• Title/Summary/Keyword: Soil mineral

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Pedological Characteristics of Asian Dust in Korea (한국에 강하한 황사의 토양학적 특성)

  • Zhang, Yong-Seon;Kim, Yoo-Hak;Sonn, Yeon-Kyu;Lee, Gye-Jun;Kim, Myung-Sook;Kim, Sun-Kwan;Weon, Hang-Yeon;Joa, Jae-Ho;Eom, Ki-Cheol;Kim, Sang-Hyo;Kwak, Han-Kang;Kim, Han-Myeong
    • Korean Journal of Soil Science and Fertilizer
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    • v.38 no.6
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    • pp.301-306
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    • 2005
  • Asian dust was collected in Korea and soils in the arid area of northern China were analysed for its physical and chemical properties, and mineral compositions for in order to interpret the origin of Aeolian soils and estimate the effect of dust wind on the soil environment in Korea. Asian dust was collected at Suwon in Korea from 2002 to 2004. Soil samples were collected from the desert and Loess plateaus around Gobi desert in China. As a result of analysis of desert soil distributed on northern region and Loess soils in China, it was observed that soil pH was about 9, organic matter 11 to $23g\;kg^{-1}$, and CEC 7.1 to $18.4cmolc\;kg^{-1}$, showing a high spatial variation among different sampling locations. About 62 to 80% of particles were composed of quartz and feldspars, 2 to 14% calcite ($CaCO_3$) and dolomite [$Ca{\cdot}Mg(CO_3)_2$], and trace other clay minerals. All the dust particles in Korea were below 50 m in diameter, and the mineral compositions were quartz, mica, feldspar and some clay minerals. Major components of clay mineral of Asian dust was mainly illite as compared to the kaolin of soils in Korea. The base saturation of exchangeable Ca, Mg, K and Na in the Asian dust was above 250% due to the high content calcite. Most of upland soil in Suwon was thin and sharp type, but Asian dust in Korea was the spherical shape. Asian dusts in Suwon, Korea, did not show a definite mineralogical variation of the dust during the collection period. Difference between the Asian dust collected in Korea and the soils in arid area of China was observed in the physical and chemical properties, especially for particle size distribution, cations such as Ca, Mg, K and Na. However, some similarities were found on the mineral compositions and chemical properties between Asian dust collected in Korea and the loess of China.

Late Pleistocene Fluvial Sequence in South Korea

  • Kim, Ju-Yong;Yang, Dong-Yoon;Nahm, Wook-Hyun;Lee, Yung-Jo;Park, Ji-Hoon
    • The Korean Journal of Quaternary Research
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    • v.18 no.2 s.23
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    • pp.33-42
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    • 2004
  • In South Korea a Pedo-sedimentary Sequence(PS) indicating the Last Glacial Maximun(LGM) is typified y a brown to dark brown, relatively stiff paleosol layers formed by repetitive freezing and thawing processes which in turn left characteristi glossic textures in soil-solum, polygolnal structures with a flagipans, vertical soil wedges or freezing cracks, and horizontal foliations, As a pre-LGM sedimentary sequences (older than 25Ka), the Old Fluvial Sequence(OFS) overlain by the Slope Sedimentary Sequence(SS) are distributed commonly at the base level higher than 14-15m above present river-bed along the major river basin. After the LGM (ca. 18Ka), the Young Fluvial Sequence(YFS) appears at an altitude ascending order of sedimentary profiles. In this fluvial organic muds of Jangheungri site(Jinju), Sorori site(Cheonwon), and Youngsan estruarine rivermouth(Mokpo) were exemplified in order to interpret their formation ages and environments. As result of $^{14}C$ datings, the formation ages of te organic muds are Boelling to Alleroed (MIS-1). These organic muds were fomed in fluvial backswamp or local pond/bog in response to shifting fluvial system. On the basis of palynological production dominant with Abies/Picea-Betula and Ranunculaceae, Compositae, Cyperaceae, and Graminae, it was interpreted that more boreal to subboreal condition was prevailed rather than temperate like today during the formation of organic muds and soil moisture condition was a repetition of wet and dry condition.

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Impact of Climate Change on the Groundwater Recharge and Groundwater Level Variations in Pyoseon Watershed of Jeju Island, Korea (기후 변화에 따른 제주도 표선 유역의 함양률 및 수위변화 예측)

  • Shin, Esther;Koh, Eun-Hee;Ha, Kyoochul;Lee, Eunhee;Lee, Kang-Kun
    • Journal of Soil and Groundwater Environment
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    • v.21 no.6
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    • pp.22-35
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    • 2016
  • Global climate change could have an impact on hydrological process of a watershed and result in problems with future water supply by influencing the recharge process into the aquifer. This study aims to assess the change of groundwater recharge rate by climate change and to predict the sustainability of groundwater resource in Pyoseon watershed, Jeju Island. For the prediction, the groundwater recharge rate of the study area was estimated based on two future climate scenarios (RCP 4.5, RCP 8.5) by using the Soil Water Balance (SWB) computer code. The calculated groundwater recharge rate was used for groundwater flow simulation and the change of groundwater level according to the climate change was predicted using a numerical simulation program (FEFLOW 6.1). The average recharge rate from 2020 to 2100 was predicted to decrease by 10~12% compared to the current situation (1990~2015) while the evapotranspiration and the direct runoff rate would increase at both climate scenarios. The decrease in groundwater recharge rate due to the climate change results in the decline of groundwater level. In some monitoring wells, the predicted mean groundwater level at the year of the lowest water level was estimated to be lower by 60~70 m than the current situation. The model also predicted that temporal fluctuation of groundwater recharge, runoff and evapotranspiration would become more severe as a result of climate change, making the sustainable management of water resource more challenging in the future. Our study results demonstrate that the future availability of water resources highly depends on climate change. Thus, intensive studies on climate changes and water resources should be performed based on the sufficient data, advanced climate change scenarios, and improved modeling methodology.

Suppression of Pyrite Oxidation by Formation of Iron Hydroxide and Fe(III)-silicate Complex under Highly Oxidizing Condition

  • Lee, Jin-Soo;Chon, Chul-Min;Kim, Jae-Gon
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.2
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    • pp.297-302
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    • 2011
  • Acid drainage generated by pyrite oxidation has caused the acidification of soil and surface water, the heavy metal contamination and the corrosion of structures in abandoned mine and construction sites. The applicability of Na-acetate (Na-OAc) buffer and/or Na-silicate solution was tested for suppressing pyrite oxidation by reacting pyrite containing rock and treating solution and by analyzing solution chemistry after the reaction. A finely ground Mesozoic andesite containing 10.99% of pyrite and four types of reacting solutions were used in the applicability test: 1) $H_2O_2$, 2) $H_2O_2$ and Na-silicate, 3) $H_2O_2$ and 0.01M Na-OAc buffer at pH 6.0, and 4) $H_2O_2$, Na-silicate and 0.01M Na-OAc buffer at pH 6.0. The pH in the solution after the reaction with the andesite sample and the solutions was decreased with increasing the initial $H_2O_2$ concentration but the concentrations of Fe and $SO_4^{2-}$ were increased 10 - 20 times. However, the pH of the solution after the reaction increased and the concentrations of Fe and $SO_4^{2-}$ decreased in the presence of Na-acetate buffer and with increasing Na-silicate concentration at the same $H_2O_2$ concentration. The solution chemistry indicates that Na-OAc buffer and Na-silicate suppress the oxidation of pyrite due to the formation of Fe-hydroxide and Fe-silicate complex and their coating on the pyrite surface. The effect of Na-OAc buffer and Na-silicate on reduction of pyrite oxidation was also confirmed with the surface examination of pyrite using scanning electron microscopy (SEM). The result of this study implies that the treatment of pyrite containing material with the Na-OAc buffer and Na-silicate solution reduces the generation of acid drainage.

Trend and Barrier in the Patents of Artificial Recharge for Securing Goundwater (지하수자원 확보를 위한 인공함양 기술 특허동향 및 장벽 분석)

  • Kim, Yong-Cheol;Seo, Jeong-A;Ko, Kyung-Seok
    • Journal of Soil and Groundwater Environment
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    • v.17 no.3
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    • pp.59-75
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    • 2012
  • It is getting difficult to manage water resources in South Korea because more than half of annual precipitation is concentrated in the summer season and its intensity is getting severe due to global warming and climate change. Artificial recharge schemes can be a useful method to manage water resources in Korea adapting to climate change. Patent analysis enables us to prevent overlapping investment and to find out unoccupied technology. In this study, international patent trends and barriers of artificial recharge technology are analysed for patents of Korea, Japan, the United States and Europe. The four artificial recharge methods such as well recharge, surface infiltration, bank filtration and underground structures are classified as main class and the nine sub-technologies such as water intake, water treatment, injection wells, monitoring of groundwater flow, groundwater pumping, surface infiltration/soil aquifer treatment, radial collection well, iron/manganese treatment, and underground subsurface dam are classified as intermediate class. Water intake techniques are subdivided into five classifications. Total 1,281 of patents, searched by WIPS DB tool and selected after removing noisy patents, are analyzed quantitatively to evaluate application trends by year, applicant, country for each classified technologies and analyzed qualitatively to find out occupied and unoccupied technologies. It is expected that upcoming research and development project could be performed efficiently in that an avoidance plan for the similar patents and differentiation plan for the advancing patents are set up based on the quantitative and qualitative analysis results from this research.

Assessment of Carbon Storage Capacity of Stands in Abandoned Coal Mine Forest Rehabilitation Areas over time for its Development of Management Strategy (폐탄광 산림복구지 관리방안 도출을 위한 산림복구 후 시간경과에 따른 임분탄소저장량 평가)

  • Mun Ho Jung;Kwan In Park;Ji Hye Kim;Won Hyun Ji
    • Journal of Environmental Science International
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    • v.32 no.4
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    • pp.233-242
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    • 2023
  • The objective of this study was to develop a management strategy for the recovery of carbon storage capacity of abandoned coal mine forest rehabilitation area. For the purpose, the biomass and stand carbon storage over time after the forest rehabilitation by tree type for Betula platyphylla, Pinus densiflora, and Alnus hirsuta trees which are major tree species widely planted for the forest rehabilitation in the abandoned coal mine were calculated, and compared them with general forest. The carbon storage in abandoned coal mine forest rehabilitation areas was lower than that in general forests, and based on tree species, Pinus densiflora stored 48.9%, Alnus hirsuta 41.1%, and Betula platyphylla 27.0%. This low carbon storage is thought to be caused by poor growth because soil chemical properties, such as low TOC and total nitrogen content, in the soil of abandoned coal mine forest rehabilitation areas, were adverse to vegetation growth compared to those in general forests. DBH, stand biomass, and stand carbon storage tended to increase after forest rehabilitation over time, whereas stand density decreased. Stand' biomass and carbon storage increased as DBH and stand density increased, but there was a negative correlation between stand density and DBH. Therefore, after forest rehabilitation, growth status should be monitored, an appropriate growth space for trees should be maintained by thinning and pruning, and the soil chemical properties such as fertilization must be managed. It is expected that the carbon storage capacity the forest rehabilitation area could be restored to a level similar to that of general forests.

Sustainable Soil and Groundwater Management: Concepts, Current Research Trends, and Future Perspectives (지속 가능 토양 지하수 관리: 개념, 연구동향, 미래전망)

  • Eunhee Lee;Kitae Baek;Eun Hea Jho;Yongju, Choi
    • Journal of Soil and Groundwater Environment
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    • v.28 no.spc
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    • pp.1-17
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    • 2023
  • Sustainability is commonly recognized as one of the new paradigms or norms that will reign the new era after the modern age of revolutionary economic development. This global trend calls for the adoption of the sustainability concept to soil and groundwater management. In fact, there are several such ongoing movements in practicing soil and groundwater management. Through literature review, this paper discusses the concept, practices, and future research needs of sustainable soil and groundwater management. We first discuss the definition of sustainable soil and groundwater management and possible methodologies to gauge or improve the sustainability of soil and groundwater management. Then, we introduce the research topics, exemplary practices, and propose solutions to elaborate sustainability in three representative subfields including soil and groundwater remediation, groundwater management, and soil management. We conclude with suggestions on the future research directions for successful adoption of sustainability concept to soil and groundwater management in the Republic of Korea.

Evaluation of Soil Redox Capacity using Chromium Oxidation-reduction Reactions in Volcanic Ash Soils in Jeju Island (크롬산화환원반응을 이용한 제주도 화산회토양 내 토양산화환원능 평가)

  • Chon, Chul-Min;Ahn, Joo-Sung;Kim, Kue-Young;Park, Ki-Hwa
    • Journal of the Mineralogical Society of Korea
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    • v.21 no.2
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    • pp.161-175
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    • 2008
  • The soil developed from volcanic ash in Jeju Island, Korea, were classified as typical Andisols. The soils had acidic pH, high water contents, high organic matters and clay-silty textures. The crystalline minerals of the samples were mainly composed of ferromagnesian minerals such as olivine and pyroxene, and iron oxides such as magnetite and hematite derived from basaltic materials. A large amount of gibbsite was found at the subsurface horizon as a secondary product from the migration of excessive aluminum. In addition, our study has shown that considerable amounts of poorly ordered minerals like allophane and ferrihydrite were present in Jeju soils. The contents of $SiO_2$ were lower than those of other soil orders, but $A1_2O_3$ and $Fe_2O_3$ contents were higher. These results are some of the important chemical properties of Andisols. The contents of heavy metals were in the range of $84{\sim}198$ for Zn, $56{\sim}414$ for Ni, $38{\sim}150$ for Co, $132{\sim}1164\;mg\;kg^{-1}$ for Cr, which are higher than the worldwide values in most of the soils. Some soil samples contained relatively high levels of Cr exceeding 1000 mg/kg. Mean reduction capacity of the Jeju soils was $6.53\;mg\;L^{-1}$ reduced Cr(VI), 5.1 times higher than that of the non-volcanic ash soils from inland of Korea. The soil reduction capacity of the inland soils had a good correlation with total carbon content (R = 0.90). However, in spite of 20 times higher total carbon contents in the Jeju soils, there was a week negative correlation between the reduction capacity and the carbon content (R = -0.469), suggesting that the reduction capacity of Jeju soils is not mainly controlled by the carbon content and affected by other soil properties. Correlations of the reduction capacity with major elements showed that Al and Fe were closely connected with the reduction capacity in Jeju soil (R = 0.793; R = 0.626 respectively). Moreover, the amounts of Ni, Co and Cr had considerable correlations with the reduction capacity (R = 0.538; R = 0.647; R = 0.468 respectively). In particular, in relation to the behavior of redox-sensitive Cr, the oxidation of the trivalent chromium to mobile and toxic hexavalent chromium can be restricted by the high reduction capacity in Jeju soil. The factors controlling the reduction capacity in Jeju soils may have a close relation with the andic soil properties explained by the presence of considerable allophane and ferrihydrite in the soils.

Spectral Reflectance Characteristics for Five Soils at Chungbuk Prefecture and Tideland Soil Using Remote Sensing Technology (원격탐사(RS) 기법을 이용한 충북지역 5개 토양과 갯벌토양의 분광반사특성)

  • Park, Jong-Hwa;Shin, Yong-Hee;Lee, Sang-Hyuk
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.6 no.1
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    • pp.34-40
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    • 2003
  • The deterioration of agricultural environment, which is characterized by dryness and desertification of land, is one of the main reasons which explain the recent decrease of land productivity. To solve these environmental problems, it is very important to make clear the mechanism between soil, water, vegetation and temperature. The main objective of this study is to provide a soil surface information, which represent a soil reflectance spectrum, by remote sensing technology. The soil reflectance of the soil was measured using a spectro-radiometer in the wavelength range from 300nm to 1100nm. The results suggest that the reflectance properties of soils are related to their mineral composition and soil moisture. Increasing soil moisture resulted in an decrease in the rate of reflectance which leads to parallel curves of soil reflectance spectra.

Case Study of Soil Remediation by Mobile Soil Washing Instillation - Implemetation on Fluoride comtaminated soil in kitakyushu, Japan - (이동식 토양세척설비를 이용한 오염토양 복원 사례 - 일본 키타큐슈시 불소오염토 적용을 중심으로 -)

  • Oh, Seung-Hoon;Cheong, Jun-Gyo;Chang, Chung-Hee
    • Proceedings of the Korean Geotechical Society Conference
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    • 2008.10a
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    • pp.268-276
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    • 2008
  • The status of contaminated soils vary widely ; therefore, the techniques and equipment applicable to the soil concerned should be selected and used after careful consideration. Hyundai Soil Washing is physical-chemical separation based on mining and mineral processing principles for removing a broad range of organic and inorganic contaminants from soil. Mobile plant(capacity 15 tons./hr) was installed for this project. The goals of this project were 1) to verify the applicability of the washing process, which showed reliable results in the pilot plant with various kind of contaminated soils and 2) to promote recycling of the washed soil as a backfill on site. The results revealed that $F^-$ and $Pb^{2+}$ in the soil were effectively washed out to a certain level which washed soil was acceptable for recyeling.

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