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Water treatment plants (WTPs) that intake raw water from the Paldang Dam of the Han River have generally adopted ozone + granular activated carbon (GAC) processes for the effective removal of taste and odor substances. In recent years, the concentration and duration of the substances causing taste and odor in Paldang Lake have gradually increased. Therefore, it is necessary to review the appropriateness of the advanced water treatment processes introduced in the WTPs located in the Han River. This study attempted to compare and review two processes for geosmin removal, one using a pre-ozone GAC filter-adsorber (pre-ozone + F/A) at the B WTP and the other using a post-ozone GAC adsorber (post-ozone + GAC) at the G WTP. The results of the investigation for geosmin and 2-MIB concentrations upstream of the Paldang Dam over the past 5 years showed that 2-MIB exceeded the standard concentration for less than 5 d per year and geosmin was the main cause of taste and odor. At the B WTP in the winter of 2011, the total geosmin concentration in the treated water exceeded 20 ng/L twice. Additionally, the average total geosmin concentration of the treated water after the application of the F/A was 7.81 ng/L. On the other hand, in the case of the G WTP, the total geosmin concentration after post-ozone and GAC treatment was 0.45 ng/L. In the summer of 2012, the fraction of particulate geosmin (66.9%-82.3%) was higher than that of dissolved geosmin (17.7%-33.1%) in the raw water of the two WTPs. During this period, the average removal rates of total geosmin in the final treated water of the G WTP were 0.7% higher than that of the B WTP. Therefore, ozone injection into filtered water after removing particulate geosmin and organic substances through the standard treatment process (coagulation, sedimentation, and filtration) is thought to be effective for removal to lower the concentration of dissolved organic matter and dissolved geosmin. In conclusion, the treatment efficiency was confirmed to vary according to the stage at which the process was used, even when the same ozone + activated carbon adsorption process was used. In addition, the 'post-ozone + GAC' method is considered advantageous when introducing advanced WTPs in the Han River. [ABSTRACT FROM AUTHOR]

Background End-stage renal disease is a common predisposing condition for the development of hypoglycaemia. Aim To determine the effect of hypoglycaemia on the mortality of patients undergoing maintenance dialysis. Methods Retrospective and descriptive analyses were performed in five dialysis centres in the Republic of Korea between June 2002 and August 2008. We enrolled 1685 patients who had undergone dialysis for at least 1 month. Results We identified 453 episodes of hypoglycaemia in 256 of 1685 patients (15.2%); 189 patients (73.8%) had diabetes, whereas the other patients did not. The occurrence of hypoglycaemia in patients receiving dialysis appeared to be a life-threatening complication because 27.0% of patients died within two days of the onset of a hypoglycaemic episode. Older age, low serum albumin levels and infections were independent risk factors for total mortality in these patients. Furthermore, the absence of diabetes, age and serum glucose levels were independent factors associated with early mortality within two days of the development of hypoglycaemia. Conclusion Although several factors were associated with mortality, the degree of hypoglycaemia, absence of diabetes and old age were associated with early mortality. Elderly hypoglycaemic patients, especially those without diabetes, should be closely monitored. [ABSTRACT FROM AUTHOR]

Studies effect of oral tamoxifen on growth and survival in the bagrid catfish, Pseudobagrus fulvidraco. Health benefits of tamoxifen; Rearing of bagrid catfish in South Korea; Effect of different concentrations of dietary tamoxifen on survival of bagrid catfish.

This investigation examines aerosol dynamics during major fine mode aerosol transboundary pollution events in South Korea primarily during the KORUS-AQ campaign from May 1 – June 10, 2016, particularly when cloud fraction was high and/or fog was present to quantify the change in aerosol characteristics due to near-cloud or fog interaction. We analyze the new AERONET Version 3 data that have significant changes to cloud screening algorithms, allowing many more fine-mode observations in the near vicinity of clouds or fog. Case studies for detailed investigation include May 25–26, 2016 when cloud fraction was high over much of the peninsula, associated with a weak frontal passage and advection of pollution from China. These cloud-influenced Chinese transport dates also had the highest aerosol optical depth (AOD), surface PM 2.5 concentrations and fine mode particle sizes of the entire campaign. Another likewise cloud/high relative humidity (RH) case is June 9 and 10, 2016 when fog was present over the Yellow Sea that appears to have affected aerosol properties well downwind over the Korean peninsula. In comparison we also investigated aerosol properties on air stagnation days with very low cloud cover and relatively low RH (May 17 & 18, 2016), when local Korean emissions dominated. Aerosol volume size distributions show marked differences between the transport days (with high RH and cloud influences) and the local pollution stagnation days, with total column-integrated particle fine mode volume being an order of magnitude greater on the pollution transport dates. The PM 2.5 over central Seoul were significantly greater than for coastal sites on the transboundary transport days yet not on stagnation days, suggesting additional particle formation from gaseous urban emissions in cloud/fog droplets and/or in the high RH humidified aerosol environment. Many days had KORUS-AQ research aircraft flights that provided observations of aerosol absorption, particle chemistry and vertical profiles of extinction. AERONET retrievals and aircraft in situ measurements both showed high single scattering albedo (weak absorption) on the cloudy or cloud influenced days, plus aircraft profile in situ measurements showed large AOD enhancements (versus dried aerosol) at ambient relative humidity (RH) on the pollution transport days, consistent with the significantly larger fine mode particle radii and weak absorption. • Highest AOD and PM 2.5 over S. Korea had significant cloud cover and/or sea fog. • Particle volume was at least 10 times larger on high RH pollution transport days. • Particle SSA was high (0.97–0.99 in mid-visible) on pollution transport days. • The PM 2.5 was higher over central Seoul than the coast during pollution transport. [ABSTRACT FROM AUTHOR]