• Magazine of the Korean Society of Agricultural Engineers
• /
• v.45 no.1
• /
• pp.55-62
• /
• 2003

Leachate generated from landfill material flows through soil gravitationally downward and. continues to flow until it encounters groundwater, posing the thread of pollution. So selection of liner material having a low permeability and testing method are required. The study was performed to find bentonite content of soil-bentonite mixtures for using as liner and cover of waste landfills. This paper includes results of consolidation tests and permeability tests and evaluates suitability and properties of soil-bentonite mixtures as impervious materials.

• Journal of the Korean GEO-environmental Society
• /
• v.10 no.1
• /
• pp.15-23
• /
• 2009

The aim of this study was an evaluation of closed non-sanitary landfill's stabilization degree and a determination of its an optimal reclamation method. In order to evaluate the stabilization degree, physical compositions of landfill wastes in 21 closed non-sanitary landfills were analyzed. There were 4 major items such as cover soils, organics, combustibles and incombustibles. With respect to the results of physical compositions, it was determined that the waste in 9 sampling sites of closed non-sanitary landfills after 10years of the relief time was not fully stabilized. The closed non-sanitary landfills must be reclaimed as soon as possible. The main material in closed non-sanitary landfills was cover soils and the highest content was 89.96%. Otherwise, the contents in sanitary landfills was small and 9.89~11.12%. Therefore, it was evaluated that the recovered soil by sorting transfer treatment could be reused as on-site cover soils of the reclamating non-sanitary landfills and/or constructing materials.

• Journal of Korean Society of Environmental Engineers
• /
• v.30 no.8
• /
• pp.768-774
• /
• 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 Korean Geosynthetics Society
• /
• v.7 no.2
• /
• pp.49-52
• /
• 2008

Most of waste sludge has generally been disposed in landfill site or dumped in the ocean, which will be banned by the content of its heavy metals according to London Dumping Convention in Korea. Therefore, environmentally friend methods are urgently required for the treatment and disposal of the sewage sludge. Thermal hydrolysis is one of the good treatment methods to solve the sludge problems. In this study, the physical and environmental testing was conducted to evaluate the feasibility of by-product cake from the thermal hydrolysis as liner or cover materials in landfill.

• Journal of the Korean Geosynthetics Society
• /
• v.1 no.1
• /
• pp.3-11
• /
• 2002

The Geotextiles have been used for the protection of Geomembrane and the prevention of clogging phenomenon; however, the material can be easily damaged by construction equipments. It generally recommended to use at least $500g/m^2$ of Geotextile in Korea landfill, but few researcher were performed about the damage of Geotextile. Therefore, we intended to evaluate the potential damage of Geotextile by the traffic load simulating the final cover system in a field scale. Tensile strength and strain were appraised to understand the degree of damaged Geotextile. The tests were conducted under the condition of cross direction of Geotextile. Four different weight of Geotextile was used for the evaluation $500g/m^2$, $700g/m^2$, $1,000g/m^2$ and $1,500g/m^2$. The initial strain of $500g/m^2$ of Geotextile showed 50% that did not meet the standard 60%. The strain of $700g/m^2$ of Geotextile was below the standard after the traffic load test; however, the others met the requirement in the test. In conclusion, the weight of Geotextile used in landfill to protect the Geomembrane should be at least $700g/m^2$ in a view of strain requirement. We expect this study provides fundamental information for the construction of Geotextile in landfill.

• Nuclear Engineering and Technology
• /
• v.54 no.4
• /
• pp.1431-1438
• /
• 2022

In this study, natural radioactivity concentrations and dosimetric values of fly ash samples were evaluated for the landfill area of the coal-fired power plant (CFPP) complex at Binh Thuan, Vietnam. The average activity concentrations of ²³⁸U, ²²⁶Ra, ²³²Th and ⁴⁰K were 93, 77, 92 and 938 Bq kg^-1, respectively. The average results for radon dose, indoor external, internal, and total effective dose equivalent (TEDE) were 5.27, 1.22, 0.16, and 6.65 mSv y^-1, respectively. The average emanation fraction for fly ash were 0.028. The excess lifetime cancer risks (ELCR) were recorded as 20.30×10^-3, 4.26×10^-3, 0.62×10^-3, and 25.61×10^-3 for radon, indoor, outdoor exposures, and total ELCR, respectively. The results indicated that the cover of shielding materials above the landfill area significantly decreased the gamma radiation from the ash and slag in the ascending order: Zeolite < PVC < Soil < Concrete. Total dose of all radionuclides in the landfill site reached its peak at 19.8 years. The obtained data are useful for evaluation of radiation safety when fly ash is used for building material as well as the radiation risk and the overload of the landfill area from operation of these plants for population and workers.

• Journal of Korean Society of Environmental Engineers
• /
• v.27 no.2
• /
• pp.130-137
• /
• 2005

This research programme include investigation of the adsorption behavior of heavy metals and VOCs by Pyrolysis char for using landfill cover material. The volatile potions in the sludge gasified during the pyrolysis period and gave birth to porosity throughout the matrix. The result of the ad/desorption experiment of nitrogen to find out the formation of some pore by the gasification of the volatile matter, we can certify that the pyrolysis char($14.56\;m^2/g$) has increased twice more than the organic wasted sludge($6.68\;m^2/g$) in specific surface area. The pyrolysis char has the adsorption characteristic of medium type of Type II and V in BDDT classification, and showed a little micro pore. In the adsorption experiment of ethylbenzene and toluene, as a result of applying the Freundlich adsorption isotherms, the pyrolysis char was higher in the adsorptivity of ethylbenzene and toluene than the granite and the organic wasted sludge. The results of the heavy metal adsorption test for the char indicated that it had some ability of adsorption. It is suggest that pyrolysis char has some advantages for utilizing as landfill covers because the pyrolysis char can adsorb/absorb hazardous substances from the landfill sites and inhibit the ground water and soil contamination.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.3
• /
• pp.238-247
• /
• 2012

To determine the possibility of solidified se wage sludge for use as a soil cover material in reclaimed land, the growth of energy crops and soil chemical properties investigated in each experimental plots during 2 years (2010 and 2011). The experimental plots consisted of the mixing with solidified sewage sludge plot (SS50), the covering with solidified sewage sludge plot (SS100), and the original reclaimed land plot (ORL) on reclaimed land for the intended landfill in Sudokwon Landfill Site Management Corporation (SLC). Plant height, measured in the second year (2011), was highest in the Geodae 1 grown at plots treated with solidified sewage sludge. The growth of energy crops cultivated in both SS50 and SS100 were better than in ORL. The contents of organic matter (OM) and total nitrogen (T-N) at both SS50 and SS100 were considerably higher than that of the ORL over 2 years. However, the soil from ORL showed higher salinity with high contents of exchangeable $Na^+$ cation than that of SS50 and SS100 over 2 years. We consider that soil chemical and physical properties on reclaimed land used in this study could be improved by the application of solidified sewage sludge due to following reasons. Firstly, the application of solidified sewage sludge may provide soil nutrients on reclaimed land i.e. the growth of energy crops better than in ORL, resulted in more OM and T-N contents in SS50 and SS100. Secondly, the top layers mixed or covered with solidified sewage sludge on reclaimed land may be prevented the salinity accumulation due to capillary rise to surface soil, and improved the cultivation layer for effectively propagating the rhizomes of energy crops. Thus the solidified sewage sludge may be a great soil cover materials for cultivation of bioenergy crops in reclaimed land.

• Journal of the Korean GEO-environmental Society
• /
• v.4 no.4
• /
• pp.25-34
• /
• 2003

This paper is focused on an experimental study in order to investigate the utilization of sewage sludge ash as the cover and liner materials for the waste disposal landfill or as construction materials. A series of tests were performed to evaluate the basic properties, compaction, compressive strength, consolidation, permeability, and CBR of sewage ash. Specially, clay bricks were made as increasing replacement ratio of sewage ash (such as 5, 10, 15, 20, 25, 30%). And tests were fulfilled for its quality. Bentonite and lime were used as the additives to improve permeability properties of sewage sludge ash. As a result of tests, it was shown that the permeability coefficient decreases as increasing bentonite content and the percentage of bentonite was roughly needed 20% to keep the permeability coefficient below $1{\times}10^{-7}cm/sec$. The results of unconfined compression tests show that sewage ash meets the criteria of the unconfined compression strength for cover material. It was shown that the compressive strength decreases as increasing the replacement ratio of sewage sludge ash and the maximum replacement ratio of sewage sludge ash to satisfy the quality standards of the third degree bricks was about 15%.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.30 no.2C
• /
• pp.119-131
• /
• 2010

In this study, beneficial use of ocean contaminated sediments were investigated by laboratory and environmental tests, and their prototypes were released. Dredged material from Ulsan port is used for making cement treated samples and lightweight foamed samples, and various engineering tests were performed to identify the compressibility and stress-strain behaviors. Environmental tests were also performed for the beneficial uses. The values of Cu are a little higher than the suggested standard possible for reusing dredged material and equal to the suggested standard alarming for reusing dredged material, which shows environmental harmfulness for the reuse of construction material. In addition, particle size distribution, compaction test, Atterberg limit tests, specific gravity test, and unit weight test were performed to investigate the use of landfill cover materials. The shear strengths of cement treated soils were found to be enough for reclamation works.