Chemosphere 119 (2015) 1208–1216
Contents lists available at ScienceDirect
Chemosphere journal homepage: www.elsevier.com/locate/chemosphere
Quantities, sources and adsorption of polybrominated diphenyl ethers in components of surficial sediments collected in Songhua River (Jilin City), China Ting Wang a,b, Shanshan Li c, Chen Zhang a, Yu Li a,⇑ a b c
Resources and Environmental Research Academy, North China Electric Power University, Beijing 102206, China State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environment Sciences, Beijing 100012, China Department of Civil and Environmental Engineering, University of Louisville, Louisville KY 40292, United States
h i g h l i g h t s The pollution of upstream sediments in Songhua River was dominated by
R8PBDEs.
Main source of PBDE in the sediments were from Deca-BDE commercial formulations. The synergism of Mn oxides and other components was found during PBDEs’ adsorption. The mechanism of Mn oxides inhibiting PBDEs’ adsorption was oxidation.
a r t i c l e
i n f o
Article history: Received 23 March 2014 Received in revised form 28 September 2014 Accepted 5 October 2014 Available online 1 November 2014 Handling Editor: Klaus Kümmerer Keywords: Polybrominated diphenyl ethers Surficial sediments Adsorption Factor analysis Multiple linear regressions
a b s t r a c t Quantities of polybrominated diphenyl ethers (PBDEs, BDE-28, 47, 99, 100, 153, 154, 183 and 209) in surficial sediments (SSs) of the Songhua River, China were extracted and detected by Soxhlet extractor and gas chromatography/mass spectrometry (GC/MS). Sources of the PBDEs were investigated by factor analysis. Contributions of Fe oxides, Mn oxides and organic matters (OMs), and their interactions of SSs to the adsorption of PBDEs were described based on multiple linear regressions. The analysis results from GC/ MS indicated that the concentrations of PBDEs ranged from 2.90 to 9871 ng g1 (dry weight) with a mean value of 397 ng g1. The congener profiles of the SSs were dominated by BDE-209 (P71.8%). Relatively high contents of PBDEs were observed in SSs from the upstream section. Deca-BDE commercial formulations constituted the largest contribution (33.6%) to PBDEs in the SSs, followed by Penta-BDE commercial formulations (21.7%) and Octa-BDE commercial formulations (13.2%). Each of the components in the SSs contributes positively to PBDEs’ adsorption. Synergism of Fe oxides and OMs was observed in the PBDEs’ adsorption. The interactions of Mn oxides and other components inhibited the PBDEs’ adsorption onto SSs, and the antagonism in the BDE-209 adsorption was stronger than other R7PBDEs (BDE-28, 47, 99, 100, 153, 154 and 183). However, the synergism observed in the R7PBDEs adsorption was stronger than BDE-209. The BDE-209 in SSs mainly came from Deca-BDE commercial formulations. The adsorption of PBDEs onto SSs was affected by the octanol–water coefficient (Kow) of the PBDEs’ congeners and the components of the SSs. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction PBDEs were used in large quantities as additive flame-retardants in commercial and household products (plastics, building materials, electrical appliances and textiles). The rapid increase in the usage of PBDEs in the last two decades has raised the level of PBDEs in the environment worldwide (Wit, 2002; Zhao et al., ⇑ Corresponding author. Tel./Fax: +86 10 61773886. E-mail address: [email protected] (Y. Li). http://dx.doi.org/10.1016/j.chemosphere.2014.10.015 0045-6535/Ó 2014 Elsevier Ltd. All rights reserved.
2010; Nouira et al., 2013; Lim et al., 2014; Mahmood et al., 2015). PBDEs and their metabolites were structurally similar to polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) (Hooper and McDonald, 2000). PBDEs have been associated with thyroid hormone disruption, neurobehavioral toxicity and cancer, based on available toxicity data and their structural and mechanistic similarities to PCBs (McDonald, 2002). Currently, PBDEs were ubiquitous environmental contaminants that have been generating social concern due to their persistence in the environment, tendency for bioaccumulation and potential
T. Wang et al. / Chemosphere 119 (2015) 1208–1216
toxicity to the ecosystem and humans (Law et al., 2006, 2008). In 2009 the Parties of the Stockholm Convention took the decision to list commercial Penta-BDE and commercial Octa-BDE as for Persistent Organic Pollutants (POPs) (UNEP, 2009). China restricted Penta-BDEs production in 2007. The Europe Union (EU) restricted using of PBDEs in 2008. The United States restricted PBDEs production, import and sale in the country at the end of 2013 (EPA, 2010). However, Deca-BDE is still used in many countries. PBDEs dissolved in rivers can be transferred into air and solid particles (sediments and suspended particles) via diffusion and partition, and can be transformed to other organic pollutants through degradation. Several transfer processes are used to describe the fate of PBDEs in the environment of the river, including air–water exchange, dry and wet deposition, riverine runoff, adsorption– desorption, uptake and degradation (Langford et al., 2005; Guan et al., 2009; Sepúlveda et al., 2010). Therefore, in order to clearly understand the transfer process of PBDEs in river, further researches about adsorption of PBDEs will be required (Guan et al., 2009). Surficial sediments (SSs) were considered as both final sinks and potential sources of contaminants in aquatic environments. Fe oxides, Mn oxides and organic matter were proved to be the three most important sediment components influencing adsorption of organic contaminants (Li and Werth, 2001; Li et al., 2009; Wang et al., 2009). Until now, studies on the roles of sediments’ components mainly focused on organic materials because most studies indicated that organic materials were the predominant sorbents unless their content of organic carbon is below 0.1% by mass (Kile et al., 1995; Wang et al., 2005). The research of Gouin and Harner indicated that PBDEs will largely partition to organic carbon in soil and sediment because of their physical–chemical properties (Gouin and Harner, 2003). Data analysed by correlation showed that there were only moderate or low correlations between PBDE levels and total contents of organic carbon (TOC) in the SSs from the Yangtze River Delta (Chen et al., 2006). The other components (such as Fe oxides and Mn oxides) in SSs may also indirectly contribute to the adsorption of organic contaminants, because interactions between various sediment components might occur (Li et al., 2009; Wang et al., 2009). For instance, both OMs and metal oxyhydroxides may coat the surface of silicate minerals, and change their affinity to organic pollutants (Laird et al., 1992). The adsorption of bisphenol A, pentachlorophenol, and nitrobenzene onto sediments indicated that Fe oxides played a positive role in the adsorption of the three organic contaminants onto SSs, and that Mn oxides inhibited the adsorption of the organic contaminants (Wang et al., 2008, 2009; Li et al., 2009). Research showed that changes in redox potential (Eh) accelerate sorption and desorption of organic contaminants (Eggleton and Thomas, 2004). Adsorption of OMs to hydrous Fe oxides was up to five times larger for oxic than anoxic solutions (Hankea et al., 2014). Mn oxides, as an important natural oxidant, formed through oxidation of Mn (II) on Fe oxides. The Mn oxides formed on Fe oxides take up the sorption sites previously occupied by metal (Ren et al., 2013). Studies on adsorption behaviours of PBDEs in components of SSs, including OMs, Fe oxides and Mn oxides, have been rarely reported. Principal component analysis (PCA) was a multivariate analytical tool used for receptor modelling in environmental source apportionment studies (Ye et al., 2005; Liu et al., 2008; Sofowote et al., 2008). By utilizing the orthogonal transformation method, principle components (PCs) were extracted with different factor loadings indicating correlations of each pollutant species (variables) with each PC. PCA have previously been widely used to identify sources of polycyclic aromatic hydrocarbons (PAHs), PCBs and polychlorinated dibenzo(p)dioxin and furan in sediments (Wang et al., 2010; Gao et al., 2013; White et al., 2014). The Songhua River in the northeast of China, with a total basin area of 55.68 104 km2 (920 km in length and 1070 km in width)
1209
and covering 44.9% of northeast China and 5.8% of the whole country, is the third largest river in China for its water volume. Jilin City, located in the upstream of the Songhua River, has been developed with a variety of industries in recent years. The growing industry has resulted in the pollution of the Songhua River in the section of Jilin City, as well as the downstream of this river section. Analysis of PCBs, organ chlorine pesticides (OCPs), other persistent organics and metals in the sediments indicated that the Songhua River was polluted (Wang et al., 2007; Lin et al., 2008; Wang et al., 2012). However, no study on PBDEs has been conducted in this region. The goal of this paper was to investigate the quantities, spatial distribution and sources of PBDEs in the sediments from the Songhua River in Jilin City. In addition, the distribution of PBDEs on Mn oxides, Fe oxides and OMs of the sediments were also assessed. 2. Materials and methods 2.1. Reagents All solvents used in this work were of analytical grade. The PBDE analytical standard (BDE-CM, including BDE-28, 47, 99, 100, 153, 154, 183, 209) was purchased from AccuStandard (New Haven, CT, USA). 2.2. Sample collection SSs samples (
Contents lists available at ScienceDirect
Chemosphere journal homepage: www.elsevier.com/locate/chemosphere
Quantities, sources and adsorption of polybrominated diphenyl ethers in components of surficial sediments collected in Songhua River (Jilin City), China Ting Wang a,b, Shanshan Li c, Chen Zhang a, Yu Li a,⇑ a b c
Resources and Environmental Research Academy, North China Electric Power University, Beijing 102206, China State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environment Sciences, Beijing 100012, China Department of Civil and Environmental Engineering, University of Louisville, Louisville KY 40292, United States
h i g h l i g h t s The pollution of upstream sediments in Songhua River was dominated by
R8PBDEs.
Main source of PBDE in the sediments were from Deca-BDE commercial formulations. The synergism of Mn oxides and other components was found during PBDEs’ adsorption. The mechanism of Mn oxides inhibiting PBDEs’ adsorption was oxidation.
a r t i c l e
i n f o
Article history: Received 23 March 2014 Received in revised form 28 September 2014 Accepted 5 October 2014 Available online 1 November 2014 Handling Editor: Klaus Kümmerer Keywords: Polybrominated diphenyl ethers Surficial sediments Adsorption Factor analysis Multiple linear regressions
a b s t r a c t Quantities of polybrominated diphenyl ethers (PBDEs, BDE-28, 47, 99, 100, 153, 154, 183 and 209) in surficial sediments (SSs) of the Songhua River, China were extracted and detected by Soxhlet extractor and gas chromatography/mass spectrometry (GC/MS). Sources of the PBDEs were investigated by factor analysis. Contributions of Fe oxides, Mn oxides and organic matters (OMs), and their interactions of SSs to the adsorption of PBDEs were described based on multiple linear regressions. The analysis results from GC/ MS indicated that the concentrations of PBDEs ranged from 2.90 to 9871 ng g1 (dry weight) with a mean value of 397 ng g1. The congener profiles of the SSs were dominated by BDE-209 (P71.8%). Relatively high contents of PBDEs were observed in SSs from the upstream section. Deca-BDE commercial formulations constituted the largest contribution (33.6%) to PBDEs in the SSs, followed by Penta-BDE commercial formulations (21.7%) and Octa-BDE commercial formulations (13.2%). Each of the components in the SSs contributes positively to PBDEs’ adsorption. Synergism of Fe oxides and OMs was observed in the PBDEs’ adsorption. The interactions of Mn oxides and other components inhibited the PBDEs’ adsorption onto SSs, and the antagonism in the BDE-209 adsorption was stronger than other R7PBDEs (BDE-28, 47, 99, 100, 153, 154 and 183). However, the synergism observed in the R7PBDEs adsorption was stronger than BDE-209. The BDE-209 in SSs mainly came from Deca-BDE commercial formulations. The adsorption of PBDEs onto SSs was affected by the octanol–water coefficient (Kow) of the PBDEs’ congeners and the components of the SSs. Ó 2014 Elsevier Ltd. All rights reserved.
1. Introduction PBDEs were used in large quantities as additive flame-retardants in commercial and household products (plastics, building materials, electrical appliances and textiles). The rapid increase in the usage of PBDEs in the last two decades has raised the level of PBDEs in the environment worldwide (Wit, 2002; Zhao et al., ⇑ Corresponding author. Tel./Fax: +86 10 61773886. E-mail address: [email protected] (Y. Li). http://dx.doi.org/10.1016/j.chemosphere.2014.10.015 0045-6535/Ó 2014 Elsevier Ltd. All rights reserved.
2010; Nouira et al., 2013; Lim et al., 2014; Mahmood et al., 2015). PBDEs and their metabolites were structurally similar to polychlorinated biphenyls (PCBs) and dichlorodiphenyltrichloroethane (DDT) (Hooper and McDonald, 2000). PBDEs have been associated with thyroid hormone disruption, neurobehavioral toxicity and cancer, based on available toxicity data and their structural and mechanistic similarities to PCBs (McDonald, 2002). Currently, PBDEs were ubiquitous environmental contaminants that have been generating social concern due to their persistence in the environment, tendency for bioaccumulation and potential
T. Wang et al. / Chemosphere 119 (2015) 1208–1216
toxicity to the ecosystem and humans (Law et al., 2006, 2008). In 2009 the Parties of the Stockholm Convention took the decision to list commercial Penta-BDE and commercial Octa-BDE as for Persistent Organic Pollutants (POPs) (UNEP, 2009). China restricted Penta-BDEs production in 2007. The Europe Union (EU) restricted using of PBDEs in 2008. The United States restricted PBDEs production, import and sale in the country at the end of 2013 (EPA, 2010). However, Deca-BDE is still used in many countries. PBDEs dissolved in rivers can be transferred into air and solid particles (sediments and suspended particles) via diffusion and partition, and can be transformed to other organic pollutants through degradation. Several transfer processes are used to describe the fate of PBDEs in the environment of the river, including air–water exchange, dry and wet deposition, riverine runoff, adsorption– desorption, uptake and degradation (Langford et al., 2005; Guan et al., 2009; Sepúlveda et al., 2010). Therefore, in order to clearly understand the transfer process of PBDEs in river, further researches about adsorption of PBDEs will be required (Guan et al., 2009). Surficial sediments (SSs) were considered as both final sinks and potential sources of contaminants in aquatic environments. Fe oxides, Mn oxides and organic matter were proved to be the three most important sediment components influencing adsorption of organic contaminants (Li and Werth, 2001; Li et al., 2009; Wang et al., 2009). Until now, studies on the roles of sediments’ components mainly focused on organic materials because most studies indicated that organic materials were the predominant sorbents unless their content of organic carbon is below 0.1% by mass (Kile et al., 1995; Wang et al., 2005). The research of Gouin and Harner indicated that PBDEs will largely partition to organic carbon in soil and sediment because of their physical–chemical properties (Gouin and Harner, 2003). Data analysed by correlation showed that there were only moderate or low correlations between PBDE levels and total contents of organic carbon (TOC) in the SSs from the Yangtze River Delta (Chen et al., 2006). The other components (such as Fe oxides and Mn oxides) in SSs may also indirectly contribute to the adsorption of organic contaminants, because interactions between various sediment components might occur (Li et al., 2009; Wang et al., 2009). For instance, both OMs and metal oxyhydroxides may coat the surface of silicate minerals, and change their affinity to organic pollutants (Laird et al., 1992). The adsorption of bisphenol A, pentachlorophenol, and nitrobenzene onto sediments indicated that Fe oxides played a positive role in the adsorption of the three organic contaminants onto SSs, and that Mn oxides inhibited the adsorption of the organic contaminants (Wang et al., 2008, 2009; Li et al., 2009). Research showed that changes in redox potential (Eh) accelerate sorption and desorption of organic contaminants (Eggleton and Thomas, 2004). Adsorption of OMs to hydrous Fe oxides was up to five times larger for oxic than anoxic solutions (Hankea et al., 2014). Mn oxides, as an important natural oxidant, formed through oxidation of Mn (II) on Fe oxides. The Mn oxides formed on Fe oxides take up the sorption sites previously occupied by metal (Ren et al., 2013). Studies on adsorption behaviours of PBDEs in components of SSs, including OMs, Fe oxides and Mn oxides, have been rarely reported. Principal component analysis (PCA) was a multivariate analytical tool used for receptor modelling in environmental source apportionment studies (Ye et al., 2005; Liu et al., 2008; Sofowote et al., 2008). By utilizing the orthogonal transformation method, principle components (PCs) were extracted with different factor loadings indicating correlations of each pollutant species (variables) with each PC. PCA have previously been widely used to identify sources of polycyclic aromatic hydrocarbons (PAHs), PCBs and polychlorinated dibenzo(p)dioxin and furan in sediments (Wang et al., 2010; Gao et al., 2013; White et al., 2014). The Songhua River in the northeast of China, with a total basin area of 55.68 104 km2 (920 km in length and 1070 km in width)
1209
and covering 44.9% of northeast China and 5.8% of the whole country, is the third largest river in China for its water volume. Jilin City, located in the upstream of the Songhua River, has been developed with a variety of industries in recent years. The growing industry has resulted in the pollution of the Songhua River in the section of Jilin City, as well as the downstream of this river section. Analysis of PCBs, organ chlorine pesticides (OCPs), other persistent organics and metals in the sediments indicated that the Songhua River was polluted (Wang et al., 2007; Lin et al., 2008; Wang et al., 2012). However, no study on PBDEs has been conducted in this region. The goal of this paper was to investigate the quantities, spatial distribution and sources of PBDEs in the sediments from the Songhua River in Jilin City. In addition, the distribution of PBDEs on Mn oxides, Fe oxides and OMs of the sediments were also assessed. 2. Materials and methods 2.1. Reagents All solvents used in this work were of analytical grade. The PBDE analytical standard (BDE-CM, including BDE-28, 47, 99, 100, 153, 154, 183, 209) was purchased from AccuStandard (New Haven, CT, USA). 2.2. Sample collection SSs samples (
