• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.4
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• pp.90-96
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• 2011

In order to remediate contaminated soils with heavy metals, many techniques have been developed and proposed. However, weakness for the various techniques has been making application for actual process difficult. They have been led to the necessity for novel techniques. Therefore, in this study, novel techniques which are developing and commercializing recently in domestic/foreign country will be introduced, especially it will be focused on remediation technique for contaminated soil with heavy metals using magnetic material.

• Environmental Analysis Health and Toxicology
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• v.31
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• pp.6.1-6.10
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• 2016

Objectives This study examined the spatial distribution and the extent of soil contamination by heavy metals resulting from primitive, unconventional informal electronic waste recycling in the Agbogbloshie e-waste processing site (AEPS) in Ghana. Methods A total of 132 samples were collected at 100 m intervals, with a handheld global position system used in taking the location data of the soil sample points. Observing all procedural and quality assurance measures, the samples were analyzed for barium (Ba), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn), using X-ray fluorescence. Using environmental risk indices of contamination factor and degree of contamination ($C_{deg}$), we analyzed the individual contribution of each heavy metal contamination and the overall $C_{deg}$. We further used geostatistical techniques of spatial autocorrelation and variability to examine spatial distribution and extent of heavy metal contamination. Results Results from soil analysis showed that heavy metal concentrations were significantly higher than the Canadian Environmental Protection Agency and Dutch environmental standards. In an increasing order, Pb>Cd>Hg>Cu>Zn>Cr>Co>Ba>Ni contributed significantly to the overall $C_{deg}$. Contamination was highest in the main working areas of burning and dismantling sites, indicating the influence of recycling activities. Geostatistical analysis also revealed that heavy metal contamination spreads beyond the main working areas to residential, recreational, farming, and commercial areas. Conclusions Our results show that the studied heavy metals are ubiquitous within AEPS and the significantly high concentration of these metals reflect the contamination factor and $C_{deg}$, indicating soil contamination in AEPS with the nine heavy metals studied.

• Journal of Environmental Science International
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• v.26 no.6
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• pp.797-802
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• 2017

This study aimed to remove organic matter and heavy metals that could affect the recycling of soils contaminated by heavy metals, by means of electrolysis, carried out simultaneously with the leaching of the soil. To ensure better experimental equipment, a soil electrolysis apparatus, equipped with spiral paddles, was used to agitate the heavy-metal-contaminated soil effectively. The heavy-metal-contaminated soil was electrolyzed by varying the voltage to 5 V(Condition 1), 15 V(Condition 2), and 20 V(Condition 3), under the optimal operating conditions of the electrolysis apparatus, as determined through previous studies. The results showed that the pH of the electrolyte solution and the heavy-metal-contaminated soil, after electrolysis, tended to decrease with an increase in voltage. The highest removal efficiencies of TOC and $COD_{Cr}$ were 18.8% and 29.1%, 38.8% and 4.2%, and 33.3% and 50.0%, under conditions 1, 2 and 3, respectively. Heavy metals such as Cd and As were not detected in this experiment. The removal efficiencies of Cu, Pb and Cr were 4.7%, 8.3% and 2.1%, respectively, under Condition 1, while they were 42.9%, 15.2% and 22.1%, respectively, under Condition 2, and 4.7%, 23.0%, and 24.9%, respectively, under Condition 3. These results suggest that varying the voltage with the soil electrolysis apparatus for removing contaminants for the recycling of heavy-metal-contaminated soil allows the selective removal of contaminants. Therefore, the results of this study can be valuable as basic data for future studies on soil remediation.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.09b
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• pp.192-199
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• 2010

This research produced internal model tester ($2.0m{\times}2.0m{\times}1.0m$) to evaluate the field application of Paju Unjeong District water recycling system for small streams eco-friendly river bed disparity method for the first time in Korea and conducted comparative analysis of the Paju Unjeong District water recycling system field test results and infiltration rate result of internal tests by each rainfall intensity following surface material. Infiltration rate result of internal tests concrete pavement by rainfall intensity following surface material, asphalt pavement, bentonite mate, stabilized soil construction and mixed soil construction manifested low infiltration rate. On the contrary, compaction soil, grassland and water permeable packaging materials resulted in significant amount of infiltration rate. As for the field permeability test results, they were manifested similar tendency as indoor permeability test results and they satisfied the standard for standard of water permeability of domestic disparity facility (less than $1.0{\times}10-7cm$/sec). As compaction rate increased, unconfined compression strength increased as well while coefficient of water permeability decreased.

• Journal of the Korean Geosynthetics Society
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• v.11 no.4
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• pp.9-16
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• 2012

Standardized remediation process for the soil contaminated with arsenic is insufficient due to characteristics of its anion-mobility and speciation changed by Eh-pH of soil. One of the well-known efficient remediation processes is the modified soil washing that particle separation process by only water. However, it is required that the treatment plan for the fine soil what was discharged after modified soil washing. Therefore, this research suggests the treatment plan that the recycling method using arsenic immobilization by FeS-$H_2O_2$. The batch experiments results for the arsenic immobilization showed that the water content was at least 50%, the injection of FeS and $H_2O_2$ (assay-35%) were 8% (w/watdrybase) and 0.2 mL/10 g of fine soil respectively. Arsenic concentration with KSLT was decreased about 95.4%. The results indicated that the mixing of FeS-$H_2O_2$ was highly efficient on the immobilization of As-contaminated soil. The mixing ratio as 13% of bentonite with 3% of cement (at based on 100% of immobilized fine soil) was satisfied with standard of liner for landfill construction.

• Resources Recycling
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• v.8 no.3
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• pp.3-8
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• 1999

An air-washer was developed in order to remove the soil on the films collected from agricultural use, The washed films were subjected to TGA analysis to measure the residual soil content and DSC analysis to evaluate composition as well as compositional ratro, Mechanical properties of washed films were measured via tensile test ,md the properties of washed films were compared with those of neat resin blend. Major component of air washed films was polyethylene, and compositional ratio was 10:6:3:1 (HDPE:LLDPE:LDPE:EVA). 30 min air-washed films showed 2.1 % of residual soil content, while the water washed films had 1.5%. Tensile properties of washed (air and water) films were almost same as those of neat resin mixture.

• Economic and Environmental Geology
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• v.54 no.2
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• pp.285-297
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• 2021

Globally, nuclear-decommissioning facilities have been increased in number, and thereby hundreds of thousands of wastes, such as concrete, soil, and metal, have been generated. For this reason, there have been numerous efforts and researches on the development of technology for volume reduction and recycling of solid radioactive wastes, and this study reviewed and examined thoroughly such previous studies. The waste concrete powder is rehydrated by other processes such as grinding and sintering, and the processes rendered aluminate (C3A), C4AF, C3S, and ��-C2S, which are the significant compounds controlling the hydration reaction of concrete and the compressive strength of the solidified matrix. The review of the previous studies confirmed that waste concretes could be used as recycling cement, but there remain problems with the decreasing strength of solidified matrix due to mingling with aggregates. There have been further efforts to improve the performance of recycling concrete via mixing with reactive agents using industrial by-products, such as blast furnace slag and fly ash. As a result, the compressive strength of the solidified matrix was proved to be enhanced. On the contrary, there have been few kinds of researches on manufacturing recycled concretes using soil wastes. Illite and zeolite in soil waste show the high adsorption capacity on radioactive nuclides, and they can be recycled as solidification agents. If the soil wastes are recycled as much as possible, the volume of wastes generated from the decommissioning of nuclear power plants (NPPs) is not only significantly reduced, but collateral benefits also are received because radioactive wastes are safely disposed of by solidification agents made from such soil wastes. Thus, it is required to study the production of non-sintered cement using clay minerals in soil wastes. This paper reviewed related domestic and foreign researches to consider the sustainable recycling of concrete waste from NPPs as recycling cement and utilizing clay minerals in soil waste to produce unsintered cement.

• Proceedings of the Korean Nuclear Society Conference
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• 2001.05a
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• pp.469.1-469
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• 2001

• Journal of the Korea Organic Resources Recycling Association
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• v.13 no.2
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• pp.85-90
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• 2005

Changes of biochemical and genetic diversity of microbial communities in the soil damaged by a forest fire were analyzed. Soil samples were collected from Gangnung area where a forest fire was broken out in 2000. Two soil samples were from the burnt area, one from the naturally restoring soil (NS) and the other from the artificially restoring soil (AS). A normal, unaffected soil sample (US) was also included as a control. For the biochemical diversity, each sample was directly applied to the BIOLOG system, and the cluster analysis through a statistic process (SPSS) were performed. Genetic diversity was analyzed through DGGE using 16S-rDNA amplified from soil DNA. Among the samples tested, top soils of US and NS, and sub soil of NS revealed more than 70% of the similarity value in biochemical diversity. In case of genetic diversity, however, the similarity value was found to be in the range of 53% to 68% in all samples. This result indicates that the biochemical diversity is not always correlated with the genetic diversity in the analysis of microbial communities.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.788-793
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• 2011

To evaluate fertilizer value of animal cadavers for agricultural recycling, fertilizer components of animal cadavers by pig and poultry were investigated using rendering and alkali (KOH) treatment methods. Total nitrogen concentrations in meat waste by pig and poultry using rendering treatment method were 7.80% and 9.30%, respectively. Total nitrogen concentration in meat waste of pig by KOH treatment method was lower than that by rendering treatment method. Organic matter concentrations in meat waste of pig and poultry ranged 87.8~97.4%. Total phosphorus concentrations in bone waste of pig using rendering and KOH treatment methods ranged 5.59~11.18%. Animal cadavers contains nitrogen, phosphorus, potassium and other nutrients essential to plant growth. The results of this study suggest that animal cadavers can supply some of the nutrient requirements of crops and is a valuable fertilizer as well.