• Magazine of RCR
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• v.18 no.1
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• pp.34-39
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• 2023

• Resources Recycling
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• v.28 no.6
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• pp.73-78
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• 2019

In this investigation, off-gas generated from the activated sludge in wastewater treatment plant was monitored. Through monitoring, the oxygen transfer efficiency in the aeration system and the reliability was evaluated by comparing to clean water. First, the dissolved oxygen, oxygen transfer coefficient, and standard oxygen transfer efficiency were measured based on clean water, and the values were 8.60 mg/L, 9.490/hr and 23.96%, respectively. The off-gas monitoring at the wastewater treatment plant indicated that the standard oxygen transfer efficiency was 22.81%. Little difference in oxygen transfer efficiency this data inferred that the performance was improved through diffuser installation in the field monitoring system.

• 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 Korea Organic Resources Recycling Association
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• v.18 no.3
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• pp.38-49
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• 2010

The technology of anaerobic digestion of organic wastes has been researched for the production of biogas in various purposes. Biogas comes from anaerobic digestion and landfill in which that of main components are methane and carbon dioxide containing small amount of hydrogen sulfide and ammonia. Biogas can either be used directly on the site where it is generated after proper upgrading or distributed to external customer via separate pipelines like natural gas. There are four basic ways biogas can be utilized such as production of heat and steam, electricity production, vehicle fuel and production of chemicals. There is no international technical standard for biogas use but some countries have developed national standards and procedures for biogas use. In this paper, technical standards of biogas depending on purpose have reviewed for the several countries.

• Resources Recycling
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• v.10 no.5
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• pp.36-43
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• 2001

The chlorine component in fly ash from municipal solid waste incineration ash was removed by water washing for the purpose of recycling fly ash as a raw material of ordinary portland cement. The samples were a different kind of 리y ashes using $Ca(OH)_2$and NaOH as media of wet scrubber for flue gas cleaning. The content of soluble salts of fly ash using $Ca(OH)_2$and NaOH was 32.8%, 50.1% and the content of chlorine component, 22.9% and 26.0% respectively, which was KCl, NaCl, CaC1OH mainly. When each fly ash was washed using water under conditions of a agitation speed of 300 rpm, a liquid to solid ratio of 10, most soluble salts in fly ash were dissolved within 30 minutes and the content of chlorine component in ash was diminished to the content of 4.4%, 2.O% at $20^{\circ}C$ and 1.7%, 0.8% at $50^{\circ}C$ respectively. And the main compound of residual chlorine component in ash after water washing was friedel`s salt ($3CaO.A1_2$$O_3$.$CaCl_2$.$10H2$O). From analysis results of water quality for wastewater by water washing, the components exceeding discharged wastewater standard were only Pb and Cd. But As pH was controlled to 10 with addition of $CO_2$(g) or $Na_2$$_CO3$in water, the concentration of heavy metals such as Pb and Cd was also under discharged wastewater standard.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.158-165
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• 2014

The enormous quantity of 'Bayer-Process by-products' (BP by-products) discharged by industries producing alumina from bauxite represents an environmental and economical problem. As it is mainly composed of $Fe_2O_3$, $Al_2O_3$, $SiO_2$, CaO and $Na_2O$, it is thought that using BP by-products as a construction material is an effective way to consume such a large quantity of alkaline waste. In this study, This study evaluates the effect of alkali-activated binder based on recycling BP by-products on soil improvement through the evaluation of slope stability and seepage flow numerical analysis. The results of analysis of ground slope safety at dry season and wet season meet standard (Ministry of Land, Infrastructure and Transport, 2006) Especially, when wet season, the ground used soil improving material meet standard, while the ground used soil-nailing method doesn't. Also, permeability coefficient of improved soil is smaller than that of natural soil and saturation depth of reinforced ground surface with improve soil is lower than that of natural soil.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.4 no.2
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• pp.24-32
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• 1998

This study examined the effects of recycling on chemical pulp fibers from multiple recycles. Firstly, water-pretreated alkaline photocopy paper was disintegrated by TAPPI standard disintegrator at room temperature. After dewatering, this pulp was dried in oven at $80^{\circ}C$ for 24hrs. A sequence of wetting, disintegrating and drying was one recycling cycle and this cyclic treatment was repeated from zero to five times. The recycled handsheet dropped to 90% of the original brightness after five cycles, and lost the most brightness in the first two cycles. However, it had a gain of 10% in opacity after five cycles. And, in this study, the method for determining residual ink(toner) content in recycled handsheets were estabilished by means of SEM-EDX and atomic absorptive photometer. The change of residual ink percentage on recycled paper showed the effect of recycling numbers on deinkability of waste paper. A slight decrease in deinkability was noted for the recycled handsheets, which may be due to the change of fiber surface free energy connected with fiber swelling.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.425-432
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• 2021

In this paper, We produced supporting for ginseng cultivation facilities as a material recycling product of CPW(Complex Plastic Wastes, CPW) from households. And we analyzed the characteristics of material recycling products according to the amount of r-LDPE(Recycled low density polyethylene, r-LDPE) used. As a result, as the amount of recycled LDPE used increa sed, the tensile strength a nd elonga tion of ma teria l recycled products using CPW increa sed, but a sh decrea sed. When the recycled r-LDPE usage is 5% or more, the physical properties of the material recycling product using CPW stably satisfy the quality standard (GRM 3093-2021) of supporting for ginseng cultivation facilities.

• Journal of Environmental Science International
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• v.20 no.5
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• pp.631-638
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• 2011

The sense of crisis on seriousness of earth environment is gradually getting greater and the importance of environment education followed by this trend is being highlighted. As an environment friendly New Environmental Paradigm opposed to the human Dominant Social Paradigm on the existing environment is on the rise, the environment education considers not only the perceptive field, but the definitive field and behavioral pattern to follow as important values. Accordingly, the basic awareness of students on environment was found out in order to perform a proper environment education and tried to find out the behavior pattern that the students have on environment on this basis. For the research tool of this study, the one that has revised the Revised NEP Scale for elementary school students which Geum, Ji Hun Kim, Jin Mo have validated the feasibility and reliability while the test paper was prepared by dividing into recycling behavior, energy preservation behavior and source of information. The target of this study was 600 students in sixth grade of elementary school residing in Kimhae, Gyeongsangnamdo while the mean, average, standard deviation, independent t-test and correlation analysis were performed using SPSS 15.0 statistics program for a total of 462 copies including 235 copies from male students and 227 copies from female students. The results of this study are as follows. First, everyone had high pro-NEP tendencies on the environmental problem with 4.14. On the other hand, the anti-NEP did not have high awareness standard with 2.98. Second, the awareness level on resource recycling was shown as being quite high with 4.05. Between NEP and resource recycling, a positive correlation of r=.155 was shown so that the awareness level on resource recycling was getting quite high as the awareness on environment problem was getting higher. Third, the awareness level on energy saving activity was shown as being very high with 3.0. Between NEP and resource recycling, a positive correlation of r=.210 so that the awareness level on energy saving was getting quite high as the awareness on environment problem was getting higher. Fourth, for the source of information on environmental problems of region, our country and global village, the television and internet were shown as main sources of information while the ratio of positive answers on teachers and region as sources of information was shown as quite low.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.3
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• pp.127-135
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• 2001

Achieved to grasp possibility to use compost that make food waste and sawdust (bulking agent) by raw material in this research droopingly to bulking agent calamity. To be kept by aerobic experiment method to 4 composting device that air is supplied Food Waste + Sawdust, Livestock Feces + Sawdust, Food Waste + Compost, Livestock Feces + Compost free medical care and investigated composting sledding and temperature, pH, the moisture rate, heavy metals item etc. Judged that food waste of the moisture rate mix experiment result food waste input (food waste and sawdust composting done material mean) compost happened after resources anger as bulking agent food waste and Livestock Feces quantity is 72~77%, because axis dries to promote optimum composting progress appearing by 64~65%, thing which use need and was difficult to set salt 1% that is by-product compost standard when use compost as bulking agent of food waste but by dilution effect of Livestock Feces quantity using compost being expose that preservation is available by standard low because salt content density of done compost becomes found possibility that can solve salt content problem.