• Journal of Korea Society of Waste Management
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• v.35 no.8
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• pp.721-730
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• 2018

We investigated the effects of heavy metals in cement in the last 3 years and the amount of waste in the cement manufacturing process. The result shows that the average $Cr^{6+}$ content in cement products is controlled at 10 mg/kg. Cu and Pb have lower detection tendency in white cement than in ordinary portland cement. In addition, heavy metals such as Cd show a certain level of detection regardless of the input wastes. Copper slag and phosphate gypsum are the main influencing factors on the heavy metals in cement products. In auxiliary fuels, plastics waste and wood waste are considered to affect heavy metals in cement products. Alternative raw materials are considered to be affected by the alternative raw materials managed as byproducts. In the case of supplementary fuels, auxiliary fuels managed as waste instead of auxiliary fuels managed as byproducts affect the heavy metals in cement. This study examined the input amount without considering the heavy metals in each waste. Therefore, the result may vary in different situations, and further research must be conducted to supplement the findings. However, if the heavy-metal contents in the waste are constant, it can be used as a reference material for the control of heavy metals in cement products.

• Journal of Environmental Health Sciences
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• v.35 no.3
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• pp.226-234
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• 2009

The main objective of this study was to evaluate the effects on shape and size, compressive strength, water absorption and heavy metals leaching with various weight mixing ratios in waste ash brick products using waste recycling MSWI(Municipal Solid Waste Incinerator) bottom ash, steel slag and waste building material. The manufacturing processes for the waste ash brick consist of screening, mixing, conveyor transmission, compaction.forming, and curing steps of raw materials. The weight mixing ratios of steel slag around bottom ash were adjusted within the ranges of 10% to 30%. The reported results show that the width and thickness of the manufactured waste ash brick could be satisfied with $90{\pm}2mm\;and\;57{\pm}2mm$, respectively which are K.S. standards of products qualities. And in case of length, only 20-Ba50Ss30, 20-Ba60Wb20 and 20-Ba50Wb30 for the mixing ratios could be satisfied with $190{\pm}2mm$ that is K.S. standards of products quality. The compressive strength and water absorption for 20-Ba50Ss30 and 20-Ba70Wb10 were over $8N/mm^2$ and below 15% respectively that are K.S. standards of manufactured waste ash brick. The results of tests for the heavy metals leaching in the all manufactured waste ash bricks are also passed to the wastes management regulations. The cost analysis of 20-Ba50Ss30 is evaluated. The manufacturing cost is evaluated 34.3 won/brick with 8 hours and 20tons of raw material per day. Incinerators with problems in bottom ash disposal can therefore derive significant benefits from the application of waste ash brick production.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.440-448
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• 2002

Waste glass has been increased with the development of industry. The utilization of waste glass for concrete can cause the concrete to be cracked and to be weakened due to an expansion by alkali-silica reaction(ASR). In this study, ASR expansion and properties of strength were analyzed in terms of waste glass color(amber, emerald-green), industrial by-products(ground granulated blast-furnace slag, fly ash), and the content of industrial by-products for reducing ASR expansion caused by the waste glass. The possibility of using glass ground as pozzolanic properties was also analyzed. From the result of this study, the pessimum size of waste glass was 2.5∼1.2 mm regardless of waste glass color. And the smaller than 2.5∼1.2 mm waste glass is, the more decreasing expansion of ASR is. Also, the combination of waste glass with industrial by-products have an effect on reducing the expansion and strength loss caused by ASR between the alkali in the cement paste and the silica in the waste glass, and the glass ground of less than 0.075 mm is applicable as a pozzolanic material.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.2
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• pp.77-86
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• 2001

As construction and expansion of wastewater treatment works is continuing, generation of sludge is increasing. Bur most sludge is not used appropriately but disposed by landfill dumping to sea. Furthermore direct landfilling of sludge cake containing moisture content over 75% has been legally prohibited since 2001 that's enforcement will be more strict in 2003. Such a situation means nowadays recycling of organic waste such as sludge and food waste is necessary. Composting is one of recycling methods commonly and used as an effective means of stabilizing organic waste and then compost can be used as fertilizer. However fertilizer law management which include standard of compost products and other fertilizers applied all sludge products indiscriminiately and was not flexible. So MOE has graded organic composts according to land applications to improve recycle of organic wastes. The classified organic compost which contains low contaminants has been possible to use as various purpose. This study enalyzed 30 samples which were raw materials for compost and compost products management well and to estimate the quality of compost products. Heavy metals were measured in Raw materials and OM/N, NaCl and VS were tested in compost products as well as heavy metals. As a result, approximate 10% of raw materials was not suitable to the grade A and 6.7% over the grade B of the regulation on raw materials for compost. In the case of 30 produced compost propducts approximate, 57% of composts was not compatible with the grade A and B of the regulation on composting product. The qualities of compost products were worse than raw materials, because the compost products have more regulation item raw materials have.

• Journal of the East Asian Society of Dietary Life
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• v.6 no.3
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• pp.381-391
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• 1996

The main purpose of this study is to investigate the effect of housewives' dietary awareness and habits on the reduction and recycling of food waste products. We have done statistical analyses of 501 questionnaires answered by housewives living in Taegu city. The results are as follows: The dietary awareness is significantly different according to the housewives' ages. The group of above 50's age and the group of housewives and their husbands with a lower education level have a more traditional awareness and eating up habits. Also the younger group, and those with a higher education level who grew up in a big city have a more progressive dietary awareness. But the younger, higher income, small family, higher education level groups, and also employed housewives, produced more food waste products than the other groups, The groups thsose have traditional or rational awareness concerning dietary awareness, and those with good eating up and accurate cooking habits turned out to have more affirmative effects on the reduction and recycling of food waste products.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2020.11a
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• pp.167-168
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• 2020

In order to expand the material recycling of waste plastics made of composite materials, it is necessary to develop the use of material recycling products and to secure their quality stability. In this paper, as a basic study to secure the stability of the quality of household waste plastic material recycling products, the quality characteristics of recycled materials according to the production period were compared and reviewed. In addition, the average tensile strength of the recycled products by production period for 4 months was 12.33 MPa, and the average density was 1.35 g/m3.

• Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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• 2008.04a
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• pp.222-228
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• 2008

The chemical composition and thermal, crystal characterization of oak mushroom waste were investigated in comparison with those normal oak wood for utilization of cellulose from oak mushroom waste. The oak mushroom waste contained a higher percentage of ash, and hot water extractives than oak wood. This results indicated that the materials inside the body are easily decomposed during the oak mushroom cultivation. The lower percentage of holocellulose and a-cellulose of oak mushroom waste caused by fungal decomposition too. Whereas, the thermal decomposition behavior and crystallinity of oak mushroom waste was similar to that of normal oak wood, which indicated that the cellulose characterization of oak mushroom waste is resistant to fungal decomposition. In additionally, a degree of polymerization of oak mushroom waste must be investigate for examination of cellulose crystalline characterization, especially.

• Design & Manufacturing
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• v.16 no.4
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• pp.60-66
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• 2022

Recently, with the development of industry and the improvement of living standards, various wastes are generated along with the production of various products. Most of these wastes are used as containers for products, and plastic or aluminum is used. Various attempts are being made to automate the classification of these wastes due to the high labor cost, but most of them are solved by manpower due to the geometrical shape change due to the nature of the waste. In this study, in order to automate the waste sorting task, Deep Learning technology is applied to a robot system for waste sorting and a vision system for waste sorting to effectively perform sorting tasks according to the shape of waste. As a result of the experiment, a Deep Learning parameter suitable for waste sorting was selected. In addition, through various experiments, it was confirmed that 99% of wastes could be selected in individual & group image learning. It is expected that this will enable automation of the waste sorting operation.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.281-285
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• 2001

This technology Provides an economical Production of high value added goods applicable to electro chemicals by recycling of waste products in EGL(Electro Galvanizing Line). The waste products produced in EGL contain potassium chloride (KCI), nickel and zinc. Highly pure KCI and Zinc Chloride which are raw material of electro plating, can be produced by the development of the recycling process. The scope of this study ranges from laboratory experiments to pilot test in plant. We have developed the whole process of recycling technology such as purification method of waste products, fabrication methods of electro chemicals, basic design of plant, pilot scale production and evaluation of pilot goods, Developed electro chemicals were pure enough to satisfy the specification of steel company.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.05a
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• pp.191-192
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• 2016

Recently, there have been many studies about recycling cementitious powder from concrete waste, generated after recycle aggregate production. Previous studies showed that when the heating process of waste powder in paste is dehydrated making possible the restoration of hydraulic properties. Thus the purpose of this study is to make an experimental review on properties of concrete products made vibration-compressive according to waste concrete powder.