Long-term nationwide assessment of polychlorinated dibenzo-p-dioxins/dibenzofurans and dioxin-like polychlorinated biphenyls ambient air concentrations for ten years in South Korea.

In this study, seasonal/regional variations of Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and dioxin like-polychlorinated biphenyls in the ambient air were monitored for ten years (2008-2017) using a high volume air sampler. As a result of strict regulation enforced by Korea Ministry of Environment in 2008, PCDD/DFs concentrations in the ambient air decreased from 0.051 pg I-TEQ Sm-3 in 2009 to 0.014 pg I-TEQ Sm-3 in 2017 which was comparably associated with cut-down of their emission sources from 880.2 g I-TEQ Sm-3 in 2001 to 24.2 g I-TEQ Sm-3 in 2015; revealing that it was only 2.7% against that of 2001. In 2017, mean TEQ concentration level of PCDD/DFs in the air of South Korea was quite low in comparison to its ambient environmental standards of 0.6 pg I-TEQ Sm-3 for PCDD/DFs. Particularly, the sum of PCDD/DFs in the background revealed the lowest level, however, the fraction of octachlorodibenzodioxin among other isomers exposed at the highest level in this study, suggesting that the ambient air quality in the background being studied was severely and persistently impaired by inflowing unknown sources of any possible anthropogenic transboundary migratory air pollutants. Moreover, this study conducted the scientific analysis of the long-term variations in the ambient air and emission sources using principal component analysis. From this of 10 years long-term nationwide assessments for the PCDD/DFs and dl-PCBs in the ambient air, it is possible to prove that South Korean environmental policy to manage POPs has been successfully conducted for the last ten years.

Destruction behavior of short- and medium-chain chlorinated paraffins in solid waste at a pilot-scale incinerator.

Incineration experiments with solid wastes containing approximately 3% (w/w) short-chain chlorinated paraffins (SCCPs) that have recently been listed as persistent organic pollutants (POPs) and medium-chain chlorinated paraffins (MCCPs) were conducted using a pilot-scale incinerator to investigate the efficiency of their destruction as well as the unintentional formation of POPs and their destruction behaviors during controlled incineration. A series of experiments demonstrated that SCCPs and MCCPs in solid wastes were progressively destroyed and removed during rotary kiln combustion and downstream flue gas treatments. Destruction efficiencies of SCCPs and MCCPs exceeding 99.9999% were confirmed. SCCPs in bottom and fly ash samples were present at levels below their quantification limits (0.021 and 0.31 mg/kg), and MCCPs in the bottom and fly ash samples were likewise present at concentrations below their quantification limits (0.034 and 0.50 mg/kg). Total concentrations of toxicity equivalency quantities (TEQs) for polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in emission gas samples collected at the bag filter exit and final exit were 0.083-0.30 and 8.7 × 10-7 to 1.3 × 10-4 ng-TEQ/m3N, respectively, and those in bottom and fly ash samples were 0.12-0.47 and 9.0 × 10-3 to 0.14 ng-TEQ/g, respectively. The results obtained in this study suggest that controlled incineration of solid wastes under the current regulations for incinerators in Japan and the countries with regulations and monitoring to minimize emissions of PCDDs/DFs and dl-PCBs is one of the best available technologies for the environmentally sound management of wastes containing SCCPs and MCCPs.

Polychlorinated dibenzo-p-dioxins, dibenzofurans and dioxin-like polychlorinated biphenyls in food and feed in Latvia in 2009-2011.

During 2009-2011 a monitoring programme for 17 polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and 12 dioxin-like polychlorinated biphenyls (DL-PCBs) was conducted in the Latvian food and feed market. Using ISO 17025-accredited analytical methodology, investigation of 121 food (milk, dairy products, meat, eggs, fish, fish products) and 66 feed samples (fish meal and oil, compound and mineral feed, vegetable and animal fats) was performed. Most samples showed contamination below the European Commission (EC) Regulation No. 1881/2006 and Commission Directive 2006/13/EC limits. Average total toxicological equivalent (total-TEQ(1998)) concentrations within the food sample groups, except fish and fish products, ranged between 0.41 and 15.1 pg total-TEQ(1998) g(-1) fat. Fish and fish products showed contamination levels from 0.18 to 46.0 pg total-TEQ(1998) g(-1) fresh weight (f.w.). Fifty-seven per cent of cod liver samples were non-compliant. The most contaminated feed samples were fish meal and fish oil. A comparison with WHO-TEF(2005) data is given.

Operating and environmental performances of commercial-scale waste gasification and melting technology.

Gasification technologies for waste processing are receiving increased interest. A lot of gasification technologies, including gasification and melting, have been developed in Japan and Europe. However, the flue gas and heavy metal behaviors have not been widely reported, even though those of grate furnaces have been reported. This article reports flue gas components of gasification and melting technology in different flue gas treatment systems. Hydrogen chloride concentrations at the inlet of the bag filter ranged between 171 and 180 mg Nm(-3) owing to de-acidification by limestone injection to the gasifier. More than 97.8% of hydrogen chlorides were removed by a bag filter in both of the flue gas treatment systems investigated. Sulfur dioxide concentrations at the inlet of the baghouse were 4.8 mg Nm(-3) and 12.7 mg Nm(-3), respectively. Nitrogen oxides are highly decomposed by a selective catalytic reduction system. Owing to the low regenerations of polychlorinated dibenzo-p-dioxins and furans, and the selective catalytic reduction system, the concentrations of polychlorinated dibenzo-p-dioxins and furans at the stacks were significantly lower without activated carbon injection. More than 99% of chlorine is distributed in fly ash. Low-boiling-point heavy metals, such as lead and zinc, are distributed in fly ash at rates of 97.6% and 96.5%, respectively. Most high-boiling-point heavy metals, such as iron and copper, are distributed in metal. It is also clarified that the slag is stable and contains few harmful heavy metals, such as lead. The heavy metal distribution behaviors are almost the same regardless of the compositions of the processed waste. These results indicate that the gasification of municipal solid waste constitutes an ideal approach to environmental conservation and resource recycling.