| 1. |
- Cao, Zhiguo, et al.
(författare)
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Economic status as a determinant of national PCDD/PCDF releases and implications for PCDD/PCDF reduction
- 2013
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 91:3, s. 328-335
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Tidskriftsartikel (refereegranskat)abstract
- The annual releases of polychlorinated dibenzo-para-dioxins and polychlorinated dibenzofurans (PCDD/PCDF) from 68 countries/regions were investigated by correlating quantitative emissions with economic status of the nations. The national dioxin/furan inventories were developed using the PCDD/PCDF Standardized Toolldt, which presents the quantitative releases from ten major source groups to five release vectors. The correlation between intensity of PCDDIPCDF release and economic status was discussed and the influence of economic status on composition of five release vectors and ten source groups was studied. As PCDD/PCDF are mainly released from human activities to environmental matrices, release per person (RpP) and release per unit area (RpA) are defined to reflect release burden (Donor) and contamination burden (Receptor), respectively. Based on these two concepts, International PCDD/PCDF Reduction Burden is characterized by burden quotient (BQ) and a calculation model is established. The numbers of countries/regions with high, moderate and low International PCDD/PCDF Reduction Burden were 19,31 and 18, respectively. The information in this paper can be used for politicians to develop legislations to improve International PCDD/PCDF Reduction.
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| 2. |
- Meng, Pingping, et al.
(författare)
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Efficient removal of perfluorooctane sulfonate from aqueous film-forming foam solution by aeration-foam collection
- 2018
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Ingår i: Chemosphere. - : Elsevier BV. - 0045-6535 .- 1879-1298. ; 203, s. 263-270
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Tidskriftsartikel (refereegranskat)abstract
- Aqueous film-forming foams (AFFFs) used in fire-fighting are one of the main contamination sources of perfluorooctane sulfonate (PFOS) to the subterranean environment, requiring high costs for remediation. In this study, a method that combined aeration and foam collection was presented to remove PFOS from a commercially available AFFF solution. The method utilized the strong surfactant properties of PFOS that cause it to be highly enriched at air-water interfaces. With an aeration flow rate of 75 mL/min, PFOS removal percent reached 96% after 2 h, and the PFOS concentration in the collected foam was up to 6.5 mmol/L, beneficial for PFOS recovery and reuse. Increasing the aeration flow rate, ionic strength and concentration of co-existing surfactant, as well as decreasing the initial PFOS concentration, increased the removal percents of PFOS by increasing the foam volume, but reduced the enrichment of PFOS in the foams. With the assistance of a co-existing hydrocarbon surfactant, PFOS removal percent was above 99.9% after aeration-foam collection for 2 h and the enrichment factor exceeded 8400. Aeration-foam collection was less effective for short-chain perfluoroalkyl substances due to their relatively lower surface activity. Aeration-foam collection was found to be effective for the removal of high concentrations of PFOS from AFFF-contaminated wastewater, and the concentrated PFOS in the collected foam can be reused.
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| 3. |
- Meng, Pingping, et al.
(författare)
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Role of the air-water interface in removing perfluoroalkyl acids from drinking water by activated carbon treatment
- 2020
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Ingår i: Journal of Hazardous Materials. - : Elsevier BV. - 0304-3894 .- 1873-3336. ; 386
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Tidskriftsartikel (refereegranskat)abstract
- Contamination of drinking water by per- and polyfluoroalkyl substances (PFASs) is a worldwide problem. In this study, we for the first time revealed the role of the air-water interface in enhancing the removal of long-chain perfluoroalkyl carboxylic (PFCAs; CnF2n+1COOH, n >= 7) and perfluoroalkane sulfonic (PFSAs; CnF2n+1SO3H, n >= 6) acids, collectively termed as perfluoroalkyl acids (PFAAs), through combined aeration and adsorption on two kinds of activated carbon (AC). Aeration was shown to enhance the removal of long-chain PFAAs through adsorption at the air-water interface and subsequent adsorption of PFAA-enriched air bubbles to the AC. The removal of selected long-chain PFAAs was increased by 50-115 % with the assistance of aeration, depending on the perfluoroalkyl chain length. Aeration is more effective in enhancing long-chain PFAA removal as air-water interface adsorption increases with PFAA chain length due to higher surface activity. After removing adsorbed air bubbles by centrifugation, up to 80 % of the long-chain PFAAs were able to desorb from the sorbent, confirming the contribution of the air-water interface to the adsorption of PFAAs on AC. Aeration during AC treatment of water could enhance the removal of long-chain PFAAs, and improve the performance of AC during water treatment.
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| 4. |
- Wang, Bin, et al.
(författare)
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A primary estimate of global PCDD/F release based on the quantity and quality of national economic and social activities
- 2016
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Ingår i: Chemosphere. - Oxford, United Kingdom : Elsevier. - 0045-6535 .- 1879-1298. ; 151, s. 303-309
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Tidskriftsartikel (refereegranskat)abstract
- The correlations between polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) releases and factors relevant to human social-economic activities (HSEAs) were analyzed. The multiple linear regression model was successfully developed to estimate the total global PCDD/F release. The PCDD/F releases significantly correlated with population, area, GDP and GNI, suggesting that "quantity" of HSEAs have significantly contributed to the PCDD/F releases. On another aspect, advanced technologies are usually adopted in developed countries/regions, and hence reduce the PCDD/F release. The significant correlation between PCDD/F release and CO2 emission implies the potential of simultaneous reduction of CO2 emission and PCDD/F release. The total global PCDD/F release from 196 countries/regions was estimated to be 100.4 kg-TEQ yr(-1). The estimated annual PCDD/F release per unit area ranged from 0.007 to 28 mg-TEQ km(-2). Asia is estimated to have the highest PCDD/F release of 47.1 kg-TEQ yr(-1), almost half of the total world release. Oceania is estimated to have the smallest total release but the largest per-capita release. For the developed areas, such as Europe and North America, the PCDD/F release per unit GDP is lower, while for Africa, it is much higher.
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| 5. |
- Zhang, Tingting, et al.
(författare)
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Bioanalytical characterization of dioxin-like activity in sewage sludge from Beijing, China
- 2009
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Ingår i: Chemosphere. - : Elsevier. - 0045-6535 .- 1879-1298. ; 75:5, s. 649-653
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Tidskriftsartikel (refereegranskat)abstract
- In this preliminary study, the bioanalytical characterization of dioxin-like activity in the sludge of all the nine municipal sewage treatment plants from Beijing city Was Studied using chemically activated luciferase gene expression (CALUX) assay. The influence of heating period in winter, sewage and sludge treatment processes on the occurrence of dioxin-like activity was also discussed. For the use of clean coal and natural gas, heating did not have significant influence on the occurrence level of PCDD/Fs and dioxin-like-PCBs in this study. Anaerobic-aerobic-anoxic sewage treatment process did not show a good performance in the reduction of dioxin-like activity which is useful in the removal of chemical oxygen demand (COD) and nitrogen. Anaerobic digestion of sludge increased the concentration of PCDD/Fs from 30.1 to 68.3 pg CALUX-TEQ g(-1) d.w., and total dioxin-like activity from 32.2 to 69.3 pg CALUX-TEQ g(-1) d.w. This cost-effective and quick test is useful for large developing countries like China in monitoring programs to obtain baseline data about the scale of contamination caused by dioxin-like activity. It is also a useful component in the monitoring capacity building of dioxins.
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