• Title/Summary/Keyword: ecosystem stabilization

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Evaluating Heavy Metal Stabilization Efficiency of Chemical Amendment in Agricultural Field: Field Experiment (안정화제 처리에 따른 중금속 오염 농경지 복원의 효율성 평가: 현장실증시험)

  • Oh, Se-Jin;Kim, Sung-Chul;Yoon, Hyun-Soo;Kim, Ha-Na;Kim, Tae-Hwan;Yeon, Kyu-Hun;Lee, Jin-Soo;Hong, Sung-Jo;Yang, Jae-E.
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.6
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    • pp.1052-1062
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    • 2011
  • Residual of heavy metals originated from abandoned metal mines in agricultural field can cause adverse effect on ecosystem and eventually on human health. For this reason, remediation of heavy metal contaminated agriculture field is a critical issue. In this study, five different amendments, agriculture lime, dolomite, steel slag, zeolite, and compost, were evaluated for stabilization efficiency of heavy metals in agricultural field. Applied mixing ratio of amendments was varied (2% or 6%) depending on properties of amendments. Result showed that soil pH was increased compared to control (6.1-6.7) after mixing with amendments and ordered as dolomite (7.2~8.3) > steel slag (6.7~8.1) > agriculture lime (6.6~7.4) > zeolite (6.2~6.9) > compost (6.1~7.1). Among other amendments, agriculture lime, steel slag, and dolomite showed the highest stabilization efficiency of heavy metals in soil. For Cd, stabilization efficiency was 49~72%, 51~83%, and 0~36% for agriculture lime, steel slag, and dolomite respectively. In case of Pb, 43~64, 37~73%, and 51~73% of stabilization efficiency was observed for agriculture lime, steel slag, and dolomite respectively. However, minimal effect of heavy metal stabilization was observed for zeolite and compost. Based on result of this study, amendments that can increase the soil pH were the most efficient to stabilize heavy metal residuals and can be adapted for remediation purpose in agricultural field.

Effects of Submerged Spur Dikes on the Ecosystem and Bed Deformation in Youngcheon River Bend (영천강 만곡부의 저수수제군이 생태계 및 하상변동에 미치는 효과)

  • Kim, Ki Heung;Lee, Hyeong-Rae;Jung, Hea Reyn
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.2
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    • pp.137-153
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    • 2013
  • In order to assess the effects of ecosystem and landscape in around spur dikes, this study had carried out monitoring on the changes of ecosystem and morphologic characteristics in around spur dikes that had been settled in bend of Youngcheon River. The study site was a short reach with length 190m, spur dikes were installed in March, 2008. Monitoring of the site had been started in May 2008 and had been completed September 2011. The results are as follow ; 1) Spur dikes that were installed for channel stabilization are performing effectively hydraulic functions at flooding time. 2) Spur dikes that were installed in water colliding front of river bend brought about sediment deposition between those and formed pools around front of those. Therefore, it was verified to create various physical characteristics in the aspect of channel topography and flow consequently. 3) The survey results that was carried out in October 2008 showed to emerge 25 species of plant, 9 species of fish and 17 species of benthic macroinvertebrates, but the survey results in October 2010 showed to emerge 74 species of plant, 12 species of fish and 19 species of benthic macroinvertebrates. In particular, plant species that emerged in 2011 increased about three times more than those in 2008.

Marine ecosystem risk assessment using a land-based marine closed mesocosm: Proposal of objective impact assessment tool (육상 기반 해양 폐쇄형 인공생태계를 활용한 해양생태계 위해성 평가: 객관적인 영향 평가 tool 제시)

  • Yoon, Sung-Jin
    • Korean Journal of Environmental Biology
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    • v.39 no.1
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    • pp.88-99
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    • 2021
  • In this study, a land-based marine closed mesocosm (LMCM) experiment was performed to objectively assess the initial stability of an artificial ecosystem experiment against biological and non-biological factors when evaluating ecosystem risk assessment. Changes in the CV (coefficient of value) amplitude were used as data to analyze the stability of the experimental system. The CV of the experimental variables in the LMCM groups (200, 400, 600, and 1,000 L) was maintained within the range of 20-30% for the abiotic variables in this study. However, the difference in CV amplitude in biological factors such as chlorophyll-a, phytoplankton, and zooplankton was high in the 600 L and 1,000 L LMCM groups. This result was interpreted as occurring due to the lack of control over biological variables at the beginning of the experiment. In addition, according to the ANOVA results, significant differences were found in biological contents such as COD (chemical oxygen demand), chlorophyll-a, phosphate, and zooplankton in the CV values between the LMCM groups(p<0.05). In this study, the stabilization of biological variables was necessary to to control and maintain the rate of changes in initial biological variables except for controllable water quality and nutrients. However, given the complexity of the eco-physiological activities of large-scale LMCMs and organisms in the experimental group, it was difficult to do. In conclusion, artificial ecosystem experiments as a scientific tool can distinguish biological and non-biological factors and compare and analyze clear endpoints. Therefore, it is deemed necessary to establish research objectives, select content that can maintain stability, and introduce standardized analysis techniques that can objectively interpret the experimental results.

Reduction Effect for Deposition in Navigation Channel with Vegetation Model (식생모형에 의한 항로매몰 저감 특성)

  • Lee, Seong-Dae;Kim, Seong-Deuk;Kim, Ick-Hyun
    • Journal of Navigation and Port Research
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    • v.36 no.8
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    • pp.659-664
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    • 2012
  • Coastal vegetaion consists of rooted flowering marine plants that provide a variety of ecosystem services to the coastal areas they colonize. The attenuation of waves and sediments stabilization are often listed among these services. From this point of view, artificial vegetation model is an effective method of controlling sea bed and stabilization without damaging the landscape or the stability of the coastaline. In this study, numerical and hydraulic physical test for predicting deposition proces of a navigation channel caused by wave action is proposed. In the numerical model, we develop a numerical model for describing the wave attenuation and sediment transport in a navigation channel with a vegetation area. In addition, hydraulic model tests is performed in a navigation channel with irregular waves to examine the effect of vegetation in relation to deposition reduction in navigation channel. A comparison between the results of hydraulic and numerical tests shows resonable agreement.

Effect on Nutrients Removal of Algae in Aerobic High Rate Pond by Irradiance Period and pH (호기성 고율 안정조에서 빛의 조사 기간과 pH가 조류의 영양물질 제거에 미치는 영향)

  • 공석기;안승구
    • Journal of Environmental Science International
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    • v.6 no.2
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    • pp.141-152
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    • 1997
  • The pilot plant had been made so as to be an association system from the various items managed to have degrees of efficiency and It have been done to consider the experimental result with irradiance period and pH influence of all major things to treatment function of Waste Stabilization Pond. The results are as following. The attained results for continuous & cyclic irradiance 1. 24L.-reactor was prior to 12L.-12D.-reactor on oxygen generation & algal production ability. 2. 24L.-reactor was prior to 12L.-12D.-reactor on nutrients removal efficiency. 3. In 24L.-reactor it maintained 5mg/L∼6mg/L, DO concent enough to a fish's survival. The attained results for pH condition 1. Oxygen generation ^ algal production in pH 4-reactor were higher than those in pH 10-reactor. 2. The acidic condition at pH 4 and alkalic condition at pH 10 did not so much affect an algal growth and nutrients removal. The attained results for whole 1. In view of the results appeared as [(NH3-N)+(NO3-N)] removal efficiency, 89.1%∼93.9% and PO4-P removal efficiency, 34.3%∼83.7% & COD removal efficiency, 88.5%∼93.9%. It is possible to treat the wastewater with starch and pH which have been known as thedifficult problem. 2. At the point of non using methanol to nitrificate NO3-N, the nutrients removal method by using an algal growth is the most economical method in the whole nutrients removal methods. 3. The nutrients removal method by using an algal growth contributes to natural ecosystem. 4. The nutrients removal method by using an algal growth is excellant in the prevention against the eutrophication.

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Analysis of Hydrodynamic Characteristics Apply to Nature-Friendly Stream Protection Method (자연형 호안공법을 적용한 소하천의 수리특성 분석)

  • Lee, Gang-Seuk;Park, Jong-Hwa;Yeon, Kyu-Bang
    • KCID journal
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    • v.17 no.2
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    • pp.71-81
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    • 2010
  • Stream Pilot Project, which began in May 2003 and finished in December 2003, was selected to develop effective methods applicable to nature-like streams. Stream restoration projects aim to maintain or increase ecosystem goods and services while protecting downstream and coastal ecosystems. Fields environmental monitoring such as flow discharge and precipitation were conducted along the Idong stream for amount of channel zone change in 2007. This study selected three monitoring positions to measure the water level and discharge of flowing water. A stage-discharge relation is obtained from direct discharge measurements for three stations by fitting an empirical relationship to the data set. Since discharge measures are made only for low flow conditions, a curve of discharge against stage can then be built by fitting these data with a power curve. And this study used data obtained from floodmark checkup as well as HEC-RAS model to analyze the hydrodynamic characteristics of monitoring sites. Reach-averaged hydraulic parameters for the supply reach were calculated from the small area's HEC-RAS model for Idong stream, and a HEC-RAS model used to analyze hydraulics for a period in 2007, after the stream was considered bank stabilization.

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Analysis on the Type of Damaged Land in DeMilitarized Zone(DMZ) Area and Restoration Direction (비무장지대(DMZ) 인근의 훼손지 유형 분석 및 복원방향)

  • Sung, Hyun-Chan;Kim, Su-Ryeon;Kang, Da-In;Seo, Joung-Young;Lee, Sang-Mi
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.19 no.1
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    • pp.185-193
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    • 2016
  • Purpose of this study is to classify damaged lands according to the cause of the damage and their influences based on characteristic of the damaged lands in DeMilitarized Zone(DMZ) area, and utilize this study as a fundamental study for establishment of ecosystem restoration system. Literature review and field survey have been conducted to review the damage status of DMZ area. For field survey, first year and second year have been conducted, in which type of the damage has been reviewed in this study. In the result, types of damage have been classified into 6 categories: 'alteration of initial landform', 'loss of surface layer', 'land pollution', 'alteration of soil chemical property', 'decline of vegetation', and 'invasion of foreign species'. Restoration for each damage type is as following. First, for alteration of initial landform, the land is restored to the original landform prior to the damage and connection to surrounding ecosystem is considered. Second, for loss of surface layer, lost surface layer is restored or further loss is prevented with stabilization. Third, for land pollution, source of the pollution is eradicated or self-circulation with purification of polluted land is encouraged. Fourth, for alteration of soil chemical property, soil is restored of its original property with eradication of the pollution source and improvement of soil. Fifth, for decline of vegetation, current vegetation and anticipated alteration in future are considered and number of wild species is to be increased based on structure and characteristic of nearby vegetation. Sixth, for invasion of foreign species, prevention of dominance by risky species and facilitation ecological stability with ecological management are to be considered. Influence according to the cause of damage has occurred in secondary(indirect) influence or simultaneous occurrence of several damage types. Considering all these aspects, when type of the damage is complex, restoration process for each of former mentioned 6 damage types with solitary influence should be considered in unison.

Runoff Characteristics of Nutrients from Agroforest Culture Field (산림농업지대에서 식물영양물질의 유출특성)

  • Kim, Eun-Hyeok;Cho, Jae-Young
    • Journal of Applied Biological Chemistry
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    • v.57 no.4
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    • pp.331-336
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    • 2014
  • Sediment and nutrient loading caused by the forest to conversion of agricultural lands have led to the deterioration in near water ecosystem. This study was carried out to examine the effects of agroforest culture field and open field culture field on water quality and runoff loading of nutrient. The runoff loading of Tot-N and Tot-P in agroforest culture field were similar to open field culture field. The runoff loading of total suspended solids (TSS) in agroforest culture field and open field culture field were $2,721kg{\pm}196/10a$ and $420{\pm}29kg/10a$ in 2011 and $696kg{\pm}59/10a$ and $463{\pm}36kg/10a$ in 2012, respectively. Our investigation showed that the runoff loading of TSS from agroforest culture field decreased when soil cover and soil stabilization increased. Therefore, protect facility of soil erosion for early alteration of agricultural lands are needed to minimize the soil erosion from agroforest culture field.

Emerging Remediation Technologies for the Contaminated Soil/Groundwater in the Metal Mining Areas (금속광산지역 오염 토양/지하수의 복원기술 동향)

  • 김경웅
    • Economic and Environmental Geology
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    • v.37 no.1
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    • pp.99-106
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    • 2004
  • Pollution reduction and/or control technology becomes one of the pressing post-semiconductor research field to lead an advanced industrial structure. Soil/groundwater remediation techniques may act as a core technology which will create many demands on pollution reduction areas. A plenty numbers of abandoned metal mines were left without any remediation action in Korea, and it may be potential sources of heavy metal and As contamination in the ecosystem. In order to bring this soil contamination to a settlement, the emerging soil/groundwater remediation techniques should be introduced. Main research topics in the United States and Europe move towards the clean remediation technology without any secondary impact and the feasible application of developing technique into the field scale study. With these advantages, several soil/groundwater techniques such as electrokinetic soil processing, permeable reactive barrier, stabilization/solidification, biosorption, soil flushing with biosurfactant, bioleaching and phytoremediation will be summarized in this paper.

The effect of dead coral skeletons on the water quality and sessile mollusks in the closed system (폐쇄시스템 내에서 죽은 산호골격이 수질과 고착성 연체동물에 미치는 영향)

  • Lee, Nam Hyeon;Han, Kyung Nam
    • The Korean Journal of Malacology
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    • v.28 no.3
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    • pp.187-196
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    • 2012
  • Recently, for the purpose of constructing artificial ecosystem, the public aquarium and experimental mesocosm systems are receiving attention. To design and establish an aquarium and mesocosm system, there is need of several materials for simulating the environment, such as sediments, rocks, and plants. Expecially for sessile mollusks, there must be proper materials to which sessile invertebrates can adhere. Nowadays, many aquariums and mesocosm systems are using dead coral skeletons for sessile mollusks. This study was proceeded to have data on the effect of dead coral skeletons on water qualities with the experiment on the environmental factors. For this purpose, I made glass tank for experiment, chose two types of dead coral skeletons imported from the Indonesia and observed the change of water qualities and decomposition efficiency of TAN (total ammonia-nitrogen), nitrite ($NO_2{^-}$) and nitrate ($NO_3{^-}$). As a result, the lager the surface area was, the more TAN, nitrite and nitrate decomposition rate increased. In addition, coral skeletons covered with crustose algae and bacteria in the tank showed faster TAN, nitrite and nitrate removal rate and stabilization. Accordingly, this experiment suggested that dead coral skeletons could be used as a sub filter for the closed system as well as an adhering plate.