• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.640-647
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• 2006

It is difficult to treat wastewater involved in heavy metal in electroplating industry. Recently, many industries adopt the clean technology to prevent production of pollutant in the process or reuse after the appropriate pollutant treatment. In this study, we estimate the ability of recovery of nickel and the efficiency using lab-scale ion exchange and electrodialysis process with electroplating industry wastewater. In the ion exchange experiments with 5 types of resin, the result showed that S 1467(gel-type strong acidic cation exchange resin) has the highest exchange capacity. And it showed that the 4 N HCl has the highest in regeneration efficiency and maximum concentration in the regeneration experiments with various kinds md concentration of the regenerant. During the electrodialysis experiments, we varied the current density, the concentration of electrode rinse solution, the flow rate of concentrate and electrode rinse solution in order to find the optimum operating condition. As a result, we obtained $250A/m^2$ of current density, 2 N $H_2SO_4$ of concentration of electrode rinse solution, 30 mL/min of flow rate of concentrate and electrode rinse solution as the best operating conditions. We performed the scale-up experiments on the basis of ion exchange and electrodialysis experiments. And we obtained the experimental result that exchange capacity of S 1467 was 1.88 eq/L resin, and regeneration efficiency was 93.7% in the ion exchange scale-up experiment, we also got the result that concentration and dilution efficiency increased, and current efficiency kept constant in the scale-up experiments.

• Journal of the Korean Ceramic Society
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• v.42 no.7 s.278
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• pp.475-482
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• 2005

Zn$_{l-x}$Co$_{x}$O (x = 0.05 - 0.20) films were grown on Coming 7059 glass by sol-gel process. A homogeneous and stable Zn$_{l-x}$Co$_{x}$O sol was prepared by dissolving zinc acetate dihydrate (Zn(CH$_{3}$COO)$_{2}$$\cdot$2H$_{2}$O), cobalt acetate tetrahydrate ((CH$_{3}$)$_{2}$$\cdot$CHOH) and aluminium chloride hexahydrate (AlCl$_{3}$ $\cdot$ 6H$_{2}$O) as solute in solution of isopropanol ((CH$_{3}$)$_{2}$$\cdot$CHOH) and monoethanolamine (MEA:H$_{2}$NCH$_{2}$CH$_{2}$OH). The films grown by spin coating method were postheated in air at 650°C for 1 h and annealed in the condition of vacuum (5 $\times$ 10$^{-6}$ Torr) at 300$^{\circ}C$ for 30 min and investigated the nature of c-axis preferred orientation and physical properties with different Co concentrations. Znl_xCOxO thin films with different Co concentrations were well oriented along the c-axis, but especially a highly c-axis oriented Zn$_{l-x}$Co$_{x}$O thin film was grown at 10 at$\%$ Co concentration. The transmittance spectra showed that Zn$_{l-x}$Co$_{x}$O thin films occur typical d-d transitions and sp-d exchange interaction became activated with increasing Co concentration. The electrical resistivity of the films at 10 at$\%$ Co had the lowest value due to the highest c-axis orientation. X-ray photoelectron spectroscopy and alternating gradient magnetometer analyses indicated that no Co metal cluster was formed, and the ferromagnetic properties appeared, respectively. The characteristics of the electrical resistivity and room temperature ferromagnetism of Zn$_{l-x}$Co$_{x}$O thin films suggested the possibility for the application to dilute magnetic semiconductors.

• Composites Research
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• v.32 no.6
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• pp.335-341
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• 2019

In this study, an acrylic acid (AAc) was grafted on a polypropylene (PP) nonwoven fabric using electron beam irradiation. Electron beam grafting was carried out under various conditions to produce AAc grafted PP (PP-g-AAc) nonwoven fabric having a grafting yield of about 50% at radiation dose of 100 kGy and a monomer concentration of 60%. The physical and chemical properties of PP-g-AAc nonwoven fabric were evaluated by SEM, ATR-FTIR, thermal analysis and tensile strength. The morphology of PP and PP-g-AAc nonwoven fabric confirmed by SEM showed no significant change, and it was judged that AAc was introduced into PP nonwoven fabric from ATR-FTIR. PP-g-AAc nonwoven fabric showed an increase in tensile strength and a decrease in tensile strain compared to PP nonwoven fabric. However, since change of value is not significant, it is considered that there is no significant influence on the physical characterization. Adsorption experiments of PP-g-AAc nonwoven fabric on various ions showed selective adsorption behavior for lead ion. In conclusion, the electron beam radiation-induced PP-g-AAc nonwoven fabric is expected to be applied as an effective adsorbent for the adsorption of lead ions.

• Food Science of Animal Resources
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• v.28 no.3
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• pp.373-389
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• 2008

This study was conducted to evaluate exposure level and risk of heavy metals in livestock foodstuffs and Korean foods. Based on the "Food Intake Data," a part of the 2005 National Health & Nutrition Survey and the "2005 Seasonal Nutrition Survey", 113 Korean foods items were selected. 3 samples from different manufacturers of each 113 items of Korean foods were purchased on summer and fall, so total 678 samples were used. The food groups were classified into 15 categories. For the livestock foodstuffs category, meats and poultry (chicken, pork, pork belly, beef, beef feet soup), milks and dairy products (milk, ice cream, liquid yoghourt, sherbet), eggs (egg) were selected. It was found that the daily amount of heavy metals intake (mg/person/day) from livestock foodstuffs is 0.00020 arsenic, 0.00000 cadmium, 0.00020 lead, and 0.00006 mercury, and the daily amount of heavy metals intake (mg/person/day) from Korean foods is 0.0265 arsenic, 0.0083 cadmium, 0.0067 lead, and 0.0028 mercury. Daily amount of heavy metals intake from livestock foodstuffs was low among the food groups. For risk assessment, PDI (Probable Daily Intake) was calculated and compared with PTWI (Provisional Tolerable Weekly Intake) of JECFA (Joint FAO/WHO Expert Committee on Food Additive). Relative hazard of these livestock foodstuffs was 0.006% in arsenic, 0.000% in cadmium, 0.085% in lead, and 0.149% in mercury. Relative hazard of Korean foods was 0.941% in arsenic, 14.676% in cadmium, 3.319% in lead, and 6.860% in mercury. Thus, livestock foodstuffs and Korean foods were as safe as satisfied with the recommended standards of JECFA.

• The Journal of the Korea Contents Association
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• v.13 no.2
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• pp.390-399
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• 2013

The purpose of this study is to examine the impact of enterprise R&D investment on inter-industry technology spillover in Korea under the new Normal Era. In order to do this, we tested the effect of production inducement, backward and forward linkage effects, and the effect of technology spillover such as technology intensity effects and technology diffusion effects based on an input-output framework. The results show that the high index industries of the production inducement effect were professional, scientific and technical activities, manufacture of metal products, and general machinery. Some manufacturers of other non-metallic mineral products and transport equipment sectors appeared to have the strong effect of forward and backward linkages that were almost equivalent to high-tech manufacturing industries. In particular, the industries of professional, scientific and technical activities appeared to have the strong effect of both forward and backward linkages. Therefore, we need to drive a strong policy support to higher enterprise R&D investment in the those particular industries not only to increase global competitiveness, but also to widen up the technology spillover effect on other industries.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.9
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• pp.355-361
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• 2018

Mining is important as a national key industry that supplies energy and raw materials that are the basis for industrial development. On the other hand, mine development is necessarily accompanied by mineralization, for example, ground subsidence, heavy metal pollution, and water pollution. The mine hazard has a large range of damage, and it takes much time and cost to recover. In addition, there is a need for systematic mining management in order to prevent damages from occurring continuously. In this study, the present status of domestic mining industry and geospatial information construction technology for mining management were investigated. 95% of the mines surveyed were nonmetallic, and limestone mines accounted for 67%, and the constructed mine spatial information is not constructed with 3D geospatial information due to 2D current status, section, and geological map. Considering the results of the survey and analysis of 3D laser scanner and characteristics of Korean mine, handheld scanner is considered to be the most suitable method for constructing mine geospatial information. In addition, the data acquired through the 3D laser scanner can effectively visualize the object, and it can contribute to the systematic management of mining because it can be used for various purposes such as generation of drawings and calculation of volume.

• Korean Journal of Environmental Biology
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• v.34 no.3
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• pp.212-215
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• 2016

We developed a new ecotoxicological test method using native test species, eggs of Ephemera orientalis, and five kinds of industrial wastewater were tested to validate the test method. The water samples were collected in Jun 2006 from the following industries: pesticide, metal plating, PCB, leather1, and leather2. Wastewater and effluent were diluted by distilled water, respectively, to prepare various concentrations, 100, 50, 25, 12.5, 6.3, 3.1, and 0%. For the egg bioassay, 20 freshly laid eggs (<24 h old) were exposed to test solutions in a Petri dish ($52{\times}12mm$) at $20^{\circ}C$ with photoperiod of 16 h light and 8 h dark for 14 days. The median egg hatching concentrations (EHC50) were estimated using Probit analysis. All EHC50s of wastewater were less than 3.1%, which meant very high ecotoxicity except for the wastewater of PCB industry having 6.1% of EHC50. Among the effluents, the least toxic effluent was from pesticide industry having 58% of EHC50, while the effluent of leather2 was the most toxic having 7.3% of EHC50.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.373-379
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• 2006

We investigated the relationship of the organic pollutant index in wastewater where the high percentages of an organic load to a water body was found. Measuring of TOC was to identify the relationship with COD and BOD which were used already. The correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD were effected by the types of industry such as paper, textile, chemical, food and metal industries. In food industry it was found that the highest correlation coefficient (r) of TOC/COD, BOD/COD and TOC/BOD as 0.967, 0.969 and 0.990, respectively. There is low correlation coefficient in many cases. Hence it was impossible that the use of TOC for the water standard or monitoring instead of COD and BOD directly. However it can be used as alternative index to management a water process in the case of waste water where there was found high correlation coefficient of TOC/ COD, BOD/COD and TOC/BOD. It was sure that the water quality of river body can be protected if we use these the relationship among organic index.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.1
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• pp.200-207
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• 2019

Cement is one of the most commonly used materials in the construction and civil engineering industry. However, emissions of carbon dioxide generated during the production of cement have been linked to climate change and environment pollutants. In order to replace cement, many studies have been actively performed research to utilizing Blast Furnace Slag(BFS), which is a byproduct of the steel industry. This study aims to investigate the physiochemical properties of the BFS powder based grout to determine whether it can be used as an environment-friendly grout material. As a fine powder, BSF can be used instead of cement grout due to its potential hydraulic property. BSF has also been known for its ability to strengthen materials long-term and to densify the internal structure of concrete. In order to investigate the physicochemical properties of the BFS powder based grout as a grout material, in this study assessment tests were performed through a gel-time measurement, uniaxial compressive strength, and chemical resistance tests, and heavy-metal leaching test. Characteristics and advantages of the slag were studied by comparing slag and cement in various methods.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.477-484
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• 2019

As the residence time in the vehicle increases, the passenger desires a pleasant and stable riding environment in addition to the high driving performance of the vehicle. The windshield defrosting performance is one of the performance requirements that is essential for driver's safe driving. In order to improve the defrosting performance of the windshield of a vehicle, relevant elements such as the shape of the defrost nozzle should be appropriately designed. In this paper, CFD based numerical analysis is conducted to improve defrost performance of small electric vehicles. The defrost performance analysis was performed by changing the angle of the defrost nozzle and the guide vane that spray hot air to the windshield of the vehicle. Numerical simulation results show that the defrosting performance is best when the defrost nozzle angle is $70^{\circ}$ and the guide vane installation angle is $60^{\circ}$. Based on the analytical results, the defrosting experiment was performed by fabricating the defrost nozzle and the guide vane. As a result of the experiment, it is confirmed that the frost of windshield is removed by 80% within 20 minutes, and it is judged that the defrost performance satisfying the FVMSS 103 specification is secured.