• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.91-97
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• 2005

The purpose of this research is malodor reduction of food waste leachate by some microorganism. In oder to observe the efficiency of malodor reduction by different microorganisms, 300ml of food waste leachate was fermented by the addition of 10% precultured seed microorganism such as marine algae of Spirulina plantensis, Chlorella vulgaris, the yeast Saccharomyces cerevisae and bacteria Bacillus cereus for 10 days. During the fermentation the change in pH, salinity and sensory evaluations were tested. As the results, the pH values of samples in the beginning were 3.5~4.0. After fermentation they are increased to the level 4.9~7.4. The salinity values of the samples fermented by Spirulina plantensis and Chlorella vulgaris were lowered rapidly. By the sensory evaluation, the efficiency of malodor reduction by Chlorella vulgaris of the marine microalgae showed almost inodorous degree of ordor 1.

• Journal of the Korean Geotechnical Society
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• v.20 no.8
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• pp.29-39
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• 2004

The prediction of landfill settlement is very important for managing land properly, especially in small national land like Korea. It is difficult to express settlement using the consolidation theory because biochemical decomposition is main reason of settlement, and organic materials in landfill are decomposed far long time. In this study, LFG (Landfill Gas) generation characteristics are studied to find long-term settlement analysing model landfills. Two lysimeters are made; one is leachate recycled, and the other is not leachate recycled. The relationship between gas generation and settlement is analysed as a function of time. A mathematical gas generation model is suggested to predict long-term settlement due to biodegradation, and correction coefficient is recommended for long term settlement through model tests. The leachate recirculation system is more effective to accelerate landfill settlement. The appropriate coefficients of gas correction for non-recycled leachate model are 1.4 and 1.7 for recycled system from tests showing 22% of acceleration.

• Applied Biological Chemistry
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• v.13 no.1
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• pp.81-85
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• 1970

In this studies, we isolated a kind of protein from Alisma Canaliculatum by the saline extraction. This protein was found to have a strong protective effects on the denaturation of ${\alpha}-chymotrypsin$ in the solution state. The obtained important results during the studies were as follows, 1. This protein was never hydrolyzed by the ${\alpha}-chymotrypsin$. 2. The denaturation of ${\alpha}-chymotrypsin$ was strongly protected by this sample protein. 3. Isoelectric point of this sample was about 4.7. 4. This sample protein was determined as an antigen but very weak antigenicity was indicated on rabbit.

• Journal of the Korean GEO-environmental Society
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• v.1 no.1
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• pp.65-70
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• 2000

Recently, soil-bentonite mixtures are frequently used as impervious liners for waste disposal sites. In the present work, bentonite composite liner systems have been developed by utilizing Korean zeolitic bentonites. The geomechanical properties of the liner systems, such as strength hydraulic conductivity, etc. have also been studied. The laboratory and field test results showed that uniaxial strengths of the system were improved by addition of bentonite and CaO-based additive to the upper and lower layer of the liner systems, respectively. Hydraulic conductivity values measured on field liner systems showed less $1{\times}10^{-3}cm/s$, which is considered to be minimum regulation requirement for waste disposal sites.

• Magazine of the Korean Society of Agricultural Engineers
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• v.40 no.5
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• pp.43-51
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• 1998

In design and management of sea0dikes, engineers need to study various transient seepage conditions through dikes not only for the sea water infiltration into dikes due to cyclic rises of sea water level also for the seepage flow out from dikes toward the sea due to cyclic drawdown of sea water level. Characteristics of seepage flow toward the sea from dikes are more complicated than as known and remained unclearly. The case of such seepage flow may be explained by figuring out seepage characteristics in filter as a part of sea-dikes. Filters in most sea-dikes in Korea are inevitably placed with reversely inclined shape due to field construction conditions. Most computer programs for seepage analysis based on the various numerical methods give practically acceptable results, but for the case of reversely inclined section of filters any verification to apply them might be needed. In this study, large scaled model tests were executed to verify and understand seepage flow through earth-filled sea-dikes. The results from numerical analysis and model tests show some remarkable differences in pore pressure distribution under cyclic changes of see level, and some of the results need to be considered in design and construction practices with further study.

• Journal of the Korean Geotechnical Society
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• v.20 no.2
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• pp.75-85
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• 2004

Various geosynthetics are widely installed as a liner or a protective layer of waste landfills. The interface shear strength between the layers of geosynthetics in waste landfills is an important parameter to ensure the safety of bottom and cover system design. In this study, estimations of interface shear strength between geomembrane and geotextile or Geosynthetic Clay Liners (GCL) are performed by large direct shear tests. Especially, this research is focused on the effect of moisture within the interface shear strength between geosynthetics, because most interfaces are vulnerable to rain, leachate and groundwater beneath the liners.

• Geotechnical Engineering
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• v.13 no.4
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• pp.75-84
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• 1997

In this paper, the retardation capacity of marine clay and weathered soil of seashore waste landfill is analyzed by using a laboratory column apparatus for organic and inorganic components which can represent the components of the leachate of municipal waste landfill. The results show that sorption capacity marine clay for potassium is larger than that of weathered soil. Lead and cadmium are adsorbed completely at concentrations higher than the real concentrations developed in the landfill. The bottom soils of seashore landfill can also retard some nondegradable components of organics although their sorption capacities for organics were less than those for inorganics.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.111-120
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• 1999

Leachate flow behavior due to intermediate cover soil of low hydraulic conductivity and the applicability of pumping method for reducing the leachate level in the landfill are analyzed with the numerical flow model, MODFLOW. Using the hydraulic conductivity and storativity data obtained from the field pumping and slug tests(Jang and Cho, 1999), the hydraulic condition within the landfill is validated. The optimum rate of pumping, the radius of influence, and the efficiency of horizontal drain are analyzed for reducing the leachate level in the landfill. From the results of the analyses, the barrier effect that the buried cover soil of low hydraulic conductivity prevents the vertical movement of leachate flow through the cover soil, which is found from the in-situ geotechnical studies(Jang and Cho, 1999), is identified again. Also, the installation of horizontal drains to the pumping well can increase the pumping rate from 120 ton/day per a well to 300 ton/day. The length of horizontal drain did not influence significantly on the drawdown-time curve of leachate in the landfill.

• Economic and Environmental Geology
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• v.28 no.3
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• pp.259-269
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• 1995

Column leaching tests were conducted using fresh and weathered pulverised fuel ash of some 17 and 40 years old from two major British power plants, with deionised water and simulated synthetic industrial leachate. The former was to see the leaching behaviour of weathered ash and the latter was to see if the formation of secondary products from water and PFA interaction and ameliorating effect in removing metals from industrial leachates. Fresh PFA liberates elevated concentrations of surface-enriched inorganics, including Ca, Na, K, B, $Cr_{total}$, Li Mo, Se and $SO^{2-}_4$. This might indicate their association with the surface of PFA particles. In the column leaching tests using weathered ash and deionised water, elements are not readily leached but are released more slowly, showing relatively constant concentrations. For the case of weathered ash, some readily soluble surface-enriched elements appears to have been liberated in their early stage of leaching and the liberation of glass associated elements are thought to be more important function in controlling the element concentration. The result from column leaching tests exceed for a number of elements when compared with various Water Standards and suggests the leachate from PFA disposal mound needs dilution to achieve target concentrations. PF A shows element retention effect for many elements, including B, Fe, Zn, Hg, Ni, Li and Mo, in the order of fresh Drax ash > weathered Drax ash > Weathered Meaford ash in retaining capacity. Geochemical modelling using a computer program WATEQ4F reveals some solubility controlling secondary solid products. These include $CaSO_4{\cdot}2H_2O$ for Ca, $Al(OH)_3$ for Al and $Fe(OH)_3$ for Fe.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.4
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• pp.432-438
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• 1996

This study was carried out to prepare information for the establishment of countermeasures for an area contaminated with minewaste from an old zinc mine at Kahak-long in Kwangmyong. Minewaste and bottom sediments from the streams in this area were sampled and were analyzed for Cd, Cu, Pb, and Zn extracted with different solution. Total heavy metal contents in both minewaste and bottom sediments were fairly high. Cadmium and Zn contents in the minewaste and Cd, Cu, Pb, and Zn contents in the bottom sediments extracted with 0.1 N HCl showed a much higher level than those in the background level of paddy soils and in the soils around the other metal mines regardless of the distance from the mine. Sulfide/residue forms of Cd, Cu, Pb, and Zn covered the highest portions for the minewaste. For bottom sediments, sulfide/residue forms of Cu and Zn formed the highest portions, whereas the contents of both carbonate and sulfide/residue forms of Cd and Pb were significant. The lower the pH of the extracting solutions, the more heavy metals extracted from both minewaste and bottom sediments.