• Journal of the Korean Society of Hazard Mitigation
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• v.9 no.4
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• pp.129-134
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• 2009

As a result of improved wastewater treatment facilities, the point source pollution emitted from human and municipal wastes is greatly decreasing. Conversely, the non-point source (NPS) pollution emanated from city streets, rural homes, suburban development, animal feedlot, croplands, and forestry is rapidly increasing. Practically, the main concern of the government is to control NPS pollutants by means of establishing a long term plan in order to protect the aqua-ecosystem. Studies have been conducted to assess the intensity of NPS from various landuses. In Korea, the data on NPS pollutant loadings are limited to few and broadly categorized landuses unlike in USA wherein specific landuses are available. This research aims to characterize the wash-off characteristics of NPS pollutants from forest landuse. Two sites were monitored during 15 storm events from 04/2008 to 10/2008. Mean $BOD_5$ EMCs are 1.13 mg/L and 0.91 mg/L for the two sites, respectively. The results of this research will be a helpful contribution for the assessment of total NPS pollutant loadings.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.3
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• pp.74-81
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• 2013

In this study, the separation efficiency of wind power selector (the direction of the air flow of the air to perform gravity separation method) of municipal solid waste which was landfilled was investigated to reduce amount of waste that is designed to increase the recycling rate of wastes for the ANSYS CFX Program's numerical methods with wind through the separator. When a suction device designed to suction 1000mL of a plastic bag, the separation efficiency was 100% and when the wind speed was 0.9 m /sec or more and when the wind speed was 1.6 m / sec or more, the efficiency of plastic bottles in a mixture of 500mL and 1500mL plastic bottle waste was 100% and the aluminum screening efficiency of 250mL aluminum can was 100 % when the wind speed was 2.3 m / sec. In the last, 5mm thick compressed aluminum can efficiency was 90 % when the wind speed was 2.4 m / sec.

• Advances in environmental research
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• v.9 no.1
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• pp.55-64
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• 2020

The problems with unsorted municipal waste are always associated with disposal issues as it requires a large area for landfilling or high energy used for incineration. In recent years, an autoclaving technique has been considered a promising approach which could minimize the volume of organic waste from being directly disposed or incinerated. In this work, an attempt was done to study the saccharification potential of organic residues under elevated temperature Thermal treatment involving hot water bath was applied to treat the organic residue ranging from 60℃ to 100℃ for 30 and 60 minutes. The result obtained showed an increasing trend for the concentration of glucose and carbohydrate. However, the result for lignocellulose content which contains various component includes extractive, holocellulose, hemicellulose, cellulose and lignin show variation. Based on the thermal treatment carried out, the result indicated that the trend of glucose and carbohydrate content. The highest percentage of glucose that can be obtained 978.602 ㎍/ml which could be obtained at 90℃ at 60 minutes. The carbohydrate also shows an increasing trend with 0.234 mg/ml as the highest peak achieved at 80℃ for 30 minutes treatment. However, it was found that the lignocellulose content varies with temperature and time. The statistical analysis was carried out using two-ways ANOVA shows an interaction effect between the independent variables (temperature and contact time) and the saccharification effects on the food wastes. The result shows a variation in the significant effect of independent variables on the changes in the composition of food waste.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.5
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• pp.209-222
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• 1993

This article is a case study of the ground improvement project which was carried out for manmade landfill. The project area is located near to Kapchun, Teajon and composed of the municipal wastes dumped, demolished building debris, coal ash and industrial waste made between 1983 and 1989. The DDC(dynamic deep compaction) based on the results of the test compaction at two representative locations was carried out from March 16, 1992 to Oct. 25, 1992. Field measurements and laboratory tests were carried out for ground improvement assessment and quality control for the DDC(dynamic deep compaction) work. From the results of field measurements and laboratory tests, it was found that the DDC work was successful: waste landfill was compressed considerably (${\fallingdotseq}$ 15% of full depth); and the strength was increased satisfactorily (${\fallingdotseq}$ 100% of original penetration resistance), Also, it is expected that the results of this work could be a guide to the future DDC work with the similar ground conditions, i.e. man-made landfills.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2006.04a
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• pp.398-401
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• 2006

Two landfills of this study containing municipal wastes without any bottom liner and leachate treatment system have different landfill age, waste volume and most importantly different hydrogeologic settings. The one (Cheonan) is situated in an open flat area while the other (Wonju) is located in a valley. In the interior of the landfills, typical anaerobic conditions revealed by low DO and ${NO_3}^-$ concentrations, negative ORP values, high $NH_3$, alkalinity and $Cl^-$ concentrations were observed. Generally higher levels of contaminants were detected in the dry season while those were greatly lowered in the wet season. Significantly large decrease of Cl concentration in the wet season indicates that the dilution or mixing is one of dominant attenuation mechanisms of leachate. But detailed variation behaviors in the two landfills are largely different and they were most dependent on permeability of surface and subsurface layers. The intermediately permeable surface of 1.he landfills receives part of direct rainfall infiltration but most rainwater is lost to fast runoff. The practically impermeable surface of clayey silt (paddy field) at immediately adjacent to the Cheonan landfill boundary prevented direct rainwater infiltration and hence redox condition of the groundwaters were largely affected by that of the upper landfill and the less permeable materials beneath the paddy fields prohibited dispersion of the landfill leachate into downgradient area. In the Wonju landfill, there exist three different permeability divisions, the landfill region, the sandy open field and the paddy field. Roles of the landfill and paddy regions are very similar to those at the Cheonan. The very permeable sandy field receiving a large amount of rainwater infiltration plays a key role in controlling redox condition of the downgradient area and contaminant migration.

• Journal of the Korean Society for Railway
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• v.12 no.5
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• pp.788-792
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• 2009

Railroad is well known for eco-friendly transportation system. But, for past few decades, there might be happened many contamination acts in railway facility sites. Industrial and municipal solid wastes produced to maintain and fix trains were dumped to underground of railroad depot area. To develop and reconstruct this area, we should remediate the contaminated soil and ground water. This study was conducted to evaluate the soil pollution status of railroad depot and propose the optimum remediation processes. Our investigation showed that main pollutants sources were TPH and some heavy metals from the dump site. The surveying results for the soil under rail track and crossing nose areas showed TPH contamination from crossing nose area causing lubricant agent. It could be use and rehabilitate the railroad facility areas to an intended purpose with an application of well designed in-situ and ex-situ remediation processes.

• Journal of Environmental Science International
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• v.8 no.5
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• pp.593-600
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• 1999

In order to determine the changes of sediment facies and metal levels in surface sediments after the construction of Shiwha Lake, surface sediments were sampled at 8 sites located on the main channel monthly from June, 1995 to August, 1996 and analysed for 12 metals (Al, Fe, Mn, V, Cr, Co, Ni, Cu, Zn, Cd, As and Pb) by ICP/AES and ICP/MS. Two groups of sampling sites(the inner lake with 3 sites and the outer lake with 5 sites) are subdivided by the surface morphology ; the inner lake is a shallow channel area with a gentle slope, while the outer lake is relatively deep and wide channel with a steep slope which has many small distributaries. After the construction of dam, fine terrestrial materials were deposited near the outer lake, which resulted in the change of major sediment facies from sandy silt to mud. With the deposition of fine sediments in the outer lake, anoxic water column induced the formation of sulfide compounds with Cu, Cd, Zn and part of Pb. Metal (Cr, Ni, Cu, Zn and Cd) contents in sediments increased up to twice within 2 years after the construction of dam. This is due to the direct input of industrial and municipal wastes into the lake and the accumulation of metals within the lake. In addition, frequent resuspension of contaminated sediments in a shallow part of the lake may make metal-enriched materials transport near the outer lake with fine terrestrial materials. As the enrichment of Cu, Zn, Cd and part of Pb in the Shiwha Lake may be related to the formation of unstable sulfide compounds by sulfate reduction in anoxic water or sediment column, the effect of mixing with open coastal seawater is discussed.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.226-234
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• 2009

The main objective of this study was to evaluate the effects on shape and size, compressive strength, water absorption and heavy metals leaching with various weight mixing ratios in waste ash brick products using waste recycling MSWI(Municipal Solid Waste Incinerator) bottom ash, steel slag and waste building material. The manufacturing processes for the waste ash brick consist of screening, mixing, conveyor transmission, compaction.forming, and curing steps of raw materials. The weight mixing ratios of steel slag around bottom ash were adjusted within the ranges of 10% to 30%. The reported results show that the width and thickness of the manufactured waste ash brick could be satisfied with $90{\pm}2mm\;and\;57{\pm}2mm$, respectively which are K.S. standards of products qualities. And in case of length, only 20-Ba50Ss30, 20-Ba60Wb20 and 20-Ba50Wb30 for the mixing ratios could be satisfied with $190{\pm}2mm$ that is K.S. standards of products quality. The compressive strength and water absorption for 20-Ba50Ss30 and 20-Ba70Wb10 were over $8N/mm^2$ and below 15% respectively that are K.S. standards of manufactured waste ash brick. The results of tests for the heavy metals leaching in the all manufactured waste ash bricks are also passed to the wastes management regulations. The cost analysis of 20-Ba50Ss30 is evaluated. The manufacturing cost is evaluated 34.3 won/brick with 8 hours and 20tons of raw material per day. Incinerators with problems in bottom ash disposal can therefore derive significant benefits from the application of waste ash brick production.

• Journal of Energy Engineering
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• v.16 no.4
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• pp.194-201
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• 2007

HHV (Higher Heating Value) of biomass fuel is calculated by using ultimate analysis data and has been proposed by using correlation equation, and compared with the experiment the adequacy about each correlation equation with measured HHV and examined. Samples used for experiment are prepared by mixing biomass (i.e. rice husk and sawdust) with organic waste (i.e. polystyrene polypropylene and waste paper) of 10, 30, 50 wt% of composition. Ultimate analysis and measurement of HHV are respectively measured by using KS standard method. The average error value of estimated HHV results is about 880 kJ/kg(about 3.8% of measured HHV). The corresponding correlation coefficients ($R^2$) of experimental result and estimated HHV result are $0.957{\sim}0.996$.

• Journal of the Korea Organic Resources Recycling Association
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• v.16 no.1
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• pp.62-69
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• 2008

There has been a recent trend in Korea that treatments for combustible wastes among municipal solid waste (MSW) by those methods, such as incineration and landfill are restricted as much as possible and Mechanical Biological Treatment (MBT) are encouraged actively in order to promote resource recovery. To build and operate properly these facilities, the physicochemical characteristics of MSW should be analyzed precisely beforehand. In particular, designing a crusher or separator properly which is the main process in MBT facilities of MSW. require the information on the size distribution characteristics of MSW, but they are nor sufficient in the qualities and quantities yet as of now. Accordingly, this study aims to evaluate size distribution characteristics of MSW and its physicochemical characteristics by size. The samples of MSW were collected from detached dwelling area, apartment area, business area, and commercial area of A city in Korea. According to the result of analysis, paper records 29.78~60.02% by wet weight basis, so it was the most regardless of the regions where the wastes were generated. And in terms of element analysis, Carbon(C) was 34.77~44.39%, the largest friction, and Oxygen(O) was the next occupying 19.46~33.71%. As indices of RDFs, Chlorine(Cl) was 0.39~0.83%, so it was less than the standard, 2.0%(by dry weight basis); moreover, Sulfur(S) did not exceed the standard, 0.6%, either. In the size distribution of MSW, waste fraction ranging 50~80mm in diameter was the most in combustible waste while 30~50mm was in incombustible waste.