• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1996.12a
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• pp.87-95
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• 1996

The stabilization and reclamation of old disposal sites is becoming more important as significant numbers of disposal sites are closed and abandoned. This technical paper covers an overview of the key issues and methodologies for stabilizing and constructing facilities on old landfills. The slide portion of this presentation also include photographs showing actual construction activities. The key issues that are prevalent in remediating and closing old landfills are : correcting the stormwater flow, leachate breakout, constructing cover caps, controlling landfill gas migration and odors, cleanup groundwater and stabilizing side slopes. Some key techniques for constructing facilities on old landfills include： use of piling, installation of active landfill gas systems, providing LFG barriers under buildings, using utilidors and flexible utility interfaces and designing for site settlement. This Paper provides proven conceptual methods for solving these problems.

• Applied Chemistry for Engineering
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• v.18 no.6
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• pp.612-617
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• 2007

This research was performed to evaluate the effect of 'Food Wastes (FW) Direct Landfilling Prohibition' on characteristics of landfill gas (LFG) and leachate and the appropriateness of current legislation. Approximately 45% (Exp.45) and 15% (Exp.15) of FW were filled in two lysimeters. During 570 days, 1400 L of LFG was generated from Exp.45%, which was much more than 906 L of Exp.15. There was no significant difference of LFG composition between Exp.15 and Exp.45. 2~30 ppmv of odorous hydrogen sulfide was detected in Exp.45, while 2~7 ppmv was in Exp.15. There was also no significant difference in the leachate generation between the two. On day 570, $BOD_5$ of Exp.45 and Exp.15 were 37000 mg/Land 25630 mg/L and $COD_{Cr}$ of Exp.45 and Exp.15 were 45480 mg/L, 30294 mg/L. TOC of Exp.45 was 2~3 times higher than Exp.15. Higher portion of FW in landfilling increased LFG generation. However, it generated more odor and made the quality of leachate. Therefore, 'FW direct Landfilling Prohibition' was evaluated as an appropriate legislation.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.8
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• pp.768-774
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• 2008

To evaluate the effect of the solidified/stabilized sewage sludge on landfill sites, lysimeter tests were conducted. Lysimeters (LR1, LR2, and LR3) were filled with the material(Compost : Fodder : Sand = 10 : 10 : 80) and covered with different types of the cover soils, the G solidified sludge produced from the neutral solidifying chemical agent(LR1), the A solidified sludge produced from the alkali solidifying chemical agent(LR2), and the weathered granite soil(LR3). Those lysimeters were kept at the temperature controlled room with 30 $\pm$ 2$^{\circ}C$ for about 450 days. As the results, it was appeared LR2 > LR1 > LR3 that total gas production rate(L), gas production rate(L/VS(kg)) and cumulative gas(CO$_2$ + CH$_4$) production. There were not significant differences at decrease of the COD$_{Cr}$ in the leachate from LR1 and LR3. Thus, it had been shown that the use of the G solidified sludge as cover soil did not affect the COD$_{Cr}$ in the leachate. The COD$_{Cr}$ from LR2 had been increased since around 250 days because solidified/stabilized sewage sludge became re-slurry. T-N and T-P from LR3 also were higher than LR1 and LR2. Also were, the use of the solidified/stabilized sewage sludge as a cover soil, therefore, did not affect the T-N and T-Pconcentrations in the leachate.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.3
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• pp.90-96
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• 2007

Modern waste management units, so-called "landfills" protect human health and environment from hazardous leachate and gas. Accordingly, it must be constructed with a bottom liner system that includes a gas collection layer. Leachate is the contaminated liquid that drains from the waste material pollutes ground water. For this reason. bottom liner system must have durability and low hydraulic conductivity (in case of compacted clay liner, no more than $1{\times}10^{-7}cm/sec$ ). P county in Kangwon province constructed a solid waste landfill with bottom liner system. In this study. it is mainly introduced that the test results on construction and quality control of bottom liner system by "Multiple composite liner construction technology", which is selected for bottom liner system in P solid waste landfill.

• Journal of the Korean GEO-environmental Society
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• v.9 no.6
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• pp.13-19
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• 2008

The objectives of this paper are to investigate states of these open dumping landfills for managing, utilizing and stabilization of a municipal solid waste landfill site in environmentally secure conditions. The result of the physical analysis of the landfill showed that it is composed of between 29.72-63.84% organic matter, 32.88% vinyl plastic. The environmental assessment of the landfill site confirmed that the landfill is at a maturation phase due to 0.18 of $BOD_5$/CODcr of leachate. VS and FS of TS Was respectively 30.37%, 32.34% and C/N ratio was 21.8. Surface water around landfill was BOD 10.7 mg/g, SS 37.8 mg/g, E-Coli 31,157(MPN/$100m{\ell}$) and Ground water was $COD_{Mn}$ 1.13-1.38 mg/g, $NO_3-N$ 1.025-4.075 mg/g. Leachat indicated T-P 0.002-0.028 mg/g, $NH_3-N$ 4.0-21.0 mg/g. The soil contamination of around landfill didn't appear as below of the regulation of Soil Environment Conservation Act. The Landfill Gas was $CH_4$ 13.25%, $CO_2$ 6.17%, H2S and CO was not detected. Also Surface Water was not detected $CO_2$, $CH_4$, $H_2S$, CO.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.172-185
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• 2009

This paper presents case histories and research projects related to geotechnical challenges at waste landfill sites in Japan. Due to the limitation of inland space available to waste disposal, coastal landfills and the associated containment systems are important considerations, particularly for metropolitan areas. Experimental works on heavy metals mobility using a large column to simulate the redox potential at the coastal landfill sites are introduced. After the closure of landfill sites, they are expected to be utilized as new land space, since new space is difficult to find in urban area. In the redevelopment of such closed landfill sites, there are possibilities of environmental risks, such as generation of toxic gas and leachate, differential settlement of the waste layer, damage to the lining system. Whether the pile installation through the clay layer acting as a landfill bottom barrier is environmentally acceptable or not has been a great concern in the redevelopment of closed waste landfill sites in particular coastal landfill sites. An analytical study to evaluate the cost-effective remedial option for a dumped waste site located along a landslide area, where cut-off wall keyed into the aquitard might elevate groundwater level and thus may not be employed, is presented.

• Journal of Energy Engineering
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• v.23 no.3
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• pp.125-131
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• 2014

In order to increase landfill gas (LFG) production with food waste leachate, this study was confirmed to be acidogenetic conditions for landfill site injection. Thereby, it was conducted for acidogenetic treatments to determine the decrease in viscosity and VFA production. After acidogenesis treatments, solubility of food waste leachate increased approximately 15%, and as a result, UASB and CSTR were similar by reactor type using the change of retention time. Based on the result of the change in viscosity by reactor type, efficiency of UASB showed approximately 11.38% of higher decrease in viscosity as $76.95{\pm}3.27%$ vs. CSTR. Also, VFA production showed the higher increase of 2.01 times (UASB) and 1.76 times (CSTR) respectively at the point of increasing retention time from 3 to 5 days. From the above results, efficiency of UASB in a reactor was relatively higher because large molecular lead to longer retention time than small molecular due to having screen effect in the fixed media.

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.4
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• pp.136-147
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• 2005

Leachate from landfill sites contains high organics, chloride and ammonium nitrogen in concentration which might be potentially major pollutants to surface and groundwater environment. Most of landfill leachate treatment plants in Korea consist of biological processes to remove BOD and nitrogen. However, the efficiencies of refractory organics removal, nitrification and denitrification have not met frequently the national effluent regulation of wastewater treatment facility, especially in winter season. Simultaneous removal of organics and nitrogen from leachate is strongly necessitated to meet the national regulation on effluents from leachate treatment facilities. The intermittently aerated biological activated carbon fluidized bed(IABACFB) process was applied to treat real landfill leachates containing refractory organics and high concentration of ammonium nitrogen. The IABACFB reactor consisted of a single bed in which BAC fluidizing and an aerating column. The fluidized bed is intermittently aerated through the blower located at the aerating column. Experiments were performed to evaluate the applicability of Intermittently Aerated BACFB for simultaneous removal of refractory organic carbon and ammonium nitrogen of leachate. Organics and ammonia nitrogen($NH{_4}{^+}-N$)are oxidized during the aerobic stage, and nitrite-nitrate nitrogen($NO{_x}{^-}-N$) are removed to nitrogen gas through denitrification reaction during anoxic state. The IABACFB reactor condition reached a steady state within 40 days since the reactors had been operated. The blowing mode of 60 min.-On/60 min.-OFF is more compatible to remove TOC and ($NH{_4}{^+}-N$) operated. The blowing mode of 60 min.-On/60 min.-OFF is more compatible to remove TOC and ($NH{_4}{^+}-N$) simultaneously than the mode of 30 min.-On/90 min.-OFF. The average removal efficiencies of TOC, the refractory organic carbon, and the average efficiencies of nitrification and denitrification were 90%, 75%, 80%, 95%, respectively.

• Geophysics and Geophysical Exploration
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• v.8 no.2
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• pp.137-144
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• 2005

In this study, we offered the results of geophysical and geochemical survey on the municipal waste disposal area to delineate the size and extent of leachate contamination. Preliminary to intensive geochemical investigation, we performed two geophysical methods to characterize the survey area. Electromagnetic (EM) and magnetic method were used far site investigation. From the EM method, we can get the information of soil conductivity directly related to the leachate of the contaminations and from magnetic anomalies we can find the boundary of landfill which is not identified on the surface due to soil capping. The results of geophysical survey were well matched to those of geochemical method carried out inside and near the landfill. Electric conductivity (EC) of the groundwater sampled from low resistivity anomaly region of EM result was higher than background value and the border estimated from the magnetic survey showed good agreement with that estimated from the soil gas detection survey.

• Environmental Engineering Research
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• v.19 no.3
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• pp.261-268
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• 2014

Leachate quality and methane emission from pilot-scale lysimeters operated under semi-aerobic and anaerobic conditions were monitored for 650 days. Two semi-aerobic lysimeters were filled with un-compacted and compacted municipal solid wastes whereas two anaerobic lysimeters containing compacted wastes were operated with leachate storage at 50% and 100% of waste height, respectively. Despite having high moisture in wastes and operating under tropical rainfall events, leachate stabilization in semi-aerobic lysimeters took place much faster resulting in BOD reduction by 90% within 60 days, significantly shorter than 180-210 days observed in anaerobic lysimeters. Nitrogen concentration in leachate from semi-aerobic lysimeter could be reduced by 90%. In term of gas emission, semi-aerobic lysimeter with un-compacted wastes had much lower methane emission rate of $2.8g/m^2/day$ compare to anaerobic lysimeters ($62.6g/m^2/day$) through seasonal fluctuation was observed. Nevertheless, semi-aerobic lysimeter with waste compaction has similar performance to anaerobic lysimeter.