributions or

387

inhalation risks in ambient air.

388

389

Supporting Information Available

390

Equation S1, Tables S1–S6, and Figures S1–S2. This information is available free of

391

charge via the internet at http://pubs.acs.org/.

392

393

ACKNOWLEDGMENTS

394

This work was supported by the Chinese National 973 Program (Grant No.

395

2015CB453100), National Natural Science Foundation of China (Grant Nos.

396

91543108, 21777172), Beijing Natural Science Foundation (Grant No. 8182052), the

397

Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.

398

XDB14020102), and the Youth Innovation Promotion Association of the Chinese

399

Academy of Sciences (Grant No. 2016038) and Collaborative Project supported by

400

Chinese Academy of Sciences and Hebei Academy of Sciences.

401 20


Page 20 of 31

Page 21 of 31


402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444

REFERENCES (1).

Ohura, T.; Morita, M.; Makino, M.; Amagai, T.; Shimoi, K., Aryl hydrocarbon receptor-

mediated effects of chlorinated polycyclic aromatic hydrocarbons. Chem. Res. Toxicol. 2007, 20 (9), 1237-1241. (2).

Sun, J.-L.; Zeng, H.; Ni, H.-G., Halogenated polycyclic aromatic hydrocarbons in the

environment. Chemosphere 2013, 90 (6), 1751-1759. (3).

Horii, Y.; Khim, J. S.; Higley, E. B.; Giesy, J. P.; Ohura, T.; Kannan, K., Relative Potencies of

Individual Chlorinated and Brominated Polycyclic Aromatic Hydrocarbons for Induction of Aryl Hydrocarbon Receptor-Mediated Responses. Environ. Sci. Technol. 2009, 43 (6), 2159-2165. (4).

Ohura T, S. K., Amagai T, Shinomiya M, Discovery of Novel Halogenated Polycyclic

Aromatic Hydrocarbons in Urban Particulate Matters Occurrence, Photostability, and AhR Activity. Environ. Sci. Technol. 2009, 43 (7), 2269-2275. (5).

Wang, X.; Kang, H.; Wu, J., Determination of chlorinated polycyclic aromatic hydrocarbons

in water by solid-phase extraction coupled with gas chromatography and mass spectrometry. J. Sep. Sci. 2016, 39 (9), 1742-1748. (6).

Pinto, M.; Rebola, M.; Louro, H.; Antunes, A. M. M.; Josã©, S. S.; Rocha, M.; Silva, M. J. O.;

Cardoso, A. S., Chlorinated Polycyclic Aromatic Hydrocarbons Associated with Drinking Water Disinfection: Synthesis, Formation under Aqueous Chlorination Conditions and Genotoxic Effects. Polycyc. Aromat. Compd. 2014, 34 (4), 356-371. (7).

Ma, J.; Chen, Z.; Wu, M.; Feng, J.; Horii, Y.; Ohura, T.; Kannan, K., Airborne PM2.5/PM10-

Associated Chlorinated Polycyclic Aromatic Hydrocarbons and their Parent Compounds in a Suburban Area in Shanghai, China. Environ. Sci. Technol. 2013, 47 (14), 7615-7623. (8).

Ni, H. G.; Zeng, E. Y., Environmental and human exposure to soil chlorinated and brominated

polycyclic aromatic hydrocarbons in an urbanized region. Environ. Toxicol. Chem. 2012, 31 (7), 1494500. (9).

Ishaq, R.; Näf, C.; Zebühr, Y.; Broman, D.; Järnberg, U., PCBs, PCNs, PCDD/Fs, PAHs and

Cl-PAHs in air and water particulate samples––patterns and variations. Chemosphere 2003, 50 (9), 1131-1150. (10).

Nilsson, U. L.; Oestman, C. E., Chlorinated polycyclic aromatic hydrocarbons: method of

analysis and their occurrence in urban air. Environ. Sci. Technol. 1993, 27 (9), 1826-1831. (11).

Shiraishi, H.; Pilkington, N. H.; Otsuki, A.; Fuwa, K., Occurrence of chlorinated polynuclear

aromatic hydrocarbons in tap water. Environ Sci Technol 1985, 19 (7), 585-90. (12).

Haglund, P.; Alsberg, T.; Bergman, A.; Jansson, B., Analysis of halogenated polycyclic

aromatic hydrocarbons in urban air, snow and automobile exhaust. Chemosphere 1987, 16 (10), 24412450. (13).

Ohura, T.; Kitazawa, A.; Amagai, T.; Makino, M., Occurrence, profiles, and photostabilities of

chlorinated polycyclic aromatic hydrocarbons associated with particulates in urban air. Environ. Sci. Technol. 2005, 39 (1), 85-91. (14).

Ohura, T., Environmental behavior, sources, and effects of chlorinated polycyclic aromatic

hydrocarbons. The Scientific World J., 2007, 7, 372-380. (15).

Ohura, T.; Fujima, S.; Amagai, T.; Shinomiya, M., Chlorinated polycyclic aromatic

hydrocarbons in the atmosphere: seasonal levels, gas-particle partitioning, and origin. Environ. Sci. 21



445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488

Page 22 of 31

Technol. 2008, 42 (9), 3296-3302. (16).

Sun, J.-L.; Ni, H.-G.; Zeng, H., Occurrence of chlorinated and brominated polycyclic aromatic

hydrocarbons in surface sediments in Shenzhen, South China and its relationship to urbanization. J. Environ. Monit. 2011, 13 (10), 2775-2781. (17).

Kitazawa, A.; Amagai, T.; Ohura, T., Temporal trends and relationships of particulate

chlorinated polycyclic aromatic hydrocarbons and their parent compounds in urban air. Environ. Sci. Technol. 2006, 40 (15), 4592-4598. (18).

Horii, Y.; Ok, G.; Ohura, T.; Kannan, K., Occurrence and profiles of chlorinated and

brominated polycyclic aromatic hydrocarbons in waste incinerators. Environ. Sci. Technol. 2008, 42 (6), 1904-1909. (19).

Hidekichi, Y.; Kohei, U., Formation of chlorinated PAHs in exhaust gas from municipal waste

incinerators, and their mutagenic activities. Toxicol. Environ. Chem. 1997, 63 (1-4), 233-233. (20).

Jin, R.; Liu, G. R.; Zheng, M. H.; Jiang, X. X.; Zhao, Y. Y.; Yang, L. L.; Wu, X. L.; Xu, Y.,

Secondary Copper Smelters as Sources of Chlorinated and Brominated Polycyclic Aromatic Hydrocarbons. Environ. Sci. Technol. 2017, 51 (14), 7945-7953. (21).

Zhang, W.; Feng, C.; Wei, C.; Yan, B.; Wu, C.; Li, N., Identification and characterization of

polycyclic aromatic hydrocarbons in coking wastewater sludge. J. Sep. Sci. 2012, 35 (23), 3340-3346. (22).

Roland, W.; Fukuya, I.; Takashi, I.; Masao, T.; Takeshi, S.; Masaki, S., Formation of PCDF,

PCDD, PCB, and PCN in de novo synthesis from PAH: Mechanistic aspects and correlation to fluidized bed incinerators. Chemosphere 2001, 44 (6), 1429-1438. (23).

Ba, T.; Zheng, M.; Zhang, B.; Liu, W.; Su, G.; Xiao, K., Estimation and characterization of

PCDD/Fs and dioxin-like PCB emission from secondary zinc and lead metallurgies in China. J. Environ. Monit. 2009, 11 (4), 867-872. (24).

Ba, T.; Zheng, M.; Zhang, B.; Liu, W.; Xiao, K.; Zhang, L., Estimation and characterization of

PCDD/Fs and dioxin-like PCBs from secondary copper and aluminum metallurgies in China. Chemosphere 2009, 75 (9), 1173-1178. (25).

Liu, X.; Ye, M.; Wang, X.; Liu, W.; Zhu, T., Gas-phase and particle-phase PCDD/F congener

distributions in the flue gas from an iron ore sintering plant. Acta Scien. Circum. 2017, 4, 239-245. (26).

Falandysz, J., Polychlorinated naphthalenes: an environmental update. Environ. Pollut. 1998,

101 (1), 77-90. (27).

Falandysz, J.; Strandberg, L.; Bergqvist, P. A.; Kulp, S. E.; Strandberg, B.; Rappe, C.,

Polychlorinated Naphthalenes in Sediment and Biota from the Gdañsk Basin, Baltic Sea. Environ. Sci. Technol. 1996, 30 (11), 3266-3274. (28).

Wu, X.; Zheng, M.; Zhao, Y.; Yang, H.; Yang, L.; Jin, R.; Xu, Y.; Xiao, K.; Liu, W.; Liu, G.,

Thermochemical formation of polychlorinated dibenzo-p-dioxins and dibenzofurans on the fly ash matrix from metal smelting sources. Chemosphere 2018, 191, 825-831. (29).

Yang, L.; Liu, G.; Zheng, M.; Jin, R.; Zhu, Q.; Zhao, Y.; Zhang, X.; Xu, Y., Atmospheric

occurrence and health risks of PCDD/Fs, polychlorinated biphenyls, and polychlorinated naphthalenes by air inhalation in metallurgical plants. Sci. Total Environ. 2017, 580, 1146-1154. (30).

Jin, R.; Liu, G.; Zheng, M.; Jiang, X.; Zhao, Y.; Yang, L.; Wu, X.; Xu, Y., Secondary Copper

Smelters as Sources of Chlorinated and Brominated Polycyclic Aromatic Hydrocarbons. Environ. Sci. Technol. 2017, 51 (14), 7945-7953. (31).

Sha, Y., Perspective and Challenges of Ironmaking in China. Anang Technology 2015, 2, 1-8.

(32).

USGS,

2014

Minerals

Yearbook-China 22


[advance

Release].

Page 23 of 31


489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532

https://minerals.usgs.gov/minerals/pubs/country/2014/myb3-2014-ch.pdf 2017. (33).

Ma, J.; Horii, Y.; Cheng, J.; Wang, W.; Wu, Q.; Ohura, T.; Kannan, K., Chlorinated and Parent

Polycyclic Aromatic Hydrocarbons in Environmental Samples from an Electronic Waste Recycling Facility and a Chemical Industrial Complex in China. Environ. Sci. Technol. 2009, 43 (3), 643-649. (34).

Jin, R.; Liu, G. R.; Jiang, X. X.; Liang, Y.; Fiedler, H.; Yang, L. L.; Zhu, Q. Q.; Xu, Y.; Gao, L.

R.; Su, G. J.; Xiao, K.; Zheng, M. H., Profiles, sources and potential exposures of parent, chlorinated and brominated polycyclic aromatic hydrocarbons in haze associated atmosphere. Sci. Total Environ. 2017, 593, 390-398. (35).

Pope, C. A.; Burnett, R. T.; Thun, M. J.; Calle, E. E.; Krewski, D.; Ito, K.; Thurston, G. D.,

Lung cancer, cardiopulmonary mortality, and long-term exposure to fine particulate air pollution. JAMA 2002, 287 (9), 1132-1141. (36).

Van den Berg, M.; Birnbaum, L. S.; Denison, M.; De Vito, M.; Farland, W.; Feeley, M.;

Fiedler, H.; Hakansson, H.; Hanberg, A.; Haws, L.; Rose, M.; Safe, S.; Schrenk, D.; Tohyama, C.; Tritscher, A.; Tuomisto, J.; Tysklind, M.; Walker, N.; Peterson, R. E., The 2005 World Health Organization reevaluation of human and Mammalian toxic equivalency factors for dioxins and dioxinlike compounds. Toxicol Sci 2006, 93 (2), 223-241. (37).

Beelen, R.; Hoek, G.; van den Brandt, P. A.; Goldbohm, R. A.; Fischer, P.; Schouten, L. J.;

Jerrett, M.; Hughes, E.; Armstrong, B.; Brunekreef, B., Long-term effects of traffic-related air pollution on mortality in a Dutch cohort (NLCS-AIR study). Environ Health Perspect 2008, 116 (2), 196-202. (38).

Wang, J.; Chen, S.; Tian, M.; Zheng, X.; Gonzales, L.; Ohura, T.; Mai, B.; Simonich, S. L. M.,

Inhalation Cancer Risk Associated with Exposure to Complex Polycyclic Aromatic Hydrocarbon Mixtures in an Electronic Waste and Urban Area in South China. Environ. Sci. Technol. 2012, 46 (17), 9745-9752. (39).

Ba, T.; Zheng, M.; Zhang, B.; Liu, W.; Su, G.; Liu, G.; Xiao, K., Estimation and Congener-

Specific Characterization of Polychlorinated Naphthalene Emissions from Secondary Nonferrous Metallurgical Facilities in China. Environ. Sci. Technol. 2010, 44 (7), 2441-2446. (40).

Wang, Y. H.; Lin, C.; Lai, Y. C.; Chang-Chien, G. P., Characterization of PCDD/Fs, PAHs, and

heavy metals in a secondary aluminum smelter. J Environ Sci Health A Tox Hazard Subst Environ Eng 2009, 44 (13), 1335-1342. (41).

Li, S.; Liu, G.; Zheng, M.; Liu, W.; Li, J.; Wang, M.; Li, C.; Chen, Y., Unintentional

production of persistent chlorinated and brominated organic pollutants during iron ore sintering processes. J. Hazard. Mater. 2017, 331, 63-70. (42).

Jiang, X.; Liu, G.; Wang, M.; Liu, W.; Tang, C.; Li, L.; Zheng, M., Case study of

polychlorinated naphthalene emissions and factors influencing emission variations in secondary aluminum production. J. Hazard. Mater. 2015, 286, 545-552. (43).

Niu, J.; Wang, L.; Yang, Z., QSPRs on photodegradation half-lives of atmospheric chlorinated

polycyclic aromatic hydrocarbons associated with particulates. Ecotoxicol. Environ. Saf. 2007, 66 (2), 272-277. (44).

Zou, C.; Han, J.; Zhang, M.; Zhang, S.; Qing, X.; Fu, H., Concentration and characterization

of PCDD/Fs emission from secondary lead and aluminum metallurgy plants. China Environ. Sci. 2012, 32 (7), 1309-1313. (45).

Kevin, J.; Eric, A.; Raymond, F.; R, A. D.; Adrian, P., Assessment of Exposure to PCDD/F,

PCB, and PAH at a Basic Oxygen Steelmaking (BOS) and an Iron Ore Sintering Plant in the UK. Ann. Occup. Hyg. 2012, 56 (1), 37-48. 23



533 534 535 536 537 538 539 540 541

(46).

Hu, J.; Zheng, M.; Liu, W.; Li, C.; Nie, Z.; Liu, G.; Xiao, K.; Dong, S., Occupational

Exposure to Polychlorinated Dibenzo-p-dioxins and Dibenzofurans, Dioxin-like Polychlorinated Biphenyls, and Polychlorinated Naphthalenes in Workplaces of Secondary Nonferrous Metallurgical Facilities in China. Environ. Sci. Technol. 2013, 47 (14), 7773-7779. (47).

Aries, E.; Anderson, D. R.; Fisher, R.; Fray, T. A. T.; Hemfrey, D., PCDD/F and “Dioxin-like”

PCB emissions from iron ore sintering plants in the UK. Chemosphere 2006, 65 (9), 1470-1480. (48).

Ohura, T.; Kitazawa, A.; Amagai, T.; Shinomiya, M., Relation-ships between chlorinated

polycyclic aromatic hydrocarbons and dioxins in urban air and incinerators. Organohalogen Compd. 2007, 69, 2902-2905.

542

24


Page 24 of 31

Page 25 of 31


Table Legends Table 1. Basic information for the metallurgical plants investigated in this study. Table 2. Average concentrations of ΣCl-PAHs and ΣBr-PAHs in the stack gas and ambient air samples from in and around several metallurgical plants. Table 3. Mass emission factors and TEQ emission factors of ΣCl-PAHs and ΣBrPAHs for samples from the metallurgical plants.

Figure Legends Figure 1. Fractions of individual (A) Cl-PAHs and (B) Br-PAHs in stack gas samples from iron ore sinter plants (Fe1, Fe2), secondary aluminum smelters (Al1, Al2) and secondary lead smelters (Pb). Figure 2. Fractions of individual (A) Cl-PAHs and (B) Br-PAHs in stack gas and ambient air samples from iron ore sinter plants (Fe1, Fe2), secondary aluminum smelters (Al1, Al2) and secondary lead smelters (Pb). Figure 3. PCA analysis of the Cl-PAH congener ratios from sources in this study and previous studies. Abbreviations and references: floor dust, floor dust from e-waste recycling facilities;33 e-waste, electronic shredder waste; 33 w-fly-ash and w-stack-gas, fly ash and stack gas from a waste incinerator; 18, 48 and road tunnel air. 12

25



Page 26 of 31

Table 1. Abbreviation of investigated plants Fe1

Category of metallurgical plants

furnace

Raw materials

Fuel reductant

iron ore sintering

iron ore fine, bentonite, pulverized coal

coal

bag filters

Fe2

iron ore sintering

blended ores, dolomite, limestone, quicklime

secondary aluminum smelting

coal oven gas (COG), anthracite and coke Natural gas

electrostatic precipitation and bag filters

Al1

sintering machine (sintering bed: 265 m2) sintering machine (sintering bed: 265 m2) rotary furnace

Al2

secondary aluminum smelting

rotary furnace

Natural gas

Pb

secondary lead smelting

shaft furnace

Water membrane duster and bag filters bag filters

aluminum scrap (>95%), magnesium, copper and other nonferrous scrap electrolytic aluminum ingots, electrolytic copper and copper scrap (

Chlorinated and Brominated Polycyclic Aromatic Hydrocarbons from

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