https://repository.kopri.re.kr/handle/201206/11543 2026-04-15T07:56:59Z 2026-04-15T07:56:59Z Spolaor, Andrea Burgay, Francois Fernandez, Rafael P. Turetta, Clara Cuevas, Carlos A. Kim, Kitae Kinnison, Douglas E. Lamarque, Jean-Francois de Blasi, Fabrizio Barbaro, Elena Corella, Juan Pablo Vallelonga, Paul Frezzotti, Massimo Barbante, Carlo Saiz-Lopez, Alfonso https://repository.kopri.re.kr/handle/201206/13620 2022-07-07T08:05:06Z 2021-10-05T00:00:00Z

Title: Antarctic ozone hole modifies iodine geochemistry on the Antarctic Plateau Authors: Spolaor, Andrea; Burgay, Francois; Fernandez, Rafael P.; Turetta, Clara; Cuevas, Carlos A.; Kim, Kitae; Kinnison, Douglas E.; Lamarque, Jean-Francois; de Blasi, Fabrizio; Barbaro, Elena; Corella, Juan Pablo; Vallelonga, Paul; Frezzotti, Massimo; Barbante, Carlo; Saiz-Lopez, Alfonso Abstract: Polar stratospheric ozone has decreased since the 1970s due to anthropogenic emissions of chlorofluorocarbons and halons, resulting in the formation of an ozone hole over Antarctica. The effects of the ozone hole and the associated increase in incoming UV radiation on terrestrial and marine ecosystems are well established; however, the impact on geochemical cycles of ice photoactive elements, such as iodine, remains mostly unexplored. Here, we present the first iodine record from the inner Antarctic Plateau (Dome C) that covers approximately the last 212 years (1800-2012 CE). Our results show that the iodine concentration in ice remained constant during the pre-ozone hole period (1800-1974 CE) but has declined twofold since the onset of the ozone hole era (~1975 CE), closely tracking the total ozone evolution over Antarctica. Based on ice core observations, laboratory measurements and chemistry-climate model simulations, we propose that the iodine decrease since ~1975 is caused by enhanced iodine re-emission from snowpack due to the ozone hole-driven increase in UV radiation reaching the Antarctic Plateau. These findings suggest the potential for ice core iodine records from the inner Antarctic Plateau to be as an archive for past stratospheric ozone trends.

2021-10-05T00:00:00Z Kim, Jun-Tae Choi, Yun-Jeong Barghi, Mandana Kim, Jeong-Hoon Jung, Jin-Woo Kim, Kitae Kang, Jung-Ho Lammel, Gerhard Chang, Yoon-Seok https://repository.kopri.re.kr/handle/201206/13002 2022-03-24T07:15:12Z 2021-03-05T00:00:00Z

Title: Occurrence, distribution, and bioaccumulation of new and legacy persistent organic pollutants in an ecosystem on King George Island, maritime Antarctica Authors: Kim, Jun-Tae; Choi, Yun-Jeong; Barghi, Mandana; Kim, Jeong-Hoon; Jung, Jin-Woo; Kim, Kitae; Kang, Jung-Ho; Lammel, Gerhard; Chang, Yoon-Seok Abstract: The occurrence and bioaccumulation of new and legacy persistent organic pollutants (POPs), organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polychlorinated naphthalenes (PCNs), hexabromocyclododecanes (HBCDs), and Dechlorane Plus (DPs) and their related compounds (Dechloranes) in an ecosystem on King George Island, Antarctica are investigated. The new and legacy POPs were widely detected in the animal samples collected from Antarctica, which included Limpet, Antarctic cod, Amphipods, Antarctic icefish, Gentoo and Chinstrap penguins, Kelp gull, and South polar skua. The trophic magnification factors indicated that the levels of PCNs and HBCDs, as well as the legacy POPs, were magnified through the food web, whereas DPs might be diluted through the trophic levels contradicting the classification of Dechloranes as POPs. This is one of the first extensive surveys on PCNs, HBCDs, and Dechloranes, which provides unique information on the distribution and trophic biomagnification potential of the new and legacy POPs in the Antarctic region.

2021-03-05T00:00:00Z Nguyen, Quoc Anh Kim, Bomi Chung, Hyun Young Nguyen, Anh Quoc Khuong Kim, Jungwon Kim, Kitae https://repository.kopri.re.kr/handle/201206/11974 2022-03-24T07:14:16Z 2021-01-01T00:00:00Z

Title: Reductive transformation of hexavalent chromium by ferrous ions in a frozen environment: mechanism, kinetics, and environmental implications Authors: Nguyen, Quoc Anh; Kim, Bomi; Chung, Hyun Young; Nguyen, Anh Quoc Khuong; Kim, Jungwon; Kim, Kitae Abstract: The transformation between hexavalent chromium (Cr6+) and trivalent chromium (Cr3+) has a significant impact on ecosystems, as Cr6+ has higher levels of toxicity than Cr3+. In this regard, a variety of Cr6+ reduction processes occurring in natural environments have been studied extensively. In this work, we investigate the reductive transformation of Cr6+ by ferrous ions (Fe2+) in ice at-20 degrees C, and compare the same process in water at 25 degrees C. The Fe(2+-m)ediated reduction of Cr6+ occurred much faster in ice than it did in water. The accelerated reduction of Cr6+ in ice is primarily ascribed to the accumulation of Cr6+, Fe2+, and protons in the grain boundaries formed during freezing, which constitutes favorable conditions for redox reactions between Cr6+ and Fe2+. This freeze concentration phenomenon was verified using UV-visible spectroscopy with o-cresolsulfonephthalein (as a pH indicator) and confocal Raman spectroscopy. The reductive transformation of Cr6+ (20 mu M) by Fe2+ in ice proceeded rapidly under various Fe2+ concentrations (20-140 mu M), pH values (2.0-5.0), and freezing temperatures (-10 to-30 degrees C) with a constant molar ratio of oxidized Fe2+ to reduced Cr6+ (3:1). This result implies that the proposed mechanism (i.e., the redox reaction between Cr6+ and Fe2+ in ice) can significantly contribute to the natural conversion of Cr6+ in cold regions. The Fe2+-mediated Cr6+ reduction kinetics in frozen Cr(6+)contaminated wastewater was similar to that in frozen Cr6+ solution. This indicates that the variety of substrates typically present in electroplating wastewater have a negligible effect on the redox reaction between Cr6+ and Fe2+ in ice; it also proposes that the Fe2+/freezing process can be used for the treatment of Cr6+-contaminated wastewater.

2021-01-01T00:00:00Z Kim, Kitae Chung, Hyun Young Kim, Bomi Wong, Gracie Nguyen, Anh Quoc Khuong Kim, Saewung Kim, Jungwon https://repository.kopri.re.kr/handle/201206/11818 2022-03-24T07:14:51Z 2020-12-01T00:00:00Z

Title: Freezing-Induced Simultaneous Reduction of Chromate and Production of Molecular Iodine: Mechanism, Kinetics, and Practical Implications Authors: Kim, Kitae; Chung, Hyun Young; Kim, Bomi; Wong, Gracie; Nguyen, Anh Quoc Khuong; Kim, Saewung; Kim, Jungwon Abstract: A new method for the concurrent treatment of Cr(VI)-contaminated wastewater and production of the useful I2 chemical was developed. The method is based on the redox reaction between Cr(VI) and I？ that occurs when an aqueous wastewater solution containing Cr(VI) and I？ is frozen, producing I2 and allowing for the effective removal of Cr. The redox reaction occurs primarily due to the accumulation of Cr(VI), I？, and protons in the ice grain boundaries formed during freezing (i.e., the freeze concentration effect). This effect was verified by confocal Raman spectroscopy and the experiments varying I？ concentration and pH. The reduction of Cr(VI) (20 μM) was near complete after freezing at I？ concentrations ≥ 100 μM, pH ≤ 3.0, and temperatures ≤ ？10 °C. The freezing method (liquid cooling vs air cooling) had little effect on the final Cr(VI) reduction efficiency, but had a significant effect on the Cr(VI) reduction rate. The freezing method was also tested with Cr(VI)-contaminated electroplating wastewater samples and simultaneous Cr(VI) reduction and I2 production proceeded rapidly in a frozen solution but was not observed in an aqueous solution. Additionally, other substances in electroplating wastewater did not reduce the rate and final efficiency of Cr(VI) reduction and I2 production. Therefore, the freezing/Cr(VI)/I？ system can be considered a feasible approach to water-energy nexus technology for simultaneous I2 production and Cr(VI)-contaminated wastewater treatment.

2020-12-01T00:00:00Z