• Korean Journal of Soil Science and Fertilizer
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• v.47 no.6
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• pp.443-450
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• 2014

To determine Pb species in soils following the immobilization process, sequential extraction has been used despite the possibility of overestimating Pb species from unintended reactions during chemical extraction. Meanwhile, the application of extended X-ray absorption fine structure (EXAFS) has been shown to provide a more precise result than chemical extraction. In this study, the immobilization of Pb in contaminated soils treated with liming materials such as oyster shell (OS) or eggshell (ES) was evaluated with thermodynamic modelling and EXAFS analysis. Thermodynamic modelling by visual MINTEQ predicted the precipitation of $Pb(OH)_2$ in OS and ES treated soils. In particular, the values of saturation index (SI) for $Pb(OH)_2$ in OS (SI=0.286) and ES (SI=0.453) treated soils were greater than in the control soil (SI=0.281). Linear combination fitting (LCF) analysis confirmed the presence of $C_{12}H_{10}O_{14}Pb_3$ (lead citrate, 44.7%) by citric acid from plant root, Pb-gibbsite (Pb adsorbed gibbsite, 26.4%), and Pb-kaolinite (Pb adsorbed kaolinite, 20.3%) in the control soil. On the other hand, $Pb(OH)_2$ (16.8%), Pb-gibbsite (39.3%), and Pb-kaolinite (25.6%) were observed in the OS treated soil and $Pb(OH)_2$ (55.2%) and Pb-gibbsite (33.8%) were also confirmed in the ES treated soil. Our results indicate that the treatment with OS and ES immobilizes Pb by adsorption of Pb onto the soil minerals as a result of the increase in soil negative charge and the formation of stable $Pb(OH)_2$ under high pH condition of soils.

• Journal of the Korean Geotechnical Society
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• v.17 no.5
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• pp.51-60
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• 2001

연안역 굴양식장에서 발생하여 폐기물로 분류되어 불법으로 버려지는 굴패각을 파쇄하여 혼합한 모르타르 혼합토의 특성을 규명하고자 압축강도 시험을 포함한 다양한 실내시험을 수행하였다. 압축강도시험을 위하여 준비한 모르타르 공시체는 시멘트, 물, 모래 및 굴패각을 다양한 배합비로 혼합하여 제작하였다. 강도시험결과에 따르면 분쇄한 굴패각의 비율이 최대 모래중량의 40%까지 혼합한 경우에도 굴패각을 섞지 않은 일반 모르타르 혼합토에 비하여 압축강도가 크게 감소하지 않았다. 본 연구에서 수행한 압축강도실험을 분석한 결과, 다양한 크기로 파쇄한 굴패각을 적절한 혼합비의 모래 및 시멘트와 배합하여 사용한다면 건설재료로서의 재활용 가능성이 충분한 것으로 판단되었다.

• Journal of the Korean Geotechnical Society
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• v.17 no.4
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• pp.183-190
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• 2001

굴패각을 혼합한 해성점토를 매립재료로 활용하기 위한 기초 자료를 얻기 위해, 혼합토의 전단.변형특성을 검토했다. 또한 삼축압축실험과 균질화이론을 근거로 한 수치해석에 의해 혼합재(굴패각)의 겉보기 탄성계수를 구하기 위한 방법을 제안했다. 일련의 실험결과로부터, 굴패각의 혼합에 의해 점토의 전단.변형특성이 개선됨을 확인했고, 굴패각의 겉보기 탄성계수를 구하기 위해 미시구조를 검토할 수 있는 균질화법을 도입했다. 굴패각의 겉보기 탄성계수는 굴패각의 골격구조의 변화에 기인해 변화하고 선행압밀응력이 작은 경우에 그 영향이 크게 나타나는 것을 알 수 있었다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.275-278
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• 2002

In this study, to increase removal efficiency of traditional electrokinetic treatment and to reduce contaminant load of wastewater that discharged through cathode compartment, enhanced electrode compartments were investigated. Hydroxide precipitation near the cathode electrode that encounter during traditional electrokinetic treatment were prevented by enhanced electrokinetic remediation test with newly invented electrode compartment. And heavy metal concentration in wastewater showed 0 ppm thus, additive post-treatment cost were not needed.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.614-620
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• 2016

Mine soils are usually unfavorable for plant growth due to their acidic condition and low contents of organic matter and nutrients. To investigate the effect of organic material and lime on nitrogen processes in an acidic metal mine soil, we conducted an incubation experiment with treating livestock manure compost, dolomite, and oyster shell and measured soil pH, dehydrogenase activity, and concentration of soil inorganic N ($NH_4{^+}$ and $NO_3{^-}$). Compost increased not only soil inorganic N concentration, but also soil pH from 4.4 to 4.8 and dehydrogenase activity from 2.4 to $3.9{\mu}g\;TPF\;g^{-1}day^{-1}$. Applying lime with compost significantly (P<0.05) increased soil pH (5.9-6.4) and dehydrogenase activity ($4.3-7.0{\mu}g\;TPF\;g^{-1}day^{-1}$) compared with applying only compost. Here, the variation in dehydrogenase activity was significantly (P<0.05) correlated with that in soil pH. Soil inorganic N decreased with time by 14 days after treatment (DAT) due to N immobilization, but increased with time after 14 DAT. At 28 DAT, soil inorganic N was significantly (P<0.05) higher in the lime treatments than the only compost treatment. Especially the enhanced dehydrogenase activity in the lime treatments would increase soil inorganic N due to the favored mineralization of organic matter. Although compost and lime increased soil microbial biomass and enzyme activity, ammonia oxidation still proceeded slowly. We concluded that compost and lime in acidic mine soils could increase soil microbial activity and inorganic N concentration, but considerable ammonium could remain for a relatively long time.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.73-82
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• 2023

This study was conducted to investigate the effect of soil physico-chemical properties and crop growth responses for application of biochar derived from substrate with post harvest of oyster mushroom. The biochar was produced at 450~600℃ using a top-light up draft gasifier (TLUD) production system. As a result of elemental analysis, the biochar used was C 76.2%, H 2.5%, N 3.2%, and H/C was 0.39, which met the international certification standards for biocarbons (IBI) below 0.7. The chemical properties were 10.1 for pH, 1.0% for P₂O₅, 1.8% for K₂O, and 2.5% for CaO. The application rates of biochar were 0, 100, 200, 300, and 500 kg/10a. For cultivation of chinese cabbage and welsh onion, soil organic matter (OM), total nitrogen (T-N), total carbon (T-C), Ex.cation K contents and cation exchange capacity (CEC) in the treatments were increased compared to the no treatment. In addition, the bulk density was lowered and the porosity was increased, improving the soil physical properties in the treated soil. The growth of chinese cabbage and green onion increased with the application of biochar, but the yields of chinese cabbage and green onion did not significantly different among the treatments. Soil carbon sequestration in the treatments enhanced with increasing the amount of biochar application. It is expected to apply the biochar derived from spent oyster mushroom substrate in the eco-friendly farm soil management, improving soil physico-chemical properties.

• Economic and Environmental Geology
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• v.53 no.5
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• pp.517-528
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• 2020

The objectives of this study were to select optimal soil amendments through analysis of heavy metal availability in soil and uptake to Miscanthus sinensis Anderss. for phytostablization in heavy metal contaminated soil of abandoned metal mine. M. sinensis was cultivated for 6 months at contaminated soil with several soil treatments (bottom ash 1 and 2%, fly ash 1 and 2%, waste lime+oyster 1 and 2%, acid mine drainage sludge (AMDS) 10 and 20%, compost 3.4%, and control). The analysis results of heavy metal concentrations in the soil by Mehlich-3 mehthod, growth and heavy metal concentrations of M. sinensis showed that AMDS 20% was more effective than other amendments for phytostablization, and AMDS 10% showed second effectiveness. Waste lime+oyster, bottom ash and fly ash were also improved compared to control. Mobility of some heavy metal was increased by treatments. Therefore, it is necessary of preparatory investigation of soil condition to select soil amendment to apply on-site phytostablization.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.4
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• pp.350-355
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• 1995

This study was conducted to use oyster shells, which have caused environmental problems in the coastal of Korea, as an agricultural material after processing. Physico-chemical components and neutralizing amount on the Ihyun silt loam of crushed oyster shell and slaked lime were examined. In field experiment, the properties of the soil, growth and yield of lettuce, cabbage, spinach, onion, red pepper and soybean were examined by the treatments of the shell(3.68ton/ha) or the lime (2.76ton/ha) with a randomized block design. Particle size of crushed oyster shell consisted of 73.4% of 1~60mesh and 26.6% larger then 61 mesh and contents of CaO, OM, and $P_2O_5$, etc. were 55.5%, 1.3%, and 0.29%, respectively. The requirement of the shell to neutralize the soil was 130~135% of the lime, but after 24months, it was the same. The application of the shell increased the contents of available $P_2O_5$ and $SiO_2$ exchangeable Ca in used soil. The shell tratment increased the leaf height, leaf width, etc. of the examined plants, and the yields 6~154% according to examined plants, as compared with the nonliminged, indicating that the shell possesses a great potential as an agricultural material with the same effectiveness as the lime.

• International Journal of Industrial Entomology and Biomaterials
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• v.8 no.1
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• pp.61-66
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• 2004

Bacillus thuringiensis 656-3 which was isolated from a soil sample of mushroom house and showed high toxicity to mushroom flies, Lycoliella mali and Coboldia fuscipes, was surveyed for insecticidal effect in the oyster mushroom house.3. thutingiensis 656-3 was mass-cultured in the fermenter containing soybean cake(2%) and wheat bran (2%) as media source. Semi-for-mutation of B. thuringiensis 656-3 was performed with metamorphic starch only. When the formulation suspension containing $5{\times}{10^7}$ cfu was sprayed on the mushroom in mushroom house, the insecticidal effect of B. thuringiensis 656-3 to mushroom flies,1. mali and C. fuscipes, was maintained over 90% by the fifth day after starting spraying. The yield of oyster mushroom house with B. thuringiensis 656-3 was significantly increased compared to control. B. thuringiensis 656-3 represents a powerful biological insecticide for the control of mushroom flies.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.471-478
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• 2018

The purpose of this study was to investigate effects of reusable organic wastes, on soil organisms and chemical properties. Bone meal, de-oiled cake, and oyster shell were applied and abundances of soil organisms were measured at 3 and 15 months, after treatment in soil under sawleaf zelkova cultivation. Soil organisms are affected, by the quality of applied organic wastes. Abundance of microorganisms was higher in oyster shell treated soils than in untreated soils, suggesting that soil pH is a driving force, altering abundance and structure of the microbial community. Increase in abundance of bacterivorous nematodes was observed under treatment with bone meal and de-oiled cake, but there was slight change in abundance of fungivorous and herbivorous nematodes. Abundance of herbivorous nematode was positively correlated with plant growth, at 15 months after treatment. Response of microarthropods in the Collembola and Oribatida was not apparent. Abundances of primary consumers were not significantly correlated with microorganisms. This study suggested that organic waste influences soil organisms primarily by altering soil chemical properties and bottom-up effects may not occur in trophic reactions.