• Environmental Engineering Research
• /
• v.10 no.1
• /
• pp.1-6
• /
• 2005

Hexavalent chromium in aqueous solutions was successfully removed via sorption and reduction in the presence of waste leaves. Cr(VI) removal followed a first-order reaction, and removal rates were proportional to the amount of waste leaves used in the tests. Most of Cr(VI) were removed via sorption in early stages of the tests, but the reduction reaction played a significant role in Cr(VI) removal later. Solution pHs were continuously decreased due to the microbial activity, which was induced from the microorganisms attached on waste leaves. The decreased solution pHs further enhanced the sorption and reduction of Cr(VI). To characterize the microorganisms found in the tests, a denaturing gradient gel electrophoresis (DGGE) method was used. The majority of microorganisms were composed of Bacillus sp. which can reduce Cr(VI). Thus, waste leaves can be effective reactive media for the treatment of Cr(VI) in the subsurface.

• Journal of Families and Better Life
• /
• v.16 no.4
• /
• pp.197-220
• /
• 1998

This study is conducted to examine the ways to reduce the garbage amount by effective recycling food wastes in the cooking. The data is collected from 864 housewives who live in Seoul/Sungnam/Choongju by using questionnaires from 24 November 1997 to 5 January 1998. The results are as follows; The level of their needs of reusing food wastes in the cooking is high but the level of their participation and its satisfaction to reuse housewives is low. Especially they take part in reusing the garbage in pre-treatment less than edibile plate wastes. These factors result from lacking of their consciousness and knowledge of methods to reuse food wastes. Therefore it is said that consumer should make an effort themselves to participate in reusing food waste researcher should search the way to efficiently reuse the food waste and government should found the policy to provide information and education program for reusing food waste. The more seriously they perceive food waste reuse the mo e they want the way to accelerate food waste reuse by consumer researcher and government.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10b
• /
• pp.1248-1251
• /
• 2000

Recently, the yearly amount of remicon used in Korea is approximately one hundred million cubic meter, and it caused a by-product, remicon waste sludge. The sludge produced by washing mixers or drums of remicon trucks is restrained by the law for waste disposal because its pH is over 12, so the expense for waste disposal is needed. Until now, the waste sludge water has been recycled and used for concrete materials as sludge water which is limited to 3% of cement unit weight. However, the study on the properties of the concrete mixed with this waste sludge is so insufficient that the quality of them can be hardly trusted. Therefore, the study on that will be discussed.

• Nuclear Engineering and Technology
• /
• v.53 no.6
• /
• pp.2011-2018
• /
• 2021

Nowadays, evaluation of amounts and distributions of radioactive waste is an important preparatory step in the process of nuclear reactor decommissioning. For tentative estimation of radioactive waste, a cell-based rigorous 2 step (R2S) method usually is used; however, a poor resolution caused by the averaged flux and spectrum in a cell is still a great challenge because of leading to underestimated or overestimated results. To overcome the poor resolution, several systems were introduced. Neither system, however, provides any function for evaluation of radioactive waste amount and distribution. Thus, it is additionally required to classify radioactive waste based on the results of activation calculation. In this study, the advanced R2S (AR2S) system was developed. To verify the performance of the system, its results for a verification problem were compared with those of the cell-based R2S method. The results showed good agreement, which is to say, within 2.0% relative error. Also, several characteristics of fine/coarse mesh were analyzed. To demonstrate the performance of the AR2S system, the radioactive waste from the Japan Power Demonstration Reactor (JPDR) was estimated, and the result indicated a high-resolution distribution. Therefore, it is expected that the AR2S system will prove useful for precise evaluation of radioactive waste.

• Proceedings of the Korean Radioactive Waste Society Conference
• /
• 2003.11a
• /
• pp.32-37
• /
• 2003

The amount of 4,500 drums of soil waste are temporarily stored in KAERI. In order to develop a technology for safe treatment of the soil waste, a number of tests were performed by applying cement and polymer as solidifier. Immobilization specimens were adequately made by mixing soil waste with cement or polymer Compressive strength and leaching tests were performed in order to see the fulfillment to standard of disposal following the storage. A compressive strength, about 5,300psi was obtained from both solidifiers of cement containing 40% of soil waste and polymer containing 60%. The obtained leaching index was larger than 11, which was satisfied with the relevant standard. It was shown that the integrity of the solidified waste much depends on homogenization in solidifying process and hardness of the specimen. Volume reduction of solidified waste with polymer was better than that of cement by 20%.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.8 no.1
• /
• pp.41-48
• /
• 2013

Waste Stone and Waste Stone Powder are recycling some cyclic aggregate only. And the greater part of Waste Stone and Waste Stone Powder are reclaining or neglecting. To solve this problem, the government is proceeding development of cementitious scagliola using waste stone and waste stone powder. However, quality standard for cementitious scagliola using waste stone and waste stone powder has not been established. So cementitious scagliola using waste stone and waste stone powder has problem of quality assurance. Therefore in this study, developed standard for Evaluating Performance of cementitious scagliola using waste stone and waste stone powder through survey of international standard.

• Industrial Engineering and Management Systems
• /
• v.10 no.2
• /
• pp.115-122
• /
• 2011

This research considers a system containing a manufacturing firm who generates waste material during manufacturing process, and a disposal firm who collects and disposes the waste material. Identification of the optimal number of pick ups and the amount of waste to be disposed at certain period of time in terms of cost minimization is studied. Two types of waste accumulation rates, constant and linearly increasing, are discussed and mathematical models are developed. It can be shown that the results for these two different types of waste accumulation differ in a wide range because of the difference in the way of how waste is accumulated, which disturbs the storage cost. An integrated model is also developed and discussed in which both the manufacturing firm and the disposal firm benefit from the coordination between the two parties. It is shown that the optimal policy adopted by the integrated approach can provide a strong and consistent cost-minimizing effect for both the manufacturing firm and the disposal firm over the existing approach. Finally, all the models are verified by a numerical example and the results are compared.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.53 no.6
• /
• pp.59-65
• /
• 2011

This study was performed to evaluate the compressive and flexural strength, void ratio and permeability coefficient used powdered waste glass, $CaCO_3$, recycled coarse aggregate and unsaturated polyester resin to find optimum mix design of permeable polymer concrete for pavement. The compressive and flexural strength of permeable polymer concrete for pavement using powdered waste glass were in the range of 16.8~19.7 MPa and 4.7~6.1 MPa, respectively. it was satisfied the regulation of permeable concrete for pavement (18 MPa and 4.5 MPa). The void ratio and permeability coefficient were decreased with increasing the powdered waste glass, respectively. The void ratio and permeability coefficient were satisfied national regulation of permeable concrete for pavement (8 % and $1{\times}10^{-2}$ cm/s). In addition, this study found out that required amount of binder was decreased with increasing the powdered waste glass. This fact is expected to have economical effects during the use of powdered waste glass in the manufacture of permeable polymer concrete for pavement. Accodingly, the powdered waste glass can be used for permeable concrete material.

• Korean Journal of Agricultural Science
• /
• v.38 no.1
• /
• pp.145-151
• /
• 2011

This study was performed to evaluate the void ratio, compressive and flexural strength, and permeability coefficient used powdered waste glass, $CaCO_3$, recycled coarse aggregate and unsaturated polyester resin to find optimum mix design of permeable polymer concrete for pavement. The void ratio and permeability coefficient of permeable concrete for pavement was decreased with increasing the powdered waste glass, respectively. The compressive strength and flexural strength was increased with increasing the powdered waste glass, respectively. In addition, this study found out that required amount of binder was decreased with increasing the powdered waste glass. This fact is expected to have economical effects during the use of powdered waste glass in the manufacture of permeable polymer concrete for pavement. Therefore, powdered waste glass and recycled coarse aggregate can be used for permeable polymer pavement.

• Journal of Environmental Science International
• /
• v.19 no.2
• /
• pp.255-260
• /
• 2010

A stabilization/solidification (S/S) process for lead (Pb) contaminated soils was evaluated using waste cow bone containing apatite like compounds. Soil samples obtained form firing range were treated with waste cow bone. The effectiveness of stabilization was evaluated based on the Korean Standard Leaching Test (KSLT) and soil pH. The leached concentration reduced with increased in dose of waste cow bone. Overall, the KSLT results showed that Pb concentration in soils are significantly affected by amount of waste cow bone. When soil amended with 20 % of waste cow bone, less than 0.1 mg/kg was leached, and soil pH was increased from 6.5 to 8.4. Same results were obtained when finer waste cow bone was applied. The reachable concentration of Pb in soil showed in inversely proportional to solid/liquid ratio. Aging periods indicate improving mix design was applied. Relatively high lead concentrations was observed at the first 1 days, however leaching profile are reduced significantly over time for all mix designs.