https://pubs.kist.re.kr/handle/123456789/75376 2026-04-15T18:24:48Z https://pubs.kist.re.kr/handle/201004/150831 Title: Ensemble process for producing high-purity H2 via simultaneous in situ H2 extraction and CO2 capture Authors: Jin, Seongmin; Park, Yongha; Jo, Young Suk; Lee, Chang-Ha Abstract: To produce fuel-cell-grade hydrogen (H-2) via fossil fuel reforming processes, an efficient H-2 purification method with a carbon capture unit is necessary. In this study, a sorption-enhanced water-gas shift membrane reactor (SE-WGS-MR) system combining a state-of-the-art MgO-based catalyst, carbon dioxide sorbent, and Pd/Ta membrane is developed to simultaneously capture carbon dioxide and purify H-2. With the optimal sorption-enhanced configuration (SEWGS), the carbon monoxide conversion is significantly enhanced to 86.6%, compared with 68.5% using the commercial catalyst only. Coupling of the Pd/Ta membrane with the WGS catalyst (WGS-MR) enable over 95% H-2 recovery, with the production of high-purity H-2. Eventually, the ensemble of the three processes (SE-WGS-MR) afford 99.99% of carbon monoxide conversion and the extraction of high-purity H-2 with 99.5% recovery. This study demonstrates the potential of the single process integrating the catalytic reaction, adsorptive separation, and membrane purification for the production of H-2 with ultra-high purity and recovery. 2022-08-01T00:00:00Z https://pubs.kist.re.kr/handle/201004/115925 Title: Quantitative Hg2+ detection via forming three coordination complexes using a lysosome targeting quinoline - Fisher aldehyde fluorophore Authors: Muthusamy, Selvaraj; Zhao, Long; Rajalakshmi, Kanagaraj; Zhu, Dongwei; Wang, Shengjun; Mack, John; Lee, Kang-Bong; Zhang, Long; Zhu, Weihua Abstract: This work describes (Z)-N-((Z)-2-(1,3,3-trimethylindolin-2ylidene)ethylidene)quinoline-8-amine (LYSO-QF), a high-performing and biocompatible dye comprised of quinoline and Fisher aldehyde moieties linked via an imine vinyl backbone with lysosome targeting ability that can be used to quantitatively detect the mercury ion (Hg2+) in biosystems and the natural environment. This is achieved by forming three different tetrameric, trimeric and dimeric complexes between Hg2+ and LYSO-QF with the limit of detection (LOD) of 11 nm. The complexes formed were analyzed with the aid of time-dependent density functional theory (TD-DFT) calculations. The concentration dependence of the Hg2+ complex fluorescence emission changes from grey-green to jade green and then to red as the different types of complex are formed. The favorable sensor properties of the LYSO-QF probe are demonstrated by monitoring different Hg2+ concentrations in buffer solutions, HeLa cells, zebrafish model samples and several different types of water sample. Experiments with Whatman paper strips demonstrate that the cost-effective LYSO-QF also has considerable potential for use in on-site Hg2+ detection with the naked eye. 2022-01-01T00:00:00Z https://pubs.kist.re.kr/handle/201004/115924 Title: Long-term monitoring and risk assessment of N-nitrosamines in the finished water of drinking water treatment plants in South Korea Authors: Hashemi, Shervin; Park, Ju-Hyun; Yang, Mihee; Kim, Joeun; Oh, Yunsuk; Pyo, Hee soo; Yang, Jiyeon Abstract: Approximately 99.1% of South Koreans have access to drinkable tap water from river basins. Due to such a high access rate, the South Korean government has been running, since 2013, a long-term program for monitoring the quality of tap water for drinking. Under this program, the maximum allowed concentrations of N-nitroso-di-n-methylamine (NDMA) and N-nitrosomethylethylamine (NMEA) are defined and applied. In this study, the data from this monitoring program were used to investigate the changes in six N-nitrosamine substances in the finished water of 33 drinking water treatment plants (DWTPs) in South Korea from 2013 to 2020, based on time and location. The effect of the applied water treatment steps on the appearance of N-nitrosamines was analyzed. The excess cancer risk (ECR) due to the oral intake of these substances was assessed. The results before the maximum allowed concentrations of NDMA and NMEA were defined showed that the oral intake ECR of these substances exceeded the carcinogenesis risk of one per one million people per year. After the maximum allowed concentrations of the substances were applied, the concentrations of the substances in the finished water of the DWTPs significantly dropped. The drinking water treated through sand filtration, and then with granular activated carbon, showed the highest efficiency in preventing the appearance of NDMA. Considering the potency of N-nitrosamines in tap water for drinking, the levels of these substances in the finished water of DWTPs in South Korea should be continuously monitored. 2022-01-01T00:00:00Z https://pubs.kist.re.kr/handle/201004/115923 Title: Transient behavior of arsenic in vadose zone under alternating wet and dry conditions: A comparative soil column study Authors: Tho Huu Huynh Tran; Kim, Sang Hyun; Jo, Ho Young; Chung, Jaeshik; Lee, Seunghak Abstract: The water and oxygen contents of the vadose zone change cyclically depending upon the meteorological condition (e.g., intermittent rainfall), which can affect the biogeochemical reactions that govern the fate of arsenic (As). To simulate and evaluate the transient behavior of As in this zone when subjected to repeated wet and dry conditions, soil column experiments with different soil properties were conducted. Three wetting-drying cycles resulted in the fluctuation of water and dissolved oxygen contents, and consequently, the reduction-oxidation potential in the soil columns. Under these circumstances, the biotic reduction of As(V) to As(III) was observed, especially in the column filled with soils enriched in organic matter. Most of the As was found to be associated with soil particles rather than to be dissolved in the pore water in all of the columns tested. Retention of As was more preferable in the soil column with a higher Fe content and bulk density, which provided more sorption sites and reaction time, respectively. However, a considerable amount of soil-bound As could be remobilized and released back to the pore water with the repetition of wetting and drying due to the transformation of As(V) to As (III). 2022-01-01T00:00:00Z