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2019, Vol.28, No.6

  • 1.

    Simulations of the Effect of Flow Control and Phosphate Loading on the Reduction of Algae Biomassin Gangjeong-Goryong Weir

    park dae yeon | sungjin kim | Park, Hyung Seok and 1other persons | 2019, 28(6) | pp.507~524 | number of Cited : 0
    Abstract PDF
    The purpose of this study was to validate the EFDC model forthe weir pool of GangjeongGoryong Weir located in NakdongRiver, and evaluate the effect offlow control and phosphate loading reduction on the water quality and algae biomass by group (Diatom, Green, Cyanobacteria). As a result of model validation using 2018 experimental data,the time series of waterlevel and vertical distribution of water temperature, DO, organic matter, nitrogen, and phosphorus time series were properly simulated. Seasonal fluctuations of algae biomass by group were adequately reproduced, but the deviations between measured and simulated values were significant in some periods. As a result of scenario simulations to control the waterlevel and flow rate, the thermal stratification was resolved as the water level was lowered and the flow rate increased. The flow velocity at which the water temperature stratification was resolved was about 0.1 m/s, which is consistent with the previous study results of BaekjeWeirin Geum River. Simulations ofthe 2Q flow scenario showed that Chl-a decreased by 8.7% and the cell density of diatom and green algae declined. The cell density of cyanobacteria increased, however, because the high concentrations of cyanobacteria in the upstream boundary conditions directly affected downstream due to increased flow velocity. In the scenario simulation of reducing the influent phosphate load concentration (average 0.056 mg/L) to 50%, Chl-a decreased by 13.6%.The results suggestthatthe upstream algae concentration and phosphorus load reduction should be considered simultaneously with hydraulic control to prevent algal overgrowth of GangjeongGoryong Weir.
  • 2.

    Evaluation of Wildlife Crossings Eeffectiveness on Use Frequency and Diversity Indicators of Wildlife

    Woo Donggul | Seo, Hyun-Jin | 박태진 and 3other persons | 2019, 28(6) | pp.525~535 | number of Cited : 0
    Abstract PDF
    In this study, 49 major WCS(Wildlife Crossing Structure), including Baekdu-daegan, were evaluated for the effectiveness of WCS on using the daily average frequency index and diversity Index comparing the number of species that appear with the surrounding habitats. According to the analysis, the average use frequency of the entire WCS was 1.4 times, and the average number of WCS exceeded the average was 17 and 34.7 percent of the total. There were 18 WCS with the same number of habitats and species that appeared in the same area, or 36.7 percent of the total. The daily average use frequency and variety were all analyzed at 10 efficient WCS, accounting for 20.4 percent of the total. According to the results of an site survey on the compliance rate of 4 efficient WCS, the compliance rate of the Deoksanjae overpass was the best in location selection, specifications, vegetation cover and soil, fence. The results of this research will be used as basic data for the study of WCS effectiveness, including the improvement of functions of new and installed WCS.
  • 3.

    Analysis of the Implementation Effect of Total Water Load Management System Using Load Duration Curvesin Sapgyo Watershed

    Lee Eun Jeong | Kim Tae Geun | 2019, 28(6) | pp.536~548 | number of Cited : 0
    Abstract PDF
    In orderto quantify the effect of the newly established the Total Water Load Management System in Sapgyo watershed, this study predicted the achievement of the target water quality at each unit watershed and the water quality according to the flow section. The HSPF model, which is the watershed runoff model, was constructed and operated based on 2015, and the water quality was predicted by inputting the loads in finaltarget year(2030). The Load Duration Curve (LDC) was created using the simulated results of base year and target year. As a result of plotting water quality by flow conditions, it was simulated to be close to the BOD target with a difference of 0.1 ~ 0.2 mg/L in allthree watersheds during the mid-range flow interval (40 ~ 60%). In case of T-P, although the target water quality was not set, the water quality was improved by Cheonan A 46%, Kokgyo A 29% and Namwon A 25%. The Muhan and Sapgyo river basins meetthe target grade of middle-watershed standards. The improvement effect will be positive, as water quality, which achieves the target of Total Load Management System and the target grade of the middle-watershed standards will be expected to flow into the Sapgyo lake.
  • 4.

    A Study on the Optimal Operating Conditionsfor Removal of Nutrient Influential Substances Using Functional Media

    Lee Jong Jun | oh Jong-Min | 최승종 and 1other persons | 2019, 28(6) | pp.549~555 | number of Cited : 0
    Abstract PDF
    The purpose of this study is to ensure optimal operating conditions for improving the removal efficiency of phosphorus (P) and nitrogen (N) that are the causative agents of eutrophication by utilizing functional media. The main ingredients of the functional media used in this study are Si, Al, and Fe, SiO2, KAlSiO3O8, Al2O3 ·2SiO2O, H3Al2Si2O9, Fe3O4O), and berylite. To identify the maximum efficiency of the filtration process, the processing efficiency experiment was carried out according to flow method, velocity, and thickness of residual media. The flow method carried out two experiments, 50 m/day, 100 m/day, 150 m/day, 200 m/day, 250 m/day, and 20 cm, 40 cm, 50 cm, 60 cm, 80 cm of lead depth. Experiments have shown that SS, T-N, and T-P all showed higher elimination efficiency of the upflow current conditions than the downflow current conditions, and that the processing efficiency of the linearity is the highest at SS 50 m/day, T-N 150 m/day and T-P 100 m/day. In addition, the analysis of the removal efficiency according to the residual thickness showed that SS, T-N, and T-P all showed the highest efficiency at 60 cm. In addition, the analysis of the removal efficiency according to the residual thickness showed that SS, T-N, and T-P all showed the highest efficiency at 60 cm. It is considered desirable to set the top-down flow conditions and residual thickness of 60 cm and adjust the velocity of the line according to the target media for removal.
  • 5.

    A Study on the Performance Evaluation Index of Multi-Water Resources Connection and Continuous Utilization in Micro Water Grid

    Chae,Soo-Kwon | Lee Sang-Hoon | Ahn Hong-Kyu | 2019, 28(6) | pp.556~567 | number of Cited : 0
    Abstract PDF
    As the number of skyscrapers in micro water grid units such as green building and smart building is increasing in the world, the green building certification system is being implemented to solve problems such as increased demand for water resources and energy. However, researches on the use of sustainable water resources like water reuse and water conservation through linkage and continuous use of waterresources, while the power and energy sectors are actively conducting R&D projects in the green building certification system on the micro water grid level. Therefore, this paper analyzes the characteristics and limitations of the waterresources sectorforthe continuous utilization of multiple water sources in the green building certification system, due to the inadequate consideration of sustainability. Then investigates whether various waterresources such as constants, nature, and alternative water resources are continuously used in and out of the green building or smart building and complex in the micro water grid unit to suggest evaluation methods and performance evaluation standards.
  • 6.

    An Analysis of the Correlation between Seoul’s Monthly Particulate Matter Concentrations and Surrounding Land Cover Categories

    최태영 | 강다인 | Jae-Gyu Cha | 2019, 28(6) | pp.568~579 | number of Cited : 1
    Abstract PDF
    The present study aims to identify the effect of land cover categories on particulate matter (PM) concentrations by analyzing the correlation between monthly PM concentrations in Seoul’s air quality monitoring network and the percentages of land cover categories by buffers around air quality monitoring stations. According to a monthly correlation analysis between land cover categories and PM concentrations, in the buffer 3km, PM10 showed a better correlation than PM2.5, there was a clear negative correlation with the forest area, the grassland and the urbanized area had some positive correlation with PM10, and the barren land and the urbanized area had some positive correlation with PM2.5. According to a monthly correlation analysis of dominant land cover sub￾categories and sub-sub-categories within the buffer 3km, PM10 showed a clear negative correlation with the broad-leaved forest, and some positive correlation with the road was dominant. PM2.5 showed partly negative correlation with the broad-leaved forest and partly positive correlation with the commercial area. There was a very low or no correlation with other grassland and bare land sub￾categories. A monthly stepwise regression analysis on noticeable land cover sub-categories and sub￾sub-categories with positive or negative correlations revealed that an increasing percentage of the broad-leaved forest had a clear effect on reducing PM10 concentrations, and the road was excluded from the selected variables. Although an increasing percentage of the commercial area had some effect on increasing monthly PM2.5 concentrations and an increasing percentage of the broad-leaved forest had an effect on decreasing the PM2.5 concentrations, their effect size was smaller than that on PM10. The forest area around the city center had the largest and clearest effect on reducing PM concentrations. The urbanized area’s sub-categories and sub-sub-categories were also confirmed to have some effect on increasing PM concentrations.
  • 7.

    Analysis of Roadkill Hotspot According to the Spatial Clustering Methods

    Eui‑Geun Song | Seo, Hyun-Jin | Kyungmin Kim and 3other persons | 2019, 28(6) | pp.580~591 | number of Cited : 0
    Abstract PDF
    This study analyzed roadkill hotspots in Yeongju, Mungyeong-si Andong-si and Cheongsong-gun to compare the method of searching the area of the spatial cluster for selecting the roadkill hotspots. The local spatial autocorrelation index Getis-Ord Gi* statistics were calculated by different units of analysis, drawing hotspot areas of 9% from 300 m and 14% from 1 km on the basis of the total road area. The rating of Z-score in the 1km hotspot area showed the highest Z-score in the 28th National Road section on the border between Yecheon-gun and Yeongj-si. The kernel density method performed general kernel density estimation and network kernel density estimation analysis, both of which made it easier to visualize roadkill hotspots than district unit analysis, but there were limitations that it was difficult to determine statistically significant priority. As a result, local hotspot areas were found to be different according to the cluster analysis method, and areas that are in common need of reduction measures were found to be the hotspot of 28th National Road through Yeongju-si and Yecheon-gun. It is deemed that the results of this study can be used as basic data when identifying roadkill hotspots and establishing measures to reduce roadkill.
  • 8.

    Study on the Low Energy Sewage Management Based on Pre-sensing Technology and Automatic Blower Control

    이승명 | Han-lae Kim | 기경서 | 2019, 28(6) | pp.592~603 | number of Cited : 0
    Abstract PDF
    This study is about the implementation of low energy sewage management technology through effective control of blower which consumes the most energy in sewage treatment. In calculating the amount of oxygen required for microorganisms, unlike the existing method using the operating index in the bioreactor or TMS data in the discharge port, the CODcr and NH4+-N concentration changes in sewage flowing into the sewage treatment plant were detected in advance before entering the bioreactor and the amount of air was controlled based on this. The pre-sensing was found to have a high correlation compared with conventional products. As a result of blower control, it was possible to save about 9.9% energy more than the manual control. Consequently, this study suggested the possibility of blower’s real-time control combined with pre-sensing technology. Also, it is expected that the low energy sewage treatment can be applied to sewage treatment facilities dependent on operation by manpower, and it will contribute to the reduction of greenhouse gas emissions.
  • 9.

    Nutritional Properties by Composting Process of Algae Biomass as Soil Conditioner

    Chang Hyuk Ahn | Lee, Saeromi | Jaeroh Park | 2019, 28(6) | pp.604~615 | number of Cited : 0
    Abstract PDF
    In this study, we produce a new type of the algae soil conditioner(ASC) using discarded algae biomass through a composting process and evaluate its nutritional characteristics. As the main ingredient, the ASCs used algae biomass collected through the coagulation-floating method and made by adding a variety of additional supporting materials (sawdust, pearlite, oilcake etc.). ASCs were divided into 0% in blank, 11.7% in ASC1, 21.6% in ASC2, 37.6% in ASC3, 59.5% in ASC4, and composted during 127 days. ASCs showed a sharp increase in temperature by aerobic microbial reaction, and 6~7 high and low temperature peaks were observed. As a result of physicochemical analysis, mineralization proceeded according to decomposing the organic matter and there was a marked increase not only in macronutrients (TN, P2O5, K2O), but also in secondary macronutrients (CaO, MgO). The microbial community change was found in stage 1 (bacteria, filamentous fungi) → stage 2 (actinomycetes, bacteria) → stage 3 (Bacillus sp.), depending on the maturation process. It was estimated that microbial transition was closely related to temperature change and nutritional behavior. The quality of soil conditioner can be determined according to the maturity of compost process, and it was determined that effective microbial activity could be induced by controlling algae biomass below 59.5% in this study. In conclusion, we found out the possibility of manufacturing and utilizing soil conditioner recycled algae biomass and if further technological development is made on the basis it can be used as an effective soil conditioner.
  • 10.

    A Case Study on Health Impact Assessment of Hazardous Air Pollutants in Industrial Complex Development Plan

    김상목 | 손은성 | Young-Kyo Seo and 1other persons | 2019, 28(6) | pp.616~625 | number of Cited : 1
    Abstract PDF
    Health impact assessment is implemented within the Environmental impact assessment for the purpose of minimizing health damage by predicting the impact on human health following implementation of the development project. In health impact assessment, manualrevision is required due to the lack of consistency in the method of estimating hazardous air pollutants emissions. This study estimated the emissions by calculating the emissions of hazardous air pollutants based on the actual industrial complex development cases and completed health impact assessments. As a result of risk assessment based on exposure concentration using CALPUFF model, the risk assessment results were different for each of the emission estimation methods, and manual improvement on the emission estimation method is needed.