• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.18 no.2
• /
• pp.1-17
• /
• 2015

Ecological reservoir is a multifunctional space where provides the functions of retention, animal habitat and improvement of ecosystem health and landscape. The ecological reservoir of Anteo Eco Park located in Gwangmyeong-si has established to functions for water purification, maintenance of healthy aquatic ecosystem. Because the Anteo Eco Park is located in the site where nonpoint pollutant materials flow in, Anteo Eco Park has potential factors which aquatic ecosystem health deteriorates and damages the habitat of golden frog(Rana plancyi chosenica) which is restoration target species. Therefore, the purpose of this study is to suggest the plan to manage the variables which impede the right functions of aquatic ecosystem by understanding the causal loop diagram for the change of water quality environment and the interaction of predator-prey through system thinking. The results are as follows. First, the study showed that the individual number of golden frog which is an indicator species of Anteo Eco Park is threatened by snakeheaded fish, which is an upper predator. Therefore, balanced food chain should be hold to protect golden frog by capturing the snakeheaded fish which is individual number's density is high, and the monitoring management of the individual number for predator(snakeheaded fish)-prey(golden frog) should be performed. Second, the study represented that water pollution and carnification is caused by the sediment as the dead body of the large emergent vegetation in the winter cumulates as sediment. Ecological reservoir in Anteo Eco Park has been managed by eliminating the dead body of the large emergent vegetation, but the guideline for the proper density maintenance of vegetation community is additionally needed. Lastly, the study showed that aquatic ecosystem of Anteo Eco Park where is contaminated from the inflow of nonpoint pollutants affects the individual number's decline of golden frog and snakeheaded fish. Accordingly, the creation of a buffer area and a substitution wetland is needed in the periphery of the Anteo Eco Park to control the inflow of nonpoint pollutants including organic matters, nutrients and heavy metals. This study will be helpful that Anteo Eco Park improves the regional landscape and maintain healthy aquatic ecosystem space for the park visitors including local residents.

• Journal of the Korean Geosynthetics Society
• /
• v.14 no.4
• /
• pp.139-146
• /
• 2015

This paper describes a effect of nano-bubble on removal of complex heavy metals, in order to remove pollutants of soil with copper (Cu) and lead (Pb) based on column test. It was conducted column test considering inflow and fine soil contents condition, and then it was analyzed removal effect of nano-bubble on Cu and Cu/Pb. The test result showed that the removal effect of the nano-bubble was higher than that of distilled water regardless of fine soil contents in case of Cu pollutant, and the removal effect of nano-bubble on heavy metals was found to have a significant impact on Pb than Cu in case of Cu/Pb pollutants. It was also analyzed that engineering properties (like a flow path and permeability) of soil due to void ratio has influenced a significant impact the pollutants removal of nano-bubble. The test results determined that nano-bubble can be applied as a flushing agent for priority target pollutant in complex heavy metals.

• Journal of Wetlands Research
• /
• v.19 no.1
• /
• pp.37-44
• /
• 2017

Nonpoint source (NPS) pollution continues to degrade the water quality. NPS pollutants signals high concerns against a sustainable environment. Low impact development (LID) is the leading management practice which regulates and treats stormwater runoff especially in highly impervious urban areas. Constructed wetlands are known to have efficient removal capability of NPS pollutants. Likewise, these LID facilities were intended to maintain the predeveloped hydrologic regime through series of mechanisms such as particle settling, filtration, plant uptake, and etc. In this study, the objective was to investigate the characteristics, fate and treatment performance of the two in-campus constructed wetlands (SW1 and SW2) which were installed adjacent to impervious roads and parking lots to treat stormwater runoff. A total of 42 storm events were monitored starting from July 2010 until November 2015. Manual grab sampling was utilized at the inlet and outlet units of each LID facilities. Based on the results, the wetlands were found to be effective in reducing 37% and 41% of the total runoff volume and peak flows, respectively. Aside from this, outflow EMCs were generally lower than the inflow EMCs in most events suggesting that the two wetlands improved the water quality of stormwater runoff. The average removal efficiency of pollutants in facilities were 63~79% in TSS, 38~54% in TN, 54% in TP and 32%~81% in metals. The results of this study recommend the use of constructed wetlands as efficient treatment facility for urban areas for its satisfactory performance in runoff and pollutant reduction.

• Journal of Korea Water Resources Association
• /
• v.52 no.4
• /
• pp.265-277
• /
• 2019

The objective of this study was to develop and verify an effective vortex typed nonfilter nonpoint source pollution reduction device. To verify this pollution reduction device, a total of twelves scenarios (three rainfall intensities${\times}$two states${\times}$two steps) of experiments were conducted using pollutants. First, simulated inflow (rainfall intensity 2.5 mm/hr: $0.00152m^3/s$, rainfall intensity 3.395 mm/hr: $0.00206m^3/s$, rainfall intensity 6.870 mm/hr: $0.00326m^3/s$) was calculated. Second, pollutants (mixture of 25% of four particle sizes) were selected and injected. Third, pollutant removal efficiencies of this device at its initial state and operating states were measured. As a result of analysis based on rainfall intensity, the concentration of pollutants was decreased by the device at initial and operating states at all rainfall intensities. Its pollutant removal efficiency was more than 80%, the standard set by the Ministry of Environment. Its pollutant removal efficiency was gradually increased over time, reaching approximately 90%. Its pollutant removal efficiency was higher in its operating state than that in its initial state. Therefore, nonpoint source pollutants can be effectively removed by this vortex typed nonpoint source pollution reduction device developed in this study.

• Journal of Environmental Impact Assessment
• /
• v.31 no.1
• /
• pp.1-10
• /
• 2022

This study was carried out to understand the water quality characteristics of the initial stormwater runoff and the origin of soluble pollutants according to various rainfall conditions from a non-point source reducing facility. The water sample from this study was collected among 10 collection facilities in the G-drainage area. Specifically, five of the collection points including #1, #5, #8, #9, and #10 were reported with unknown water inflow even during non-rain conditions. The leakage characteristics of non-point pollutants from the collection facilities were then able to identify accordingly. The water quality characteristics of the stormwater runoff from the collection facilities were strongly affected by the amounts of rainfalls. The average concentrations of EC, BOD, TOC, and TN during non-rain were found to be higher than their concentrations during rain; on the other hand, the average concentrations of DO were found to be lower than its concentrations during rain. In addition, the distribution of organic components existing in the effluent of collection facilities were identified based on the dissolved organic matter analysis. In summary, the stormwater runoff was highly affected by pollutants flowing from the surrounding environment, and the amounts of hard-to-decompose humic substances were greatly increased in the collection facilities due to rain.

• Journal of Environmental Impact Assessment
• /
• v.21 no.3
• /
• pp.367-380
• /
• 2012

There are many long and round shape shores due to terrain characteristics in Daecheong reservoir. Therefore it is indicated different spatial distribution of algae every year since the stream is being regulated by these terrain characteristics and reservoir operation about inflow and outflow discharge. Also oversupply of nutrient salt from tributaries of Daecheong reservoir where pollutants were concentrated generates massive growth of algae and depending on hydrological, reservoir operation condition, those proliferated algae at the stagnant tributaries moves to the mainstream of Daecheong reservoir which could create problems of water quality. In this study, it was analyzed the tendency of algae generation by examining algae occurring status for the last 4 years since 2008, and implemented hydraulic analysis at Daecheong reservoir through numerical tracer simulation by applying 3-dimensional hydrodynamic model, ELCOM. Also it was implemented a quantitative analysis of causal relationship based on the algae generation tendency and hydraulic behavior at Daecheong reservoir. Through numerical tracer simulation in this study, it could be noticed the degree of spread of inflow indicated similar trend to the algae occurring status at Daecheong reservoir and verified the different tendency of algae generation in 2011 unlike previous year caused by the rise of water temperature.

• Journal of Korean Society on Water Environment
• /
• v.36 no.2
• /
• pp.116-124
• /
• 2020

This study aims to identify the characteristics of organic matter and pollutant sources using water quality and stable isotope ratios (δ¹⁵N, δ¹³C) of the two inflow tributaries (Gulpo (GP) and Anyang (AY) streams). Water samples were analyzed in June and September 2018, and the results showed that the concentrations of nutrients, such as TN and NO₃-N, were increased at GP4, which is located at the downstream of sewage treatment facilities(STFs). TOC and TN ratios showed a strong positive correlation (R² = 0.77, p<0.01) at all points except for GP4. The results of GP's stable isotope ratio analysis do not appear to be a constant cluster compared to AY because GPs with large amounts of pollutants from the industry (metal processing companies, etc.) have less tributary, shorter waterway and significantly different external sources. This could be attributed to different sources of external inflow despite its smaller number of tributaries and shorter waterways than AY. In the first half of the year, the δ¹⁵5N of GP4 was affected by discharge of STFs, while AY3 seemed to have an influence of tributary than the discharge of STFs. Consequently, using water quality, stable isotope ratio and C/N, the sources of contamination in two streams with different contaminants were identified and origin was estimated.

• Wind and Structures
• /
• v.24 no.1
• /
• pp.1-24
• /
• 2017

Wind environment in urban residential areas is an important index to consider when evaluating the living environment. However, due to the complexity of the flow field in residential areas, it is difficult to specify the correct inflow boundary conditions in the large eddy simulation (LES). In this paper, the weighted amplitude wave superposition (WAWS) is adopted to simulate the fluctuating velocity data, which satisfies the desired target wind field. The fluctuating velocity data are given to the inlet boundary of the LES by developing an UDF script, which is implemented into the FLUENT. Then, two numerical models - the empty numerical wind tunnel model and the numerical wind tunnel model with spires and roughness elements are established based on the wind tunnel experiment to verify the present method. Finally, the turbulence generation approach presented in this paper is used to carry out a numerical simulation on the wind environment in an urban residential area in Lisbon. The computational results are compared with the wind tunnel experimental data, showing that the numerical results in the LES have a good agreement with the experimental results, and the simulated flow field with the inlet fluctuations can generate a reasonable turbulent wind field. It also shows that strong wind velocities and turbulent kinetic energy occur at the passageways, which may affect the comfort of people in the residential neighborhood, and the small wind velocities and vortexes appear at the leeward corners of buildings, which may affect the spreading of the pollutants.

• 한국방재학회:학술대회논문집
• /
• 2008.02a
• /
• pp.795-798
• /
• 2008

An estuary is very important that the seawater and the freshwater meet and they formed wide foreshore and estuarine which is used as the habitat of various living thing and spawning bed of fish. Masan bay is typical closing bay in Korea. It is located 9 km from the open sea and most inside of Jinhae bay. The width of bay entrance is less than 1 km, where the flow velocity is very low. The large scale industrial complex of Masan bay is located in near Masan and Changwon city whose population is about 100 million. Because of low tidal velocity, the pollutants from the land are accumulated, which makes the water quality worse in Masan bay. The purpose of this study is to analyze the various hydraulic characteristics using RMA-2 model. The advection and diffusion of pollutant is also simulated using RMA-4 model according to the inflow of Changwon-stream and Nam-stream. The hydraulic simulations include the effect of tide which can be characterized by the tide data of Masan bay tide observatory.

• Korean Journal of Ecology and Environment
• /
• v.43 no.2
• /
• pp.263-270
• /
• 2010

This is a research on development of water purification equipment called artificial floating island (=AFI) for the stagnant water area which can secure exuberant landscape and water-friendility. The equipment devised in this study is designed to make up the weakness of conventional AFIs and improves the removal efficiency of pollutants using the mixture of media and plants. The air compressor positioned at the inlet releases air with inflow continuously, the water pump at the outlet sprays as a form of fountain with causing a disturbance on stable water column, then, both of them contribute improvement of water quality over a large area. We applied Bio-stone as a media in this system and performed an experiment of pre-efficiency test, and we concluded that the higher pollutants concentration of inflow, the higher removal efficiency we obtained. At the result of lab-scale experiment, in the case of high-concentration inflow, in the removal efficiency of SS is 62.2%, BOD is 50.2%, COD is 55.1%, T-N is 31.6%, T-P is 38.4%. In addition, to evaluate the field application, we set up the facilities in Sin-gal lake located in Yongin-Si Gyeonggi-Do, and researched on the removal efficiency of outflow relative to the inflow. As a result, SS is 53.5%, BOD is 32.8%, COD is 36.9%, T-N is 22.6%, T-N is 33.2%.