The contribution of waste water treatment plants to PBDEs in ambient air

Toxic Organic Contaminants in Airborne Particles: Levels, Potential Sources and Risk Assessment

In the last years, many studies have focused on risk assessment of exposure of workers to airborne particulate matter (PM). Several studies indicate a strong correlation between PM and adverse health outcomes, as a function of particle size. In the last years, the study of atmospheric particulate matter has focused more on particles less than 10 μm or 2.5 μm in diameter; however, recent studies identify in particles less than 0.1 μm the main responsibility for negative cardiovascular effects. The present paper deals with the determination of 66 organic compounds belonging to six different classes of persistent organic pollutants (POPs) in the ultrafine, fine and coarse fractions of PM (PM < 0.1 µm; 0.1 < PM < 2.5 µm and 2.5 < PM < 10 µm) collected in three outdoor workplaces and in an urban outdoor area. Data obtained were analyzed with principal component analysis (PCA), in order to underline possible correlation between sites and classes of pollutants and characteristic emission sources. Emission source studies are, in fact, a valuable tool for both identifying the type of emission source and estimating the strength of each contamination source, as useful indicator of environment healthiness. Moreover, both carcinogenic and non-carcinogenic risks were determined in order to estimate human health risk associated to study sites. Risk analysis was carried out evaluating the contribution of pollutant distribution in PM size fractions for all the sites. The results highlighted significant differences between the sites and specific sources of pollutants related to work activities were identified. In all the sites and for all the size fractions of PM both carcinogenic and non-carcinogenic risk values were below acceptable and safe levels of risks recommended by the regulatory agencies.

Insights into the Occurrence, Fate, and Impacts of Halogenated Flame Retardants in Municipal Wastewater Treatment Plants

Halogenated flame retardants (HFRs) have been extensively used in various consumer products and many are classified as persistent organic pollutants due to their resistance to degradation, bioaccumulation potential and toxicity. HFRs have been widely detected in the municipal wastewater and wastewater treatment solids in wastewater treatment plants (WWTPs), the discharge and agricultural application of which represent a primary source of environmental HFRs contamination. This review seeks to provide a current overview on the occurrence, fate, and impacts of HFRs in WWTPs around the globe. We first summarize studies recording the occurrence of representative HFRs in wastewater and wastewater treatment solids, revealing temporal and geographical trends in HFRs distribution. Then, the efficiency and mechanism of HFRs removal by biosorption, which is known to be the primary process for HFRs removal from wastewater, during biological wastewater treatment processes, are discussed. Transformation of HFRs via abiotic and biotic processes in laboratory tests and full-scale WWTPs is reviewed with particular emphasis on the transformation pathways and functional microorganisms responsible for HFRs biotransformation. Finally, the potential impacts of HFRs on reactor performance (i.e., nitrogen removal and methanogenesis) and microbiome in bioreactors are discussed. This review aims to advance our understanding of the fate and impacts of HFRs in WWTPs and shed light on important questions warranting further investigation.

Variability of release rate of flame retardants in wastewater treatment plants

Information on variability is important in the assessment of the releases and potential risks of brominated flame retardants (BRFs) in the environment, but related data are limited. In this study, two release-characterizing parameters, release fraction to final effluent and influent-biosolids transfer coefficient, were used to quantify releases of five BFRs from eight secondary wastewater treatment plants (WWTPs). The five BFRs are recalcitrant, hydrophobic, and low in volatility. The two parameters for these BFRs were found to vary from day to day and season to season within individual WWTPs as well as from one WWTP to another. These temporal and spatial variations were, however, comparable to each other and both within a factor of 3 above or below the parameter averages. Averages for release fraction were in the range of 0.02-0.29 and those for influent-biosolids transfer coefficient in the range of 3-26 L/g, depending upon a given BFR at a given WWTP. These ranges and the observed factor-3 variability are not only useful for estimating releases of the five BFRs, but more importantly provide read-across data for the assessment of substances with similar physical-chemical properties.

A review on the sustainability of textile industries wastewater with and without treatment methodologies

The textile industry in India plays a vital role in the economic growth of the nation. The growth of the textile industry not only impacts the economy of a country but also influences the global economy and mutual exchange of technology between the countries. However, the textile industry also generates an enormous quantity of waste as waste sludge, fibers and chemically polluted waters. The chemically polluted textile wastewater degrades the quality of the soil and water when it mixes with these natural resources and its dependent habitats and environment. Owing to the existing problem of solid and liquid waste, textile industries are facing major problems in environment pollution. Therefore, researchers and the textile industries are focusing on the reduction of textile wastewater and the formulation of alternative efficient treatment techniques without hampering the environment. Hence, the present literature survey mainly concentrates on the various wastewater treatment techniques and their advantages. Moreover, the focus of the study was to describe the methods for the reduction of environmental waste and effective utilization of recycled water with zero wastewater management techniques. The alternative methods for the reduction of textile waste are also covered in this investigation. Finally, this paper also suggests utilization of solid wastes after treatment of wastewater in other sectors like construction for the preparation of low-grade tiles and or bricks by replacing the cement normally used in their manufacturing.

Molecular structure and vibrational spectra of 2,2',4,4',6-pentabromodiphenyl ether (BDE 100)

In this work, FT-IR ATR and Raman (laser line 532nm) spectra of 2,2',4,4',6-pentabromodiphenyl ether (BDE 100) have been recorded in the range of 4000-650 and 4000-100cm^-1, respectively. A combined experimental and theoretical approach (DFT/B3LYP/6-311++g** and aug-cc-pVDZ) was used to study molecular structure of BDE 100. Optimization of geometry in the gas phase at these levels of theory indicated that the BDE 100 has skew conformation. The detailed assignment of IR and Raman bands of BDE 100 was done on the basis of calculated results for the most stable conformer. The scaled theoretical frequencies are in good agreement with the experimental ones. Both experimental and theoretical IR and Raman spectra of BDE 100, one of the members of the family of flame retardants, are presented here for the first time.

Evaluation of a QuEChERS-like extraction approach for the determination of PBDEs in mussels by immuno-assay-based screening methods

A sample preparation method was evaluated for the determination of polybrominated diphenyl ethers (PBDEs) in mussel samples, by using colorimetric and electrochemical immunoassay-based screening methods. Herein, a rapid procedure based on QuEChERS-like extraction approach followed by solid phase purification was optimized for PBDE extraction from mussel samples. The detection limits for colorimetric and electrochemical immunoassays, calculated as BDE-47 equivalent concentration, were 0.6ngg^-1 and 1.1ngg^-1, respectively. Real mussel samples, including a Certified Reference Material (CRM), were analyzed. The samples were measured by colorimetric and electrochemical immunoassays as well as by GC-MS. In comparison to GC-MS results, 106% and 102% relative accuracy were obtained for the colorimetric and electrochemical immunoassays, respectively. The proposed method could be useful for massive environmental campaigns, being able to rapidly detect possible polluted seafood samples.

Temporal and spatial distributions of PBDEs in atmosphere at Shanghai rural regions, China

Atmospheric samples were collected using polyurethane foam (PUF) passive air sampling device for every 3 months from June 2012 to May 2013 in Shanghai rural regions in order to investigate the concentrations, profiles, spatial distributions, and seasonal variations of polybrominated diphenyl ethers (PBDEs). Twelve PBDE congeners (BDE-17, BDE-28, BDE-47, BDE-49, BDE-66, BDE-85, BDE-99, BDE-100, BDE-138, BDE-153, BDE-154, and BDE-183) were measured and analyzed by GC-MS. The results showed that detectable PBDEs were examined in all air samples, which indicated that these pollutants are widespread in the research areas. The ∑₁₂PBDE concentrations in Shanghai rural air ranged from 4.49 to 77.5 pg m^-3, with mean value up to 26.7 pg m^-3. The highest concentration was found at Jinshan sampling site in summer (from June to August in 2012). Furthermore, among the PBDE compounds investigated, the most frequently detected and the major congeners were BDE-17, BDE-28, BDE-47, and BDE-99. And the lower brominated diphenyl ethers (accounting for 75.0%) were the majority of the PBDE congeners. Finally, the result of principal component analysis (PCA) revealed that the lower and higher brominated diphenyl ethers in Shanghai rural regions were emitted from different pollutant sources.

Occurrence of PBDEs and alternative halogenated flame retardants in sewage sludge from the industrial city of Guangzhou, China

This study investigated the prevalence and abundance of halogenated flame retardants (HFRs) in sludge samples from 5 sewage treatment plants in Guangzhou, China. Detection of 18 polybrominated diphenyl ethers (PBDEs), 9 alternative HFRs including Dechlorane Plus (DP), brominated alkylbenzenes, and polybrominated biphenyls, and 2 related degradation products was conducted. Decabromodiphenyl ether (BDE 209) and decabromodiphenyl ethane (DBDPE) were the dominant HFRs, with concentrations ranging from 200 to 2150 ng/g and 680-27,400 ng/g, respectively. The DBDPE detected was the highest level reported so far, exceeding those previously reported by 10-100 times. PBDEs were surpassed as the dominant HFRs in sewage sludge, with mean DBDPE/BDE 209 ratio exceeding 2 in all samples. The review of earlier surveys reveals that DBDPE level was surging while BDE 209 was declining. Annual emissions of BDE 209, DP, and DBDPE were estimated to be 227.9, 10.5, and 979.3 kg/yr, respectively. Although ecological risks assessment suggested low risks for the examined sludge, the key environmental properties and transformation pathways of alternative HFRs remain largely unknown. These findings prompt for further investigations on alternative HFR and sustainable management practices for HFR-laden biosolids. The HFR emission pattern revealed in this study is likely representative of other similarly industrialized regions in the post-PBDE era.

On the sources of PBDEs in coastal marine sediments off Baja California, Mexico

Polybrominated diphenyl ethers (PBDEs) are widely distributed compounds in all types of matrices. In the northern portion of the Southern California Bight (SCB), there were reports of some of the largest PBDE concentrations in marine mammals and mussels. Because of this, we decided to analyze the status of PBDEs in the southern part of the SCB. An analysis of 91 samples of marine surface sediment was carried out. All of the 91 samples contained measurable amounts of PBDEs, which is a manifestation of the widespread distribution of these chemical substances. However, the levels detected are between one and two orders of magnitude smaller than those reported in southern California. Currents appear to control the distribution of PBDEs along the coast and the sedimentation sites with largest concentrations are favored by local bathymetry. Maximum concentrations were located in the middle and deeper platforms ranging from 0.02 to 5.90 (with a median 0.71) ng·g(-1) d.w. Deca-BDE mixture is largely predominant in the sediments followed by the penta-BDE mixture. The mass balance for the latitudinal strata shows the largest concentrations in the north where the largest population centers are present and with a very clear southward gradient. The mass balance calculation values showed about 36kg of PBDEs for the north, 22kg for the center, and 10kg for the south strata. In terms of depth, the PBDEs are mainly located on the middle and deep platforms rather than near point discharges, which is different than that reported by other authors.

Atmospheric occurrence and gas-particle partitioning of PBDEs at industrial, urban and suburban sites of Thessaloniki, northern Greece: Implications for human health

Air samples were collected during the cold and the warm period of the year 2012 and 2013 at three sites in the major Thessaloniki area, northern Greece (urban-industrial, urban-traffic and urban-background) in order to evaluate the occurrence, profiles, seasonal variation and gas/particle partitioning of polybrominated diphenyl ethers (PBDEs). The mean total concentrations of particle phase ∑12PBDE in the cold season were 28.7, 19.5 and 3.87 pg m(-3) at the industrial, urban-traffic and urban-background site, respectively, dropping slightly in the warm season (23.7, 17.5 and 3.14 pg m(-3)), respectively. The corresponding levels of gas-phase ∑12PBDE were 14.4, 7.15 and 4.73 pg m(-3) in the cold season and 21.2, 11.1 and 6.27 pg m(-3) in the warm season, respectively. In all samples, BDE-47 and BDE-99 were the dominant congeners. Absorption of PBDEs in the organic matter of particles appeared to drive their gas/particle partitioning, particularly in the cold season. The estimated average outdoor workday inhalation exposure to ∑12PBDE in the cold and the warm period followed the order: industrial site (288 and 299 pg day(-1)) > urban-traffic site (178 and 191 pg day(-1)) > urban-background site (58 and 63 pg day(-1)). The exposures to BDE-47, BDE-99, BDE-153 and ∑3PBDE via inhalation, for children outdoor worker and seniors were several orders of magnitude lower than their corresponding oral RfD values.

Review on the occurrence and profiles of polybrominated diphenyl ethers in the Philippines

The environmental occurrence of polybrominated diphenyl ethers (PBDEs) has been a subject of concern for the past decade because they are persistent, bioaccumulative, and toxic. These compounds have been listed as persistent organic pollutants (POPs) by the Stockholm Convention and are expected to disperse in the global environment even after their use and production. While the occurrence of PBDEs has been well characterized in environmental and biological samples from North America, Europe, and some Asian countries (i.e. China, Japan, and Korea), there is a scarcity of available data in developing Asian countries, such as the Philippines. Examination of PBDE contamination in the Philippine environment is particularly important because regulations have only recently been implemented on the production and use of PBDEs in this country. Additionally, the Philippines receives e-waste from Western countries, which is becoming a major source of organic contaminants in the tropical Asian regions. Ultimately, the Philippines may be a hot spot for contributing to on-going global PBDE pollution due to long-range atmospheric transport. This paper presents a review of the available literature on PBDEs in both environmental and biological samples collected from the Philippines. It is also intended to provide an overview on the levels and congener profiles of PBDEs in samples from the Philippines and to compare these data with other Asian countries. New data are presented on PBDE occurrence and congener profiles in fish commonly consumed by Filipinos and in particulate matter samples collected in Metro Manila, the capital of the Philippines. Both studies contribute to the available knowledge of PBDEs in the Philippines. We aim to stress the importance of future studies in countries receiving e-wastes, such as the Philippines, and suggest what future directions might be taken to enhance the available data on the presence of PBDEs in the Philippine environment.

Tracking the sources of polybrominated diphenyl ethers in birds: foraging in waste management facilities results in higher DecaBDE exposure in males

Differences in feeding ecology are now recognized as major determinants of inter-individual variations in contaminant profiles of free-ranging animals, but exceedingly little attention has been devoted to the role of habitat use. Marked inter-individual variations and high levels of polybrominated diphenyl ethers (PBDEs) (e.g., DecaBDE) have previously been documented in ring-billed gulls (Larus delawarensis) breeding in a colony near Montreal (QC, Canada). However, the environmental sources of these compounds, and thus the reasons causing these large inter-individual variations remain unidentified. In the present study, we used GPS-based telemetry (±5 to 10m precision) to track ring-billed gulls from this colony to reconstruct their movements at the landscape level. We related habitat use of individual gulls (n=76) to plasma concentrations (ng/g ww) and relative contributions (percentages) to Σ38PBDEs of major congeners in the internationally restricted PentaBDE and current-use DecaBDE mixtures. Male gulls that visited waste management facilities (WMFs; i.e., landfills, wastewater treatment plants and related facilities; 25% of all GPS-tracked males) exhibited greater DecaBDE (concentrations and percentages) and lower PentaBDE (percentages) relative to those that did not. In contrast, no such relationships were found in females. Moreover, in males, DecaBDE (concentrations and percentages) increased with percentages of time spent in WMFs (i.e., ~5% of total foraging time), while PentaBDE (percentages) decreased. No relationships between percentages of time spent in other habitats (i.e., urban areas, agriculture fields, and St. Lawrence River) were found in either sex. These findings suggest that animals breeding in the vicinity of WMFs as well as mobile species that only use these sites for short stopovers to forage, could be at risk of enhanced DecaBDE exposure.

Temporal and spatial contamination of polybrominated diphenyl ethers (PBDEs) in wastewater treatment plants in Hong Kong

Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants which cause adverse effects to human health and environments. Wastewater treatment plants (WWTPs) receive PBDEs from various discharges but also release them back to the environment via treated effluent and sludge, depending on the removal efficiency of WWTPs. This study investigated the contamination of PBDEs in primary influent, final effluent and dewatered sludge in four WWTPs in Hong Kong from October 2011 to January 2013. Results showed that the concentrations and composition profiles of eight PBDE congeners (BDE-28, －47, －99, －100, －153, －154,－183 and －209) differed among WWTPs and fluctuated during the study period. Higher concentrations of PBDEs were detected in the influent and dewatered sludge from the two WWTPs receiving both domestic and industrial wastewaters than the two serve mainly residential and commercial districts. However, the PBDE concentrations in the effluent were comparable among WWTPs. The concentrations of Σ8PBDEs (total of eight congeners) in the influent of all WWTPs ranged from 1 to 254 ng L(-1) but decreased to 12-27 ng L(-1) in effluent, with removal efficiency ranged from 20 to 53%. High concentrations of PBDEs, ranging from 9 to 307 ng g(-1) dry weights, were detected in dewatered sludge. The predominated congeners in influent were BDE-47 and -209 but shifted to BDE-47 and －99 in effluent and BDE-209 in dewatered sludge. Every day, it is estimated 0.66-73 g PBDEs entered the four WWTPs, while 0.38-38 g and 0.17-17 g PBDEs were discharged to the surrounding waters via effluent and disposed to landfill sites in sludge form, respectively. These results indicated that the four WWTPs in Hong Kong were not designed for effectively removal of PBDEs, 52-80% of the incoming PBDEs were still remained in effluent and 21-45% was precipitated in sludge, both outputs became significant contamination sources.

Atmospheric PBDEs at rural and urban sites in central China from 2010 to 2013: residual levels, potential sources and human exposure

Atmospheric polybrominated diphenyl ethers (PBDEs) were monitored monthly from 2010 to 2013 at rural and urban sites near a large shallow Chinese lake (Lake Chaohu). The urban areas had higher air PBDEs than the rural areas because of endogenic pollution. The highest and lowest concentrations of Σ13BDEs were observed in the winter and in the summer, respectively. A weak temperature dependence and significant positive correlations between certain PBDE congeners and the PM10 (p < 0.01) suggest transport with particulate matter. Using air-mass back-trajectories, we determined that the main sources of the PBDEs were the areas to the north, such as Shandong Province, and to the east, such as Zhejiang Province. PBDEs did not pose an appreciable risk to human health based on the inhalation exposure assessment. The residents in urban areas were exposed to higher levels of PBDEs, and wintertime exposures posed the greatest human health risk.

Polybrominated diphenyl ethers (PBDEs) in a conventional wastewater treatment plant (WWTP) from Shanghai, the Yangtze River Delta: implication for input source and mass loading

The concentrations of 19 polybrominated diphenyl ethers (PBDEs) congeners in a conventional wastewater treatment plant (WWTP) were determined to investigate the occurrence and fate of PBDEs during wastewater treatment processes. The level of total PBDEs ranged from 1.68 to 4.64 ng/L in wastewater, with BDE209 accounting for the largest proportion, followed by penta- and octa-BDE congeners. PBDEs were found to mainly exist in the particulate phase of wastewater, which rendered sedimentation efficient for the removal of PBDEs, while the removal efficiencies might be varied for congeners with different Br atom numbers. Because of similar congener profiles, in-house dust was considered to be an important source for PBDEs in the WWTP. According to the mass loading estimation, over 60% of total PBDEs entering the WWTP accumulated in the dewatered sludge, resulting in the total PBDE release of 43.8 kg/year via sewage sludge in Shanghai. And the annual release via effluent was estimated to be 5.5 kg, less but shouldn't be neglected.

Occurrence of polycyclic aromatic hydrocarbons in sludges from different stages of a wastewater treatment plant in Italy

The occurrence of polycyclic aromatic hydrocarbons (PAHs) in various sludge types from a moderate-big wastewater treatment plant in the Lombardy region, Italy, was studied. Pyrene was continuously the most abundant PAH, whereas anthracene was the PAH with the lowest concentrations. Average sigmaPAH concentrations ranged between 2405 ng/g (dry weight) in the secondary sludge and 2645 ng/g (dry weight) in the final sludge. A mass balance estimation between the various sludges showed no evident degradation of PAHs. The final sludge PAH concentrations were constantly at around half of the maximum permissible limit set by the European Union for use of sewage sludge in agriculture (6 mg/kg). The highest PAH concentrations were observed during the summer periods. Finally, two approaches were used to estimate the raw wastewater concentrations based on the sludge PAH concentrations. The values obtained did not differ much from the average concentrations measured at the influent wastewaters.

Environmental mass spectrometry

Environmental mass spectrometry is an important branch of science because it provides many of the data that underlie policy decisions that can directly influence the health of people and ecosystems. Environmental mass spectrometry is currently undergoing rapid development. Among the most relevant directions are a significant broadening of the lists of formally targeted compounds; a parallel interest in nontarget chemicals; an increase in the reliability of analyses involving accurate mass measurements, tandem mass spectrometry, and isotopically labeled standards; and a shift toward faster high-throughput analysis, with minimal sample preparation, involving various approaches, including ambient ionization techniques and miniature instruments. A real revolution in analytical chemistry could be triggered with the appearance of robust, simple, and sensitive portable mass spectrometers that can utilize ambient ionization techniques. If the cost of such instruments is reduced to a reasonable level, mass spectrometers could become valuable household devices.