• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.41-46
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• 2006

This study was carried out to evaluate the recycled waste soils from construction site for using vegetation media. The concentrations of Cd, Pb, $Cr^{6+}$, As, Hg, Cu, Cn, organic P, TCE, and PCE were measured at recycled soil piles of an industrial waste treating company in the Metropolitan landfill area. The concentrations of polluted materials did not exceed to the standard critical levels of soil pollution in all analyzed items. The results suggested a high potential of recycling of the wastes soils for vegetation soil media. However, Cd and $Cr^{6+}$ almost reached the critical levels by the time of sampling, and it is necessary to develop a skill to lower concentrations of those pollutants. In the turfgrass test, the recycled soil did show an encouraging result as vegetation media in the early growth stage of perennial ryegrass.

• Applied Chemistry for Engineering
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• v.28 no.6
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• pp.685-690
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• 2017

Ammonia is a useful substance which is widely used in various industries. It is generally released by the decomposition of agricultural wastes and known to have toxic effects on human beings. Due to the common usage, it is possible to cause water pollution through either direct or indirect leakage. Such cases, it is preferable to use the adsorption capacity of zeolite to rapidly remove ammonium ions, but it is not sufficiently removed by the adsorption only. In this paper, the removal efficiency of ammonium ion through both the adsorption capacities of commercial synthetic zeolites and the biological mechanism of microorganisms were compared. In addition, microorganisms were immobilized on the zeolite in order to enhance the removal efficiency by applying a chemo-biological process. As a result, the standard commercial zeolite showed 67~81% of the removal efficiency in 2~4 hours at a 100 ppm concentration of ammonium, whereas the selected microorganism Klebsiella pneumoniae subsp. Pneumoniae showed up to 97% within 8 hours. When the microorganism was immobilized on the zeolite, the highest removal efficiency of approximately 98.5% were observed within 8 hours.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.5
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• pp.31-39
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• 2007

This study was carried out to evaluation the recycled waste soils from construction site for planting soil. For this purpose, the concentrations of polluted materials and the physico-chemical properties were measured at recycled soil samples of an industrial waste treating company in the Metropolitan landfill area. The concentrations of polluted materials did not exceed to the standard critical levels of soil pollution in all analyzed items. The measures of the samples soil texture (loamy sand), bulk density (1.09~1.32g/$cm^3$), saturated hydraulic conductivity ($1.6{\times}10^{-3}{\sim}1.8{\times}10^{-3}$cm/sec), solid phase distribution (0.4~0.5$m^3/m^3$), porosity (0.5~0.6$m^3/m^3$), Ex. $K^+$ (1.0~1.2cmol/kg), Ex. $Mg^{2+}$ (0.2~0.6cmol/kg) were identified as not worse than those of conventional planting soil. But the sample soils have serious problems for planting soil such as high levels of pH (9.6~11.5), EC (0.78~1.84ds/m) and Ex. $Ca^{2+}$ (25.6~34.5cmol/kg), low level of organic matter (0.2~0.3%). It is required to improve pH, EC and Ex. $Ca^{2+}$ of sample soils. Consequently, the results suggested a high potential of recycling of the wastes soils for planting soil.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.51-60
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• 1996

Removal of Mn-EDTA complex and fluoride by use of hematite and ferrite, which are the by-product to be disposed of as industrial wastes, was investigated. For the comparison of removal rate, Na-bentonite known as excellent absorbent of inorganic contaminants was included in the experiments. As the results of batch mode experiments, for manganese, ferrite-A revealed 48∼65% of removal capacity, ferrite-B 46∼57%, hematite 17∼26%, while Na-bentonite showed 10∼23% of removal, depending on the initial concentration. Meanwhile, in case of fluoride : hematite revealed 53 ∼63% of removal : ferrite-A 54∼63 %, while ferrite-B did 20∼38 %. From the results, it can be postulated that the capacity of hematite and ferrite to attenuate inorganic pollutants, especially when they form complex ions, is superior to that of Na-bentonite. Consequently, the mixing of such oxide minerals with Na-bentonite will reinforce the function of Na-bentonite, especially in the undergroud liner aspect.

• Journal of the Korean Wood Science and Technology
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• v.39 no.5
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• pp.451-458
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• 2011

Adhesives derived from renewable resources allow wood panel producers to make lower cost alternatives to formaldehyde-based adhesive resins. Among them, adhesive components extracted from industrial by-products or wastes are the most important research fields in the efficient utilization of waste and cost reduction. In our study, the rapeseed flour, which is a by product from the production of biodiesel extracted from rapeseed, was introduced to develop alternative adhesives for the production of wood flooring. The rapeseed flour was hydrolyzed with 1% sodium hydroxide solution and PF prepolymers were prepared with 3-molar ratios, 1.8, 2.1 and 2.4. The linear fracture mechanics was introduced to evaluate the glue bond quality in wood flooring composed of fancy-veneered and plywood, and the formaldehyde emission and adhesive penetration were also investigated. The formaldehyde emissions of wood flooring met the requirement of the standard of $SE_0$ specified in the KS standard. The rapeseed flour adhesive penetrated sufficiently into the vessel elements and lumens in fancy veneer and plywood and gave strong bond quality to the wood flooring. The fracture mechanics was introduced to evaluate the adhesive joint between fancy veneer and plywood. The critical stress intensity factor ($K_{IC}$) of boliva overlayed wood flooring was increased with increasing molar ratio and this was the same tendency in oak overlayed wood flooring. From the results, the formulated adhesives were efficiently used to bond fancy veneer onto the plywood to make wood flooring and showed a potential to be used as a component of environmentally friendly adhesive resin systems for production of flooring.

• International Journal of Concrete Structures and Materials
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• v.8 no.3
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• pp.213-228
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• 2014

Alkali-activated binder (AAB) is recently being considered as a sustainable alternative to portland cement (PC) due to its low carbon dioxide emission and diversion of industrial wastes and by-products such as fly ash and slag from landfills. In order to comprehend the behavior of AAB, detailed knowledge on relations between microstructure and mechanical properties are important. To address the issue, a new approach to characterize hardened pastes of AAB containing fly ash as well as those containing fly ash and slag was adopted using scanning electron microscopy (SEM) and energy dispersive X-ray spectra microanalyses. The volume stoichiometries of the alkali activation reactions were used to estimate the quantities of the sodium aluminosilicate (N-A-S-H) and calcium silicate hydrate (CSH) produced by these reactions. The 3D plots of Si/Al, Na/Al and Ca/Si atom ratios given by the microanalyses were compared with the estimated quantities of CSH(S) to successfully determine the unique chemical compositions of the N-A-S-H and CSH(S) for ten different AAB at three different curing temperatures using a constrained nonlinear least squares optimization formulation by general algebraic modeling system. The results show that the theoretical and experimental quantities of N-A-S-H and CSH(S) were in close agreement with each other. The $R^2$ values were 0.99 for both alkali-activated fly ash and alkali-activated slag binders.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.4
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• pp.29-42
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• 1986

This study is an experimental research on the adsorption capacity and the adsorption system utilizing Discarded Automotive Tires(DAT) and Powdered or Granular Activated Carbon(PAC or GAC) for the removal of heavy metals, Ag(I), Cd(II), Cu(II), Zn(II). Batch shaking test was conducted to determine the adsorption capacity of DA T and PAC in removing the heavy metals from aqueous wastes; and laboratory-scale column experiment was performed to present design factors affecting the optimum design of adsorption column with DAT and GAC, through the concept of Bed Deph/Service Time(BDST). As results, DAT has been proven to be a good adsorbent will its adsorption capacity not falling behind PAC or GAC. Factors affecting heavy metals removals were amount of adsorbents, initial concentrations, pH and so on. BDST equations were compared with values presented by the breakthrough data from adsorption system.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.233-239
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• 2006

As the number of aged-housing has been rapidly increased, many kinds of defects and problems such as degeneration of housing environment, structural performance, and equipment performance have been appeared. The reconstruction as the way to improve the aged-housing has been used mostly because the legal process of the reconstruction is relatively easy. On the other hand, it has caused problems such as the lack of natural aggregate, the environmental damages owing to construction wastes, the loss of national resources, and the lack of the housing for rent nearby the reconstruction area. This problems limit active tying into the reconstruction business at present in the industrial and political perspective. In this context, it is required to revitalize the remodeling rather than the reconstruction. In order to reach this objective, this research aims at identifying the user-oriented performance for the housing industry and developing the new technologies. It is expected that the result of this research can contribute to more revitalize the remodeling as tying researches in terms of design, structure, equipment, and construction.

• Ocean and Polar Research
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• v.30 no.1
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• pp.89-107
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• 2008

Marine environment is subject serious destruction because of frequent accidents during exploration of marine resources and overseas transport. Also, as many industrial enterprises discharge high volume of wastes and contamination, marine pollution has become a serious threat to people (especially in China). China is quickly becoming a world economic leader of the 21st century. Rapid industrialization and social changes have raised the standard of living of millions of the Chinese, mainly in the areas of East and South East coast. The process of industrialization, however, is often followed by deterioration of the marine environment and rarely turned around until a country has increased its standard of living. Solving these array of problems will take decades and currently the government is addressing minor specific issues only. Fortunately, the Chinese government has enacted a number of marine pollution control laws. On 25 December 1999, the 13th Session of the Ninth Standing Commettee of the National People's Congress passed the amended the Marine Environment Protection Law of the People's Republic of China. This Law establishes rights and responsibilities of the relevant departments concerning marine environment management and provides for two new chapters on "Marine Environment Supervision" and "Marine Ecological Protection", along with "Supervision of Pollution Prevention for Marine Construction Projects", "Marine Ecological Protection" and "Marine Environment Pollution Prevention for Marine Construction Projects". Also, the Law was amended with provisions for integrated pollution discharge control system and oil spillage emergency response plan and enhanced legal responsibilities. Chinese government recognizes that international and national experience can be useful for China to prevent further ecological degradation of the marine environment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.28 no.2
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• pp.135-143
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• 2018

Objectives: There have been many studies on exposure assessment of workers at companies using asbestos as a raw material and at sites of the removal of materials containing asbestos. However, no research has been carried out on the asbestos exposure of workers in industries involving asbestos-containing waste, such as workers at collection and transportation service companies, mid-treatment companies(solidification of asbestos-containing waste), and landfill sites. The objective of this study was to assess the asbestos exposure concentrations of workers in industries handling waste containing asbestos. Methods: For this study, we carried out field investigations at 15 companies: seven collection and transportation service companies, three mid-treatment companies, and five final treatment companies(landfill sites). We took both personal and area samples. Results: The range of asbestos exposure levels of workers handing asbestos-containing wastes at collection, mid-treatment, and landfill companies were 0.000 fibers/cc-0.009 fibers/cc, 0.000 fibers/cc-0.038 fibers/cc, and 0.000 fibers/cc-0.024 fibers/cc, respectively. Conclusions: The asbestos exposure levels of workers at mid-treatment companies were higher than those at collection and transportation companies and at final treatment companies. In the case of collection and transportation workers, the possibility of exposure to levels exceeding those found in the present study is not particularly high considering the characteristics of the work. However, in the case of intermediate or final disposal workers, it is considered that there is a possibility of exposure to levels above those found in this study.