In this study, the removal efficiency of PFCs(perfluorinated compounds) in the GAC(granule activated carbon) process based on the superheated steam automatic regeneration system was investigated in laboratory scale and pilot-scale reactor. Among PFCs, PFHxS(perfluorohexyl sulfonate) was most effectively removed. The removal efficiency of PFCs was found to be closely related to the EBCT, and the removal efficiencies of PFOA(perfluorooctanoic acid), PFOS(perfluorooctyl sulfonate), and PFHxS were 43.7, 75, and 100%, respectively, under the condition of EBCT of 6 min. Afterward, PFOA, PFOS, and PFHxS exhibited the earlier breakthrough time in the order. After that, GAC was regenerated, and the removal efficiency of the PFCs before and after regeneration was compared. As a result, it was shown that the PFCs removal efficiency in the regenerated GAC process were higher, and that of PFOA was improved to 75%. The findings of this study indicate the feasibility of the superheated steam automatic regeneration system for the stable removal of the PFCs, and it was verified that this technology can be applied stably enough even in field conditions.
본 연구는 국내 유통되는 액상 유제품에 함유된 17종의 과불화화합물 (PFCs) 함량에 대한 모니터링을 위해 수행되었다. 샘플을 액체-액체 추출을 통해 추출하고 LC-MS/ MS로 정량 분석하였다. 시중에 유통중인 98개의 액상 유제품 샘플에서 PFCs의 모니터링을 진행하였으며 그 결과, PFTeDA를 제외한 16종의 PFCs가 검출되었다. 총 PFCs의 함량은 0.9037 ng/mL로 액상 우유에서 가장 높았으며, PFPeA, PFDS, PFHxA도 액상우유에서 0.1 ng/mL 이상의 농도 수준을 보였다. 미국과 이탈리아에서 수행한 연구와 비교했을 때 PFOA와 PFOS의 잔류 패턴은 유사한 것으 로 나타났으며, 농도 수준은 0.1 ng/mL 미만이었다. 액상 유제품은 다양한 가공단계(살균, 혼합, 지방제거 등)를 거쳐 총 PFCs의 함량이 감소하는 것으로 보여지며, 특히 짧은 탄소 사슬을 가진 PFCs가 크게 감소하거나 검출되지 않았다. 이는 식품 안전에서 원료의 PFOS와 PFOA의 잔류정도가 중요하다는 것을 의미한다.
Adsorption by granule activated carbon(GAC) is recognized as an efficient method for the removal of perfluorinated compounds(PFCs) in water, while the poor regeneration and exchange cycles of granule active carbon make it difficult to sustain adsorption capacity for PFCs. In this study, the behavior of PFCs in the effluent of wastewater treatment plant (S), the raw water and the effluents of drinking water treatment plants (M1 and M2) located in Nakdong river waegwan watershed was monitored. Optimal regeneration and exchange cycles was also investigated in drinking water treatment plants and lab-scale adsorption tower for stable PFCs removal. The mean effluent concentration of PFCs was 0.044 0.04 PFHxS g/L, 0.000 0.00 PFOS g/L, 0.037 0.011 PFOA g/L, for S wastewater treatment plant, 0.023 0.073 PFHxS g/L, 0.000 0.00 PFOS g/L, 0.013 0.008 PFOA g/L for M1 drinking water treatment plant and 0.023 0.073 PFHxS g/L, 0.000 0.01 PFOS g/L, 0.011 0.009 PFOA g/L for M2 drinking water treatment plant. The adsorption breakthrough behaviors of PFCs in GAC of drinking water treatment plant and lab-scale adsorption tower indicated that reactivating carbon 3 times per year suggested to achieve and maintain good removal of PFASs. Considering the results of mass balance, the adsorption amount of PFCs was improved by using GAC with high-specific surface area (2,500m2/g), so that the regeneration cycle might be increased from 4 months to 10 months even if powdered activated carbon(PAC) could be alternatives. This study provides useful insights into the removal of PFCs in drinking water treatment plant.
The chemical structures of perfluorinated compounds(PFCs) have unique properties such as thermal and chemical stability that make them useful components in a wide variety of consumer and industrial products. Two of these PFCs, perfluorooctane sulfonate(PFOS) and perfluorooctanoic acid(PFOA), have received attention and were the most commonly detected. In this study it was analyzed the concentrations of 8 PFCs in samples were collected from drinking water treatment plants for 5 years(2012-2016). PFOS and PFOA were also high concentration and frequency. The mean concentrations of PFOA and PFOS were detected 0.0026-0.0069 μg/L and 0.0009-0.0024 μg/L in samples from drinking water treatment plants. These were relatively lower or similar compared to PFOS concentrations in Osaka(Japan). In general, these levels are below health-based values set by international authoritative bodies for drinking water. These results will be serve as the first monitoring data for PFCs in drinking water and be useful for characterizing the concentration distribution and management of PFCs in future studies.
Water, plankton, blood and liver of crucian carp (Carassius auratus) and mandarin fish (Siniperca cherzeri) samples from 5 freshwater ecosystems in 3 major rivers of Korea including Nam Han River, Nakdong River and Yeongsan River were collected.
Raw leachates from three landfills and treated leachates from two landfills on Jeju Isalnd were analyzed for ten perfluorinated compounds (PFCs) detected in aquaruc environments. The leachates were collected six times in 2014 and 2015. Among the ten PFCs, three were not detected, namely perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), and perfluorodecane sulfonate (PFDS). The total concentrations of PFCs ranged as 724-3313 ng/L (mean 1999 ng/L) in raw leachates and from less than the limit of quantification (LOQ) to 394 ng/L (mean 133.2 ng/L) in treated leachates. The domonant compounds measured were perfluorooctanoic acid (PFOA) (mean contribution 37.7%) and perfluorobutane sulfonate (PFBS) (mean contribution 38.2%) in raw leachates, and PFOA (mean contribution 40.7%), perfluorohexanoic acid (PFHxA) (mean contribution 27.3%) and PFBS (mean contribution 26.5%) in treated leachates. No significant correlations were observed between total/several individual PFCs and leachate pH and CODCr, which may be due to complex chemical nature of landfill leachates and characteristics of waste and landfills.
PFCs는 독특한 사용감과 특성으로 인하여 화장품에 응용되어질 때 많은 특장점을 가지고 있다. 그러나 이러한 장점에도 불구하고 화장품 제형에 적용하기에 많은 어려움을 가지고 있다. 즉, 물과 오일에 불용성, 높은 비중, 높은 증기압 등과 같은 원료의 특징으로 인하여 PFCs는 화장품에 적용하기 위하여 특별한 안정화 시스템을 필요로 한다. 본 연구에서 PFCs를 안정화하기 위하여 gel network, spherulite lamellar, nanosturucture 이상의 세 가지 시스템을 이용하였으며 사용된 세 가지 시스템 중 nanostructure system이 가장 안정함을 알 수 있었다.