Thermal utilization techniques and strategies for secondary aluminum dross: A review.

Secondary aluminum ash (SAD) disposal is challenging, particularly in developing countries, and presents severe eco-environmental risks. This paper presents the treatment techniques, mechanisms, and effects of SAD at the current technical-economic level based on aluminum ash's resource utilization and environmental properties. Five recovery techniques were summarized based on aluminum's recoverability in SAD. Four traditional utilization methods were outlined as per the utilization of alumina in SAD. Three new utilization methods of SAD were summarized based on the removability (or convertibility) of aluminum nitride in SAD. The R-U-R (recoverability, utilizability, and removability) theory of SAD was formed based on several studies that helped identify the fingerprint of SAD. Furthermore, the utilization strategies of SAD, which supported the recycling of aluminum ash, were proposed. To form a perfect fingerprint database and develop various relevant techniques, future research must focus on an extensive examination of the characteristics of aluminum ash. This research will be advantageous for addressing the resource and environmental challenges of aluminum ash.

Occurrence and formation pathways analysis of PBDD/Fs from 2,4,6-tribromophenol under thermal reaction conditions.

Polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) are highly toxic and persistent compounds that provoke a wave of publicity. Bromophenols are important precursors for forming PBDD/Fs, and their reaction path has always been a research hotspot. In this study, the formation characteristic of PBDD/Fs from 2,4,6-TBP were studied. The yields of 2,3,7,8-substituted PBDD/Fs and 2,4,6,8-TBDF for the different thermal products ranged from 0.067 to 10.3 ng/g and 0.207-9.68 ng/g, respectively. The effects of adding Cu, Fe, and Sb2O3 were investigated and found to be more inclined to accelerate the formation of ortho-substituted PBDD/Fs than 2,3,7,8-PBDD/Fs. The formation pathways of 2,3,7,8-substituted PBDD/Fs and 2,4,6,8-TBDF were also proposed. 2,4,6,8-TBDF is generated in the C-C coupling reactions of some radical intermediates from the debromination of 2,4,6-TBP. The 2,3,7,8-PBDD/Fs are produced through more complex debromination, bromine substitution, and bromine rearrangement reactions. In addition, various catalytic effects on PBDD/F formation pathways were found, and the catalytic effect of Cu by the Ullmann reaction was the highest, while bromophenol oxidation by Fe was the highest. These results proved that both 2,3,7,8-substituted and non-2,3,7,8-substituted PBDD/Fs would be generated from 2,4,6-TBP, and the effects of the catalyst on the Br substituted position of 2,3,7,8-substituted PBDD/Fs were much lower than the Br-substituted position on bromophenol.

Characterizing the emission behaviors of cumulative VOCs from automotive solvent-based paint sludge.

Volatile organic compounds (VOCs) diffused from paint sludge are potential hazard contributing significantly to environmental pollution and exposure to them can cause severe health issues. In this paper, a diffusion-controlled model was firstly developed for characterizing the emission behaviors of cumulative VOCs from automotive solvent-based paint sludge based on the worst field management scenario. The presented model is characterized by two key parameters: the diffusion coefficient (Dm) and the initial emittable concentration (Cm,0), which can be simultaneously obtained by our proposed ER-history method. Four major components were detected including 1-butanol, butyl acetate and 1,2,4-trimethylbenzene and 1-ethyl-4-methylbenzene. In addition, the model was validated by using environmental data in a ventilated test chamber, proving that the model is reliable and convincing. However, relative deviations of 1-butanol and butyl acetate are larger than those of 1,2,4-trimethylbenzene and 1-ethyl-4-methylbenzene, indicating that the model is more accurate for predicting hydrophobic VOCs release than those of hydrophilic VOCs. Besides, an increase in Cm,0 and Dm tends to enhance VOCs cumulation release. Our studies provide new insight into experimental designs for rapid model parameters measurement and a sound basis for estimating VOCs cumulative release from paint sludge as well as for hazardous waste.

Spatial distribution of and seasonal variations in endosulfan concentrations in soil, air, and biota around a contaminated site.

Soil, air, tree bark, rice, wheat, invertebrates, and chicken tissues around a typical endosulfan-contaminated site were analyzed in each season in each of two years. The total endosulfan (the sum of α-, ß-endosulfan and endosulfan sulfate) were significantly different in soil and air samples collected in the four seasons (P < 0.01) and the mean concentrations were 6.53 ng/g dry weight (d.w.) and 2.40 ng/m3, respectively, in autumn, 3.32 ng/g d.w. and 2.48 ng/m3, respectively, in winter, 2.10 ng/g d.w. and 0.93 ng/m3, respectively, in spring, and 1.03 ng/g d.w. and 0.83 ng/m3, respectively, in summer. The total endosulfan concentrations in tree bark, rice, wheat, and invertebrates were 23.0-278 (mean 95.5) ng/g d.w., 7.36-35.5 (mean 17.4) ng/g d.w., 34.3-158 (mean 83.1) ng/g d.w., and 401-4354 (mean 2125) ng/g lipid weight, respectively. The total endosulfan concentrations in the chicken gizzard, heart, liver, and meat samples were 552, 212, 699, and 221 ng/g lipid weight, respectively. The endosulfan concentrations in soil, air, and biota around the site were strongly influenced by endosulfan emissions from the site, and the concentrations had decreased to half the initial concentrations six months after endosulfan production stopped. The invertebrate and chicken bioconcentration and biomagnification factors indicated that endosulfan accumulated in the invertebrates and chicken tissues was slightly biomagnified by chickens.

Characteristics of solid waste from common generation source in nonferrous smelting industry reveal a new classification method.

Solid waste produced by the nonferrous smelting industry has a significant number of notable differences. The lack of recognition of solid waste characteristics is the main factor restricting its disposal and utilization. In this study, we analyzed the main production processes of the nonferrous smelting industry; identified the key production nodes of solid waste; and clarified the characteristics, including the physical, chemical, and pollution characteristics of solid wastes, through a large sample statistical analysis. We found similarities among solid wastes from a common generation source as well as notable differences among the different generation sources: slags and sludges from waste acid treatment and wastewater treatment units had a water content of 27.43-52.71% and 51.14-68.27%, respectively, which were significantly higher than those of other metallurgy and dust collection units; the pH of slags from an electrorefining unit was strongly alkaline; the mineral phase of sludges from wastewater treatment was only calcite; slags from a waste acid treatment unit were mainly in phase of gypsum, claudetite, and anglesite; the chemical composition of slags from pyrometallurgy and hydrometallurgy units was mainly SiO2 and Fe2O3. In this paper, we discuss a new classification method based on a common generation source for the first time. These results are beneficial to guide the disposal, utilization, and management of solid waste.

Free radical formation via BDE-209 thermolysis in the precalciner of a cement kiln: Simulation and DFT study.

To deeply understand the formation mechanism of polybrominated dibenzo-p-dioxins/furans (PBDD/Fs) in the thermal disposal process of polybrominated diphenyl ether (PBDE)-containing waste, this paper studied the formation pathways of key intermediates (free radicals, FRs) in the formation process of PBDD/Fs. BDE-209, the most common PBDE in the environment, was selected as the object of study to analyze FR formation by simulating the key conditions such as temperature (850 °C) and Fe-based materials when PBDE-containing waste entering cement kiln precalciner. Electron paramagnetic resonance (EPR) spectroscopy and density functional theory (DFT) calculations were used to study the reaction. The result of simulation experiments revealed carbon-centered radicals, and DMPO-OH analysis further confirmed the generation of FRs. The findings confirmed previous calculations predicting the existence of radical intermediates during the formation of PBDD/Fs from BDE-209. DFT calculations revealed the existence of an inner ortho-position CBr bond in BDE-209. The priority order of the bond breaking of BDE-209 was ether bond, inner ortho-position CBr bond, and outside ortho-position CBr bond. BDE-209 can further form three kinds of FRs, namely, oxygen-centered radicals of single benzene rings, carbon-centered radicals of single benzene rings, and carbon-centered radicals of double benzene rings. The specific processes of FR formation were inferred: high-temperature homogeneous cleavage of chemical bonds, electron transfer, and chemisorption, where electron transfer and chemisorption may be more important pathways. The proposed inner ortho-position cleavage within BDE-209 provides new insights into the degradation of PBDEs and the formation of PBDD/Fs; the results regarding BDE-209 generation radicals further elucidate the synthesis mechanism of dioxins, which is important for controlling dioxin generation and emission during the treatment and disposal of waste containing PBDEs.

PCDD/Fs emissions from secondary copper production synergistically controlled by fabric filters and desulfurization.

The effects of fabric filters and desulfurization systems during secondary copper smelting on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) concentrations, emission coefficients, and profiles were studied in an oxygen-rich smelting furnace and an anode furnace. In the anode furnace, the toxic equivalent (TEQ) concentration ranges were 0.106-1.04 ng World Health Organization (WHO)-TEQ/m3 at the fabric filters inlet and 0.027-0.17 ng WHO-TEQ/m3 at the outlet. For the oxygen-rich smelting furnace, the TEQ concentration ranges were 1.21-1.93 and 0.010-0.019 ng WHO-TEQ/m3 at the desulfurization system inlet and outlet, respectively. The TEQs in the outlet stack gases of the desulfurization system from the anode furnace were 0.0041-0.016 ng WHO-TEQ/m3. It is likely that PCDD/Fs that were taken away from the stack gases were adsorbed by the fly ash and gypsum. Solid residues were the dominant release routes for PCDD/Fs. PCDD/Fs congener and homologue profiles of stack gases from different smelting stages were similar. The contributions of more chlorinated homologues from the anode furnace decreased observably after the stack gases passed through the fabric filters. However, the desulfurization process did not greatly change the PCDD/Fs homologue profiles. Overall, both the fabric filters and desulfurization systems showed excellent removal efficiencies for PCDD/Fs in the stack gases, which reduced the TEQ emissions to well below the 0.5 ng WHO-TEQ/m3 to achieve standard discharge.

Occurrence of dioxin-like POPs in soils from urban green space in a metropolis, North China: implication to human exposure.

Urban green space is a special space for urban life and natural contact and has an important impact on human health. However, little information is available on dioxin-like persistent organic pollutants (POPs) in the soils from the specific areas. We measured the concentrations of polychlorinated naphthalenes (PCNs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polychlorinated biphenyls (PCBs) in the soils from urban green space in a metropolis, North China, and found total concentrations of PCDD/Fs, PCBs, and PCNs in the range of 11.5-91.4, 14.7-444, and 82.5-848 pg/g, respectively. It was worth to notice that the concentrations of PCDD/Fs in public park soil from urban center were significantly higher than those in the road greenbelts and resident lawns (Kruskal-Wallis test, p = 0.004). The source analysis indicated that sewage sludge from wastewater treatment plants were important sources of PCNs and PCDD/Fs in urban green land soils, and atmospheric deposition from municipal solid waste incinerator (MSWI) also play an important role in PCDD/F sources. The rough exposure risk evaluation showed that the residents were at a safe level with the daily doses being 0.172-3.144 fg/kg BW/day for children and 0.022-0.406 fg/kg BW/day for adult. Due to the complex and variable sources of PCDD/Fs in urban areas, dioxin-like POPs in urban green land should be given more attention to weaken human exposure.

Concentrations and occupational exposure assessment of polybrominated diphenyl ethers in modern Chinese e-waste dismantling workshops.

In this work, the concentrations of polybrominated diphenyl ethers (PBDEs) were determined in air, dust and fly ash samples from three legal waste electrical and electronic equipment dismantling plants with strict pollution controls. The risks posed by PBDEs to workers at the plants were assessed. The atmospheric concentrations of PBDEs in the different e-waste recycling workshops were 0.58-2.89 × 103 ng/m3, and predominantly distributed in the particle phase (90.7%-99.9%). The concentrations of the PBDEs in the floor dust and fly ash samples from bag-type dust collectors in different workshops were 2.39-125 µg/g, 5.84-128 µg/g, respectively. The contributions of BDE-209 in air, floor dust and fly ash samples were 84.0%-97.9%, 11.2%-95.3% and 74.0%-94.9%, respectively, indicating that deca-BDE commercial formulations were their major sources. Daily exposure to PBDEs was also lower than has been found for workers in other recycling workshops. Human exposures to BDE-47, BDE-99, BDE-153, and BDE-209 were all below the levels considered to pose appreciable risks. Dust ingestion was the main exposure route for manual recyclers, and inhalation was the main exposure route for waste transportation workers. The results of this study indicate that PBDEs emissions and risks are lower in modern, legal e-waste recycling facilities with effective pollution controls. However, the effectiveness of the pollution controls need to be further researched in plastic crushing areas.

Polychlorinated naphthalene emissions to the atmosphere from typical secondary aluminum smelting plants in southwestern China: concentrations, characterization, and risk evaluation.

Secondary aluminum smelting industry, as an important source of polychlorinated naphthalene (PCN) in environment, has been concerned in recent years. To figure out the emission characteristics of PCNs and the potential influence on surrounding environment, two typical secondary aluminum smelting plants were selected and PCNs were determined in flue gas, fly ash, aluminum slag, soil, and air samples collected at and around the plants by GC-MS coupled with DFS. PCN emission factors from the flue gas of the two plants (mean 0.006 ng toxic equivalents/t) were found obviously decreased compared with similar smelting process detected in 2010. The stage of feeding material was still the major PCNs discharge period during the whole smelting process. The total PCN concentrations in air were found to be ranked as following: workshops (290-1917 pg/m3), the area near the workshops (62.3-697 pg/m3), and the surrounding areas (29.9-164 pg/m3, mean 64.5 pg/m3). Similar high concentrations of PCNs were found in soil from by the workshop door (983 ng/g dry weight). Soil-air exchange calculations indicated that mono-CN to tetra-CN would volatilize but hepta-CN and octa-CN would be deposited to the soil. Exposure of plant workers and local inhabitants to PCNs through inhalation was found to be acceptable but higher (especially for workers in the workshops) than living areas. The workshop and the nearby area are potential PCNs polluted areas and should be paid attention during the practical operation.

Leaching of metals from asphalt pavement incorporating municipal solid waste incineration fly ash.

Rising municipal solid waste incineration (MSWI) makes it imperative to recycle the fly ash (FA). FA can be solidified by asphalt and then applied in the asphalt road. However, little information on the metal leaching and associated with risks from asphalt solidified forms for FA is available. In the present study, metal leaching characteristics and long-term leaching potential from the asphalt-based FA matrices was determined based on the national standard method and simulating the actual using of the solidified forms in highways, respectively. The immobilization effect of asphalt on MSWI FA is well. Leaching velocity was in the order of magnitude of 10~10-6 cm h-1 during the entire leaching period. At the early age, leaching velocity of metals is high, especially Zn, Cd, and Ba. Cumulative leaching concentration of metals and leaching time has positive correlation. Only considering the leaching of simulating acid, leaching of metals in asphalt-based matrices is very slow, and the leaching toxicity of metals is lower than the Chinese National Standard.

Chemical speciation of lead in secondary fly ash using X-ray absorption spectroscopy.

In this study, fly ash samples were collected from bag houses in a Chinese municipal solid waste incinerator (MSWI) and secondary fly ash (SFA) samples were collected from a high-temperature tubular electric furnace by thermal treatment of MSWI fly ash at 1050, 1100, 1150, 1200, and 1250 °C.We determined the speciation and atomic coordinates of lead in SFA using X-ray absorption spectroscopy (XAS) techniques. The results obtained by X-ray absorption near edge structure (XANES) spectra revealed that the mass fraction of PbO in MSWI fly ash was 57.9% (wt %) while PbCl2 and PbS were the dominant species in SFA. Extended X-ray absorption fine structure (EXAFS) data analysis indicated the atomic coordinates of Pb were proportional to the weights of PbCl2 and PbS, in good agreement with the XANES spectra. These findings highlight lead evaporation processes in the MSWI fly ash during heat treatment and provide a method for consistent speciation analysis of environmental samples using XAS.

Assessment of the temporal and spatial distribution of atmospheric PCNs and their air-soil exchange using passive air samplers in Shanghai, East China.

A total of 47 passive air samples and 25 soil samples were collected to study the temporal trend, distribution, and air-soil exchange of polychlorinated naphthalenes (PCNs) in Shanghai, China. Atmospheric PCNs ranged from 3.44 to 44.1 pg/m3 (average of 21.9 pg/m3) in summer and 13.6 to 153 pg/m3 (average of 40.0 pg/m3) in winter. In the soil samples, PCN concentrations were 54.7-1382 pg/g dry weight (average of 319 pg/g). Tri-CNs and tetra-CNs were two dominant homolog groups in air samples, while di-CNs were also found at comparable proportions to tri-CNs and tetra-CNs in soil samples. Most air and soil samples from the industrial and urban areas showed higher PCN concentrations than those from suburban areas. However, some soil samples in urban centers presented higher PCN concentrations than industrial areas. Analysis of PCN sources indicated that both industrial thermal process and historical usage of commercial PCN mixtures contributed to the PCN burden in most areas. The fugacity fraction results indicated a strong tendency of volatilization for lighter PCNs (tri- to hexa-CNs) in both seasons, and air-soil deposition for octa-CNs. Moreover, air-soil exchange fluxes indicate that soil was an important source of atmospheric PCNs in some areas. The results of this study provide information for use in the evaluation of the potential impact and human health risk of PCNs around the study areas.

Organochlorine pesticides in soil, air, and vegetation at and around a contaminated site in southwestern China: Concentration, transmission, and risk evaluation.

Remediation and management of contaminated sites have become a prevalent problem under the current situation in China. The present study was conducted to investigate the concentration, transmission, and health risk of organochlorine pesticides (OCPs) in soil, air, and vegetation at and around a typical pesticide-contaminated site located in southwestern China. Exchange flux between soil and air was calculated to investigate the transmission of OCPs. Hexachlorocyclohexane (ΣHCHs, top soil: 19.1 mg/kg d.w., air: 52.3 ng/m3, vegetation: 0.17 mg/kg d.w.) and dichlorodiphenyltrichloroethane (ΣDDTs, top soil: 200 mg/kg d.w., air: 130 ng/m3, vegetation: 0.78 mg/kg d.w.) were the dominant pollutants at the contaminated site. Around the site, the soil, air, and vegetation samples had higher OCP concentrations than those in the normal areas, which were found to be dominated by ΣHCHs (top soil: 129 ng/g d.w., air: 5.09 ng/m3, vegetation: 81.8 ng/g d.w.) and ΣDDTs (top soil: 360 ng/g, air: 7.47 ng/m3, vegetation: 189 ng/g d.w.). The fugacity fractions of OCPs (>0.7) showed a net volatilization from soil into air, indicating that soil is an obvious pollution source for the atmosphere, especially at the site. Through human health risk evaluation, serious carcinogenic risk (CRn) and hazardous index (HIn) were found at the site (CRn: 7.4 × 10-6-1.04 × 10-4, HIn: 0.02 to 8.97) and the nearby areas (CRn: 3.37 × 10-6 for adults and 1.68 × 10-6 for children on average).

Spatial distribution, transport dynamics, and health risks of endosulfan at a contaminated site.

We analyzed concentrations, distribution characteristics, and health risks of endosulfan (α and ß isomers, and endosulfan sulfate) in soils (top soils and soil profiles) and air, at and around a typical endosulfan production site in Jiangsu, China. The air-soil surface exchange flux is calculated to investigate transport dynamics of endosulfan. Concentrations at the production site ranged from 0.01 to 114 mg/kg d.w. in soil and 4.81-289 ng/m(3) in air, with very high concentrations occurring at the location of endosulfan emulsion workshop. In the surrounding area, endosulfan was detected in all samples, with concentrations ranging from 1.37-415 ng/g d.w. in soil and 0.89-10.4 ng/m(3) in air. In the contaminated site, endosulfan concentrations fluctuated with depth in the upper soil layers, then decreased below 120 cm. Soil and air within a distance of 2.0 km appear to be affected by endosulfan originating from the site. Even the health risk at the location of the endosulfan emulsifiable solution workshop was over seven times the acceptable value, the risk to nearby adults and children was low.

Seasonal variations in concentrations, distributions, and air-soil exchange fluxes of dioxin-like polychlorinated biphenyls in Shanghai, China.

Dioxin-like polychlorinated biphenyl (dl-PCB) concentrations in ambient air and soil in Shanghai, China, were measured to allow seasonal and spatial differences in the dl-PCB concentrations, profiles, distributions, fugacity fractions, and air-soil fluxes to be determined. The toxic equivalent (TEQ) DL-PCB concentrations in the air were higher in summer (mean 9.46 fg m(-3), range 1.32-26.3 fg m(-3)) than in winter (mean 4.57 fg m(-3), range 1.55-10.9 fg m(-3)). The DL-PCB concentrations in air were different in different areas, and the concentrations decreased in the order industrial areas > commercial and residential areas > suburban areas > rural area. The mean DL-PCB concentration in soil was 0.25 pg TEQ g(-1) dry weight (dw) and the range was 0.05-0.90 pg TEQ g(-1) dw. The highest DL-PCB concentration in soil was found in a sample from a commercial/residential area. The DL-PCB fluxes were negative (-216 pg m(-2) h(-1) in summer and -41.1 pg m(-2) h(-1) in winter), and the fugacity fractions were below 0.5, indicating that dl-PCBs in Shanghai are deposited from the air to the soil in all seasons. The net fluxes were higher in summer than in winter, and the deposition fluxes were higher in industrial areas than in other areas in both summer and winter.

Seasonal and spatial distributions of atmospheric polychlorinated naphthalenes in Shanghai, China.

Air samples were collected in Shanghai during summer and winter 2013, and the gas and particulate concentrations of polychlorinated naphthalenes (PCNs) were measured. All 75 congeners were quantified and the corresponding toxic equivalents (TEQs) were calculated. PCN concentrations were higher in summer than winter, at 8.22-102 pg/m(3) (average of 61.3 pg/m(3)) in summer and 16.5-61.1 pg/m(3) (average of 37.7 pg/m(3)) in winter. Their seasonal TEQ values were in contrast, at 1.35-7.31 fg/m(3) (average of 3.84 fg/m(3)) in summer and 4.08-23.3 fg/m(3) (average of 8.80 fg/m(3)) in winter, because of the seasonal change in congener profiles. Tri-CNs were the predominant homologs in both the summer and winter samples. However, the major congeners in summer were PCNs containing less chlorine, but these decreased over winter. Air mass back trajectories suggested that wind direction over various sites was similar in the summer and winter seasons, yet there were clear seasonal variations in atmospheric PCN concentrations. Ratios of several characteristic congeners were calculated and the results indicated that the ratios varied only to a limited extent with PCN emissions profile from industrial thermal sources, but varied strongly with profiles of technical PCN and PCN contaminants in polychlorinated biphenyl mixtures. The results of principal component analysis suggest that local industrial thermal emissions (thermal processes containing waste incineration and secondary metal smelting processes) still play a considerable role in influencing the atmospheric PCNs in Shanghai.

Human health risk assessment of pesticide residues in market-sold vegetables and fish in a northern metropolis of China.

With growing concerns about food safety and stricter national standards in China, attention has focused on vegetables and fish as they are an important part of the Chinese daily diet, and pesticide residues can accumulate in these foodstuffs. The local consumption habits of vegetables and fish were determined using questionnaires distributed in the major regions of the northern metropolis. Then, the samples of fruit-like vegetables, leafy and root vegetables, and five species of fish (freshwater and marine) were collected from supermarkets and traditional farmers' markets in the city. The concentrations and profiles of pesticide residues (hexachlorocyclohexane (HCH), dichlorodiphenyl trichloroethane (DDT), and endosulfan) in the samples were determined and compared. For the vegetables, the concentration ranges of ΣDDT, ΣHCH, and Σendosulfan were not detectable (ND) to 10.4 ng/g fresh weight (f.w.), ND to 58.8 ng/g f.w., and ND to 63.9 ng/g f.w., respectively. For the fish samples, the corresponding values were 0.77-25.0 ng/g f.w., 0.02-1.42 ng/g f.w., and 1.22-22.1 ng/g f.w., respectively. Only one celery sample exceeded the maximum residue limits (MRLs) of HCH residues set by Chinese regulations (GB2763-2014). The estimated daily intakes (EDIs) and hazard ratios (HRs) were calculated using data from the recently published Exposure Factors Handbook for the Chinese Population. The EDIs and HRs showed that the levels of organochlorine pesticide (OCP) residues in vegetables and fish in this area are safe.

Environmental risks of HBCDD from construction and demolition waste: a contemporary and future issue.

Hexabromocyclododecane (HBCDD), as one of the most widely used brominated flame retardants (BFRs), is of great concern globally because of its persistence in the environment and negative impacts on humans and animals. HBCDD has been mainly used in flame-retarded expanded (EPS) and extruded (XPS) polystyrene foams for insulation in the construction industry. Most of these products will become a part of the construction and demolition (C&D) waste at the end of their life cycle (30-50 years) which is typically disposed of into landfills or incineration. However, the recycling of this material takes quite a low share compared with landfill and incineration. Consequently, high environmental risks will exist in these disposal approaches due to the HBCDD in C&D waste. Currently, XPS or EPS products containing HBCDD in the construction industry have not reached the end of their life cycle in most countries. Relatively little attention has been paid to this emergency issue by either the government or public. Furthermore, C&D waste is most likely disposed of by direct dumping, simple stacking, or open burning in developing countries. Therefore, this paper highlights the global environmental risks of HBCDD from C&D waste. Areas of research for key problems of HBCDD contained in C&D waste are suggested to help control and finally eliminate the impact.

The distribution and biomagnification of higher brominated BDEs in terrestrial organisms affected by a typical e-waste burning site in South China.

Soil, vegetation, and several terrestrial species including turtledove, chicken, goose, grasshopper, dragonfly, butterfly and ant, were collected from an area surrounding a typical e-waste burning site in South China. The samples were examined to investigate the levels, congener profiles, and biomagnification extent of polybrominated diphenyl ethers (PBDEs) that may be present in the environment as a result of the e-waste, which was processed in a crude recycling style. Elevated levels of Σ(21)PBDEs were found in the biota (101­4725 ng g(−1) lipid weight (lw)), vegetation leaf (82.9­319 ng g(−1) dry weight (dw)) and soil samples (5.2­22 110 ng g(−1) dw), indicating that PBDE contamination in the samples collected from the e-waste burning site may pose risks to the local terrestrial ecosystem and local populations. Higher BDE congeners, especially deca-BDE (BDE-209) were the dominant homologs in organisms and nonbiological matrices, followed by nona-BDE and octa-BDE. Biomagnification factors (BMFs) were calculated as the ratio of the lipid-normalized concentration in the predator to that in the prey. The highest BMF (3.4) was determined for BDE-153 in the grasshopper/turtledove food chain. Other higher brominated congeners, such as BDE-202, -203, -154, -183 and -209, were also biomagnified in the terrestrial food chain with BMFs of 1.7­3.3. BDE-47, -100, and -99 were not biomagnified in the examined food chains (BMFs < 1), which suggests that bioaccumulation and biotransformation of PBDEs in terrestrial ecosystems could be distinguished from those in aquatic ecosystems.