This study was conducted to investigate the effect of salt concentration and turbidity on the inactivation of Artemia sp. by electrolysis, UV photolysis, electrolysis+UV process to treat ballast water in the presence of brackish water or muddy water caused by rainfall. The inactivation at different salt concentrations (30 g/L and 3 g/L) and turbidity levels (0, 156, 779 NTU) was compared. A decrease in salt concentration reduced RNO (OH radical generation index) degradation and TRO (Total Residual Oxidant) production, indicating that a longer electrolysis time is required to achieve a 100% inactivation rate in electrolysis process. In the UV process, the higher turbidity results in lower UV transmittance and lower inactivation efficiency of Artemia sp. Higher the turbidity resulted in lower ultraviolet transmittance in the UV process and lower inactivation efficiency of Artemia sp. A UV exposure time of over 30 seconds was required for 100% inactivation. Factors affecting inactivation efficiency of Artemia sp. in low salt concentration are in the order: electrolysis+UV > electrolysis > UV process. In the case of electrolysis+UV process, TRO is lower than the electrolysis process, but RNO is more decomposed, indicating that the OH radical has a greater effect on the inactivation effect. In low salt concentrations and high turbidity conditions, factors affecting Artemia sp. inactivation were in the order electrolysis > electrolysis+UV > UV process. When the salt concentration is low and the turbidity is high, the electrolysis process is affected by the salt concentration and the UV process is affected by turbidity. Therefore, the synergy due to the combination of the electrolysis process and the UV process was small, and the inactivation was lower than that of the single electrolysis process only affected by the salt concentration.
Water quality is characterized by various complex factors. Therefore, a systematic understanding of water quality trends is required to carry out a proper evaluation. In this study, we analyzed the spatio-temporal water quality characteristics of the Nakdong River using five-year data from 2012 to 2016. Data was collected on the pH, DO, BOD, COD, SS, TN, TP, TOC, WT, EC, NH3-N, NO3-N, PO4-P, Chl-a, rainfall, and total and fecal coliforms. A total of 38 water quality measurement stations, from Andong1 to Gupo, were considered. Statistical analyses including trend, cluster, and factor analyses were conducted to identify the dominant water quality components affecting the Nakdong River. The Nakdong River was spatially classified into three groups for up-stream (Andong1 to Sangju1), mid/up-stream (Donam to Dalseong), and mid/down-stream (Hwawonnaru to Gupo) data collection, and temporally into two groups for summer/fall (7~10), and the rest of the season (11~6) data. The water quality of the entire Nakdong River showed trends similar to the mid/down-stream section, which indicates the importance of water quality management in this section. Suspended solids, phosphorus, and coliform groups were established as important factors to be considered in the summer/fall season across the river, especially in the mid/down-stream section. Nitrogen and organic matter were identified as important factors to be considered in the rest of the season, especially in the mid/up-stream section. This study could help determine the water quality components that should be intensively monitored in the Nakdong River.
This study aimed to analyze the growth and physical responsees of Dracaena braunii in response salt accumulation in ornamental water culture and to examine the effect of activated carbon on this growth response. The experiment was conducted in a plant growth chamber and the indoor environmental conditions of the chamber were set at 23 ± 1℃ temperature, 70 ± 3% humidity, and 1,000 lux brightness. The observation of the growth response of plants in the presence of activated carbon showed that the pH with activated carbon maintained sub-acidic to neutral (6.27∼7.32) conditions and showed decreased electric conductivity in the media. As the treatment with added activated carbon showed good growth and physical responses, this indicated that absorption effect of activated carbon had a positive influence on the growth of plants. However, as the absorption effect of activated carbon may decrease over time and the use of high concentrations of activated carbon might cause nutrition shortage, various concentration of activated carbon and their absorption effects need to be investigated in the future.
The National Institute of Environmental Research (3rd KONEHs) conducted a survey of 280 residents in Ulsan, Suwon and Asan, and the concentration of heavy metals in the blood and urine were also analyzed. In case of blood lead concentration, Ulsan 2.27 ㎍/㎗, Suwon 2.08 ㎍/㎗, and Asan 1.75 ㎍/㎗, the high peak in Ulsan, and the low peak in Asan. In case of cotinine concentration, Ulsan smoking(609.16 ㎍/g_ct) is higher than nonsmoking(74.07 ㎍/g_ct), as Suwon and Asan smoking(416.72 ㎍/g_ct, 903.21 ㎍/g_ct) is higher than nonsmoking(72.72 ㎍/g_ct, 18.06 ㎍/g_ct), smoking group is higher than nonsmoking group in all areas revealed statistically significant correlation(p<0.01). In considering results synthetically, these study results are an aid to constructing environmental health science-side heavy metal management measure education programs for normal residents.
In this study, the impacts of local meteorology caused by tidal changes in the West Sea on ozone distributions in the Seoul Metropolitan Area (SMA) were analyzed using a meteorological model (WRF) and an air quality (CMAQ) model. This study was carried out during the day (1200–1800 LST) between August 3 and 9, 2016. The total area of tidal flats along with the tidal changes was calculated to be approximately 912 km2, based on data provided by the Environmental Geographic Information Service (EGIS) and the Ministry of Oceans and Fisheries (MOF). Modeling was carried out based on three experiments, and the land cover of the tidal flats for each experiment was designed using the coastal wetlands, water bodies (i.e., high tide), and the barren or sparsely vegetated areas (i.e., low tide). The land cover parameters of the coastal wetlands used in this study were improved in the herbaceous wetland of the WRF using updated albedo, roughness length, and soil heat capacity. The results showed that the land cover variation during high tide caused a decrease in temperature (maximum 4.5℃) and planetary boundary layer (PBL) height (maximum 1200 m), and an increase in humidity (maximum 25%) and wind speed (maximum 1.5 ms-1). These meteorological changes increased the ozone concentration (about 5.0 ppb) in the coastal areas including the tidal flats. The increase in the ozone concentration during high tide may be caused by a weak diffusion to the upper layer due to a decrease in the PBL height. The changes in the meteorological variables and ozone concentration during low tide were lesser than those occurring during high tide. This study suggests that the meteorological variations caused by tidal changes have a meaningful effect on the ozone concentration in the SMA.
In this study, the water quality components (pH, BOD, COD, TOC, SS, DO, TP) and the water quality, observed for 10 years (2008~2017) in the five tributaries of the Nakdong River with the highest flow rates, were analyzed. Monthly levels of the water quality components were estimated and regression functions were used to quantitatively explain the changes in the BOD and COD components, with respect to the TOC components. The results of analyzing the water quality levels in terms of the living environmental standards show that the lowest water quality was observed midstream (ST-3) and the highest water quality was observed upstream (ST-1 and ST-2). The regression function was estimated to be a linear function in all five tributaries, and the goodness of fit of the function was high upstream (ST-2), midstream (ST-3), and downstream (ST-4). According to the regression analysis using the observation data from 2008~2017, we found that the consumption of dissolved oxygen increased with an increase in organic matter in the major tributaries of the Nakdong River.
The purpose of this study was to propose an efficient management plan for purchased land considering the hydrological, watershed characteristics and ecological functions of the target land and surrounding area based on the result of monitoring the water quality improvement effect obtained by purchasing the land in the watershed area in the Geum river system. For this purpose, this study investigated through literature review, and examined ways to apply them to this research by deriving implications from a comprehensive analysis of previous research cases. After that, the components of assessment were derived to evaluate the ecological function of the purchase land, and the ecological function evaluation model for each land and area was proposed. In order to select purchase and restoration priorities of the land, this study analyzed the ecological status of the purchased land in main watersheds and tributaries using Arc GIS ver 10.1. Through this, a process to select restoration priorities was developed. And this study constructed the integrated management process with proposing a mid - to long - term plan by integrating the purchased land valuation and restoration priority selection process. Based on this process, this study suggested an effective management plan for purchased land through the integrated ecological management system of lands purchased. It can be used systematically in appraisal valuation, land purchase system, restoration project, and follow-up management of land purchase.
This study investigated the relationship among seven species of trichoderma through the identification of strains collected in Korea. The phylogenetic tree among the collected strains was classified into four groups. The trichoderma strains isolated in this way showed inhibitory effect on the fusarium wilt which is parasitic to cotyledon stem..The invisibility of J9, J10, J13 and J16 strains were higher in comparison with other strains in vitro test stand, and their spore production level was also higher. In the aluminum ring tests, it showed that the yield of the spores in J9, J10 and J13 were more than any other strain. As a result conducting the port test for cucumbers, the plant lengths of J13 were larger than the control plot, and the root lengths of all strains, except for J2 were longer than the control plot, and the root weights of J1, J9, J10, J13 and J16 were larger than the control plot. The disease severity for the fusarium wilt showed the smallest values at J13 and J16 in comparison with the control plot, and the control values of J13 and J16 were higher than other strains.