• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.15 no.1
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• pp.15-26
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• 2017

Cobalt ferrocyanide (CoFC) or nickel ferrocyanide (NiFC) magnetic nanoparticles (MNPs) were fabricated for efficient removal of radioactive cesium, followed by rapid magnetic separation of the absorbent from contaminated water. The $Fe_3O_4$ nanoparticles, synthesized using a co-precipitation method, were coated with succinic acid (SA) to immobilize the Co or Ni ions through metal coordination to carboxyl groups in the SA. CoFC or NiFC was subsequently formed on the surfaces of the MNPs as Co or Ni ions coordinated with the hexacyanoferrate ions. The CoFC-MNPs and NiFC-MNPs possess good saturation magnetization values ($43.2emu{\cdot}g^{-1}$ for the CoFC-MNPs, and $47.7emu{\cdot}g^{-1}$ for the NiFC-MNPs). The fabricated CoFC-MNPs and NiFC-MNPs were characterized by XRD, FT-IR, TEM, and DLS. The adsorption capability of the CoFC-MNPs and NiFC-MNPs in removing cesium ions from water was also investigated. Batch experiments revealed that the maximum adsorption capacity values were $15.63mg{\cdot}g^{-1}$ (CoFC-MNPs) and $12.11mg{\cdot}g^{-1}$ (NiFC-MNPs). Langmuir/Freundlich adsorption isotherm equations were used to fit the experimental data and evaluate the adsorption process. The CoFC-MNPs and NiFC-MNPs exhibited a removal efficiency exceeding 99.09% for radioactive cesium from $^{137}Cs$ solution ($18-21Bq{\cdot}g^{-1}$). The adsorbent selectively adsorbed $^{137}Cs$, even in the presence of competing cations.

• The KIPS Transactions:PartD
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• v.12D no.3 s.99
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• pp.417-428
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• 2005

Today, IT organizations perform projects with vision related to marketing and financial profit. The objective of realizing the vision is to improve the project performing ability in terms of QCD. Organizations have made a lot of efforts to achieve this objective through process improvement. Large companies such as IBM, Ford, and GE have made over $80\%$ of success through business process re-engineering using information technology instead of business improvement effect by computers. It is important to collect, analyze and manage the data on performed projects to achieve the objective, but quantitative measurement is difficult as software is invisible and the effect and efficiency caused by process change are not visibly identified. Therefore, it is not easy to extract the strategy of improvement. This paper measures and analyzes the project performance, focusing on organizations' external effectiveness and internal efficiency (Qualify, Delivery, Cycle time, and Waste). Based on the measured project performance scores, an OT (Opportunity Tree) model was designed for optimizing the project performance. The process of design is as follows. First, meta data are derived from projects and analyzed by quantitative GQM(Goal-Question-Metric) questionnaire. Then, the project performance model is designed with the data obtained from the quantitative GQM questionnaire and organization's performance score for each area is calculated. The value is revised by integrating the measured scores by area vision weights from all stakeholders (CEO, middle-class managers, developer, investor, and custom). Through this, routes for improvement are presented and an optimized improvement method is suggested. Existing methods to improve software process have been highly effective in division of processes' but somewhat unsatisfactory in structural function to develop and systemically manage strategies by applying the processes to Projects. The proposed OT model provides a solution to this problem. The OT model is useful to provide an optimal improvement method in line with organization's goals and can reduce risks which may occur in the course of improving process if it is applied with proposed methods. In addition, satisfaction about the improvement strategy can be improved by obtaining input about vision weight from all stakeholders through the qualitative questionnaire and by reflecting it to the calculation. The OT is also useful to optimize the expansion of market and financial performance by controlling the ability of Quality, Delivery, Cycle time, and Waste.

• Journal of the Mineralogical Society of Korea
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• v.21 no.4
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• pp.341-347
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• 2008

The feasibility of commercializing the hydrothermal synthesis of Na-A type zeolite from siliceous mudstone has been conducted using a 50-liter bench-scale autoclave and the application of the zeolite as an environmental remediation agent. Siliceous mudstone, which is widely distributed around the Pohang area, was adopted as a precursor. The siliceous mudstone is favorable for the synthesis of zeolite because it contains 70.7% $SiO_2$ and 10.0% $Al_2O_3$, which are major ingredient of zeolite formation. The synthesis of zeolite was carried out under the following conditions that had been obtained from the previous laboratory-scale tests: 10hr reaction time, $80^{\circ}C$ reaction temperature, $Na_2O/SiO_2$ ratio = 0.6, $SiO_2/Al_2O_3$ ratio = 2.0 and $H_2O/Na_2O$ ratio= 98.6. The crystallinity and morphology of the zeolite formed were similar to those obtained from the laboratory-scale tests. The recovery and cation exchange ion capacity were 95% and 215 cmol/kg, respectively, which are slightly higher than those obtained in laboratory scale tests. To examine the feasibility of the zeolite as an environmental remediation agent, experiments for heavy metal adsorption to zeolite were conducted. Its removal efficiencies of heavy metals in simulated waste solutions decreased in the following sequences: Pb > Cd > Cu = Zn > Mn. In a solution of 1500 mg/L total impurity metals, the removal efficiencies for these impurity metals were near completion (> 99%) except for Mn whose efficiency was 98%. Therefore, the synthetic Na-A type zeolite was proven to be a strong absorbent effective for removing heavy metals.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.2
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• pp.100-108
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• 2000

High sodium contents in food-waste compost(FWC) is the greatest limitation to recycle it to arable lands in Korea. The effects of the FWC application to paddy soil on the growth of rice plants, cationic balance in plants, and the sodicity of soil have been studied in pot trials. The effects of FWC application were compared with those of NaCl compound and swine manure compost(SMC) application. $Na_2O$ contents of FWC were high as 2.2%. Immediately after transplanting, rice plants in three treatments showed severe wilting in the order of 40Mg FWC $ha^{-1}$ > NPK+900kg $NaClha^{-1}$ > 20Mg FWC $ha^{-1}$. The high EC value and volatile acid contents of soil solution were regarded as the cause of severe wilting of young rice plants. Increase of NaCl application rate upto $900kgha^{-1}$ showed no significant reduction of dry matter yield at harvesting stage. Regardless of application rates FWC reduced the dry matter yield at harvesting stage, while SMC increased it with increase of application rates upto $40Mgha^{-1}$. In NPK+NaCl and FWC treatments, Na contents and equivalent ratio in plants increased linearly with increase of Na application rates. Between Na and K equivalent ratio negative correlation with high significance was shown. In contrast to much difference of Na, K, and Na/K equivalent ratio among treatments, little difference of Na+K indicated the physiological substitution of Na for K in rice plants. Na use efficiency in NPK+NaCl and FWC treatments showed 12-22%.

• Applied Chemistry for Engineering
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• v.21 no.1
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• pp.52-57
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• 2010

Although chemical sedimentation and ion exchange are usually applied to the treatment of heavy metal ions and radioactive cations, they have some serious disadvantages like a great consumption of chemicals, the disposal of valuable metals, and the secondary pollution of soil by the solid-waste. The advanced countries recently have studied the electrochemical ion exchange, combined electrochemical reduction and ion exchange, for the development of the alternative technique. This study has been performed to investigate the optimum condition for the preparation of the nickel hexacyanoferrate (NiHCNFe) which is an electrochemical ion exchanger. NiHCNFe film was deposited on the surface of nickel plate by chemical method or electrochemical method. The morphology and composition of NiHCNFe were observed by SEM and EDS, respectively. The peak current density of NiHCNFe was measured from the cyclic voltammograms of the continuous oxidation-reduction reaction in a parallel plane ion exchange electrode reactor. It was found that the chemical preparation method was better than the electrochemical method. The concentrated NiHCNFe was apparently deposited on nickel plate when dipping in the preparing solution for 118 h, especially. It also had a best durable performance as an ion exchange electrode.

• Journal of Information Technology Application
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• v.2 no.1
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• pp.55-81
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• 2000

An Electronic Document Management System(EDMS) is an electronic system solution that is used to create, capture, distribute, edit, store and manage documents and related structured data repositories throughout an organization. Recently, documents of any type, such as text, images, and video files, and structured databases can be controlled and managed by an office automation system and an EDMS. Thus, many organizations are already using these information technologies to reduce process cycle-times. But what the organizations are missing is a integrated system the current workflow or office automation system and provides immediate access to and automatic routing of the organization's mission-critical information. This study tried to find out the user's requirements for integrating current information system and relatively new technology, electronic document management system in order to improve business operations, productivity and quality, and reduces waste. integration of electronic document management system(EDMS) and office automation system and proper use of these technological will improve organization's processes, and compress the process cycle-times. For this study a case study was done by a project team in cooperation with a government organization(say A company). Through this case study valuable electronic document management and office automation system requirement have been identified and reported for providing a system model in order to design an Integrated EDMS(IMDMS).

• Clean Technology
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• v.12 no.1
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• pp.37-44
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• 2006

The effectiveness of inorganic oxides (DT-30), anionic exchange resin (DT-60) and carbon absorbent (DT-80, DT-90) on the equilibrium and continuous separation characteristics and removal of cobalt, cesium and iodide ion in the waste water was investigated. As a result, DT-30, DT-80 or DT-90, and DT-60 showed excellent separation properties on the cesium, cobalt and iodide respectively. In the equilibrium experiment, the adsorption amount of cesium for DT-30 increased with temperature, but increasd largely with pH. In case of DT-80, adsorption of cobalt was depended on pH but was not influenced by temperature. In the continuous system by passing a heavy metal ion solution through the ion exchange tower, DT-30, DT-90 and DT-60 showed good separation characteristic for cesium, cobalt and iodide respectively. In this case, separation characterization of DT-30 on the cesium and of DT-60 on the iodide were better than that of DT-90 on the cobalt. From the experiment on the effect of impurities on the ion exchange characteristics, impurities such as surfactant and oil did not influence the efficiency of DT-90. In the mean while, ion separation capacity of DT-30 were decreased largely by impurities such as surfactant and oil. Also, surfactant had a strong influence on the effectiveness of DT-60. Accordingly, it turned out to be very important thing that impurities should be removed in the preprocessing stage.

• Journal of the Korean Chemical Society
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• v.56 no.2
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• pp.228-235
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• 2012

A $N_2O_2$ Schiff base ligand, N,N'-bis(4-methoxysalicylidene)phenylendiamine (4-$CH_3O$-salphen) was synthesized. Using the 4-$CH_3O$-salphen, the spectrophoto-metric quantitative analysis of Cu(II) ion in aqueous solution was performed. The optimum condition for the quantitative analysis of Cu(II) ion was determined as the following; the concentration of 4-$CH_3O$-salphen is $2.0{\times}10^{-4}\;mol/L$, ratio between solvent DMSO and water is 50/50(v/v), pH is 5.5. After 1 hr water incubation at $55^{\circ}C$ and then the absorbance measurements at 388 nm, a calibration curve (${\varepsilon}=3.6{\times}10^4\;mol^{-1}cm^{-1}$) with a correlation coefficient ($R^2$=0.9963) was obtained in this condition. Using this optimized condition, the quantitative analysis of Cu(II) ion was performed with various samples such as hot spring water, semiconductor factory waste water and treated water from sewage treatment plant. The average value of the measured values agreed well with standard value with a range of 0.6~5.4%. The limit of determination was 31.77 ng/mL ($5.0{\times}10^{-7}\;mol/L$).

• Journal of the Korean Applied Science and Technology
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• v.33 no.3
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• pp.441-448
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• 2016

Heavy metal removal study is conducted from synthetic waste water by reduction and oxidation(redox) reaction of Cu-Zn metal alloy and adsorption reaction of aluminium silicate. Heavy metal whose ionization tendency is smaller than zinc are reducted in an aqueous solution, and the concentration of ionized zinc is reduced by adsorption reaction. The average diameter of metal alloy micro fiber is about $200{\mu}m$, and the surface area is wide enough to get equilibrium in a single cycle treatment. A single cycle treatment of redox reaction of Cu-Zn metal alloy, could remove 100.0 % of Cr(III), 98.0 % of Hg, 92.0 % of Sn and 91.4 % of Cu respectively. An ionization tendency of chromium is very close to zinc, but removal efficiency of chromium by redox reaction is significant. This result shows that trivalent chromium ion is expected to generate hydroxide precipitation with $OH^-$ ion generated by redox reaction. Zinc ion generated by redox reaction is readily removed by adsorption reaction of aluminium silicate in a single cycle treatment. Other heavy metal components which are not perfectly removed by redox reaction also showed very high removal efficiency of 98.0 % or more by adsorption reaction. Aluminium ion is not increased by adsorption reaction of aluminium silicate. That means heavy metal ion removal mechanism by adsorption reaction is turned out to be not an ion exchange reaction, but an adsorption reaction.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.53-61
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• 1997

This study was conducted to analysis citizen's attitude and style to the foodwaste from l0th Sept. to 30th Sept. in 1996. The research was used questionare method and analysis was used prequency analysis and cross table method by SPSS (scientific statistics). The foodwaste of householdwaste account for 24.8%, and the magnitude by the kinds of garbage were waste from pre-cocking stage, fruitshell, foodwaste remained after eating, septic foodwaste during storage. The more the housewives'age are young, foodwaste volumne were much. Most remained foodwaste after eating were soup and pot stew. The main cause of foodwaste production was overvolumne cooking. 88.8% of answers think that a menu can be useful to reduce foodwaste. The survey showed that 87.3% of answers put into the meter-rate bag after removed wetness of garbage. 84.1% of answers thought that the recycling of foodwaste needed, but the practical housewife was only 21%. For the suitable treatment of foodwaste, Survey showed that the consistent policy of goverment and continuous publicity was needed essentially, and that the public notice of TV or radio was effective. All of answers would like to participate in recycling of foodwastes whether public-posting or personal-posting. To set up vessel of posting at household, the proper purchase price and space of institution are needed, also the solution of sanitory & aesthetic problem and the collection of composting-product must be achieved smoothly.