• Journal of the Korea Institute of Building Construction
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• v.20 no.5
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• pp.391-397
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• 2020

This study is to compare and analyze the strength, drying shrinkage and carbonation properties of lightweight aggregate mortar using recycling water as prewetting water and mixing water. The flow, compressive strength, split tensile strength, drying shrinkage and carbonation depth of lightweight aggregate mortar with recycling water were measured. As test results, the mortar flow was similar in all mixes regardless of the recycling water content. The compresseive strength of the RW5 mix with 5% recycling water as prewetting water and mixing water was the highest value, about 53.9 MPa after 28 days. In addition, the tensile strength of lightweight mortar was about 3.4 to 3.8 MPa, indicating 7 to 9% of the compressive strength value regardless of recycling water content. In the case of drying shrinkage, the RW2.5 mix using 2.5% recycling water showed the lowest shrinkage rate as about 0.107% at 56 days. The drying shrinkage of the plain mix without recycling water was relatively higher than the RW2.5 and RW5 mix. The RW5 mix showed lowest carbonation depth compared to other mixes. In this study, the RW5 lightweight aggregate mortar with 5% recycling water exhibits excellent compressive strength and carbonation resistance. Therefore, it is considered that if the recycling water, a by-product of the concrete industry, is properly used as prewetting water and mixing water of lightweight mortar and concrete, it will be possible to increase the recycling rate of the by-product and contribute to improve the property of lightweitht aggregate mortar and concrete.

• Korean Management Science Review
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• v.31 no.1
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• pp.1-15
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• 2014

As the scarcity of natural resources has become apparent, the recycling industry has emerged as a promising one for its growth potential. Yet, the recycling industry still remains undeveloped and inefficient for various reasons. In this study, we focus on firms' recycling processes to understand the current status of recycling firms' value creation activities. With respect to the adopted recycling processes, we empirically investigate the differences in firm characteristics and firm performance. We use the data from Keco (Korea Environment Cooperation) which annually conducts a survey of recycling firms in Korea. We exclusively consider the whole group of plastic recycling industry in order to control for a possible bias in firm performance, stemming from the heterogeneity in processing and recycling of materials other than plastics. We review the descriptive statistics from the sample firms and conduct a series of hierarchical regression analyses. The results show that most of the firms in this industry adopt physical transformation processes with a low-level technology. These firms with physical transformation processes are smaller in size and produce entry level items which do not secure higher margins. The results indicate that the recycling industry largely comprises low value added firms which lack economies of scale and resources for R&D. For the stable growth of the industry, recycling firms must create sustainable values through implementation of technology-driven processes and improvement in product quality. In addition, the government should help build a reliable reverse logistic network, lower the entry barriers, and provide necessary funding for the SMEs in the recycling industry.

• 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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• 2019.11a
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• pp.153-154
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• 2019

In this study, the fluidity and compressive strength of lightweight mortar using recycling water for pre-wetting of artificial lightweight aggregate were compared and analyzed to maximize the utilization of the recycling water, which is a by-product of the Ready-Mixed Concrete industry. For this purpose, the pre-wetting water was replaced with recycling water at the ratio of 0, 2.5, 5, 7.5 and 10%.

• Industry Promotion Research
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• v.1 no.1
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• pp.137-142
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• 2016

This study verified the effect of the perception of water reuse on water reuse practice intention. The study results showed that the perception of water reuse practice necessity, the effect of water recycling toilet(p<.01), compulsory installation of water recycling product in public institution, expansion of compulsory installation of water recycling product, the law of water reuse promotion and support(p<.05). Also, monthly household income, occupation and monthly water rate significantly affected the between-group differences of water reuse practice intention. This study provided implications for operating water reuse policy by analyzing the effect of the perception of water reuse on water reuse practice intention to enhance water reuse practice.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.105-112
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• 2005

This study aims at evaluating the environmental impacts stemmed from the End-of-Life Vehicle(ELV) treatment systems in Korea, using Life Cycle Assessment(LCA) method. In this study, both environmental burden from the ELV dismantling process & recycling processes and environmental benefit which were derived from the avoided environmental impacts by substituting recycled materials for virgin materials were considered. First of all, the key issues which were defined as the environmental aspects that account for more than $1\%$ out of the total environmental impacts were identified from the Life Cycle Impact Assessment(LCIA). $CO_2$, crude oil, natural gas, coal, etc. were found out to be the key issue parameters. From the LCI Analysis and LCIA studies, it was shown that the significant environmental aspects were related with the recycling process of ferro scrap, the shredding process of compressed car bodies and the dismantling process of end-of-life engines. In particular, the recycling process of ferro scrap has the most significant effects on the environmental impacts of the ELV treatment systems. Based on these results, it is recommended to improve the recycling process of ferro scrap in order to make the ELV treatment systems more environmentally sound.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.19-23
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• 2001

In addition to landfilling and incineration, waste minimization and recycling have become priorities in Taiwan's municipal waste management strategies over the past 10 years. Major recycling initiatives being implemented in Taiwan include producer responsibility, "pay-as-you-throw, " and mandatory sorting provisions. Currently, the producer responsibility regime established under the Waste Disposal Act and administered by the Environmental Protection Administration (EPA) requires that manufacturers or importers of listed items, including containers, batteries. cars, motorcycles ("scooters"), tires, oil, televisions, refrigerators, air conditioners, washing machines, computers, and printers, pay recycling fees to government recycling funds. EPA then uses the recycling funds to subsidize collection and recycling. The 2001 recycling fund budget totals NT$57 billion (NT$35 = US$l). Under the producer responsibility regime, EPA-designated retailers ("sellers") must accept end-of-life items returned to them by the consumers. At the local level, Taipei City implements a pay-as-you-throw program, whereby citizens pay waste collection and treatment fees through the purchase of special trash bags approved by the Taipei City Government. However. recyclables that are separated by citizens are collected free-of-charge by the City. Taichung City and Kaohsiung City, on the other hand, enforce mandatory sorting schemes, whereby citizens face penalties if they don't separate recyclables from the trash before pick-up. These programs have resulted in a significant reduction in municipal waste. Per capita waste collected per day has dropped from 1.143 kg in 1997 to 0.978 kg in 2000. Targeting a 10% recycling rate for municipal waste in 2001. EPA plans to research and develop new recycling techniques, expand the scope of producer responsibilities, and strengthen existing municipal recyclable collection programs. To this end, among other initiatives, EPA has prepared a draft "Resource Recycling and Reuse Act" that would complement the existing producer responsibility programs by incorporating into the current recycling framework the concept of product life-cycle management.

• Magazine of RCR
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• v.9 no.3
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• pp.13-16
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• 2014

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.2
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• pp.57-64
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• 1997

This study was performed to investigate the characteristics of compost produced from the composting facility at Nanjido. The capacity of the facility is 10 ton/day. Feed material was food waste generated in Seoul. Moisture content of the compost product was 31% and conductivity was 2.6 mmhos/cm. The compost product met Korean quality standards and EC quality standards for VS and C/N ratio. In case of TOC and TKN, they were met with Japan quality standards. The water soluble-C/N ratio finally reached about 5 based on dry compost. The color of compost product was dark brown. The product had earthy smell. Heavy metal contents of the compost were below Korean quality standards by wet basis.

• Resources Recycling
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• v.22 no.4
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• pp.46-54
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• 2013

The produced quantity of waste plastics including waste vinyls was assumed as about 5 million tons per year. The quantity of waste vinyls produced from the waste recycling center among total quantity of waste plastics was estimated as about 1 million tons per year. Most of waste vinyls produced from the waste recycling center were recycled as refuse plastic fuel(RPF) or recycled feedstock material. In this study, the medium material using waste vinyls was made by the melting process of heat medium heating and the tensile strength was analyzed for checking the usable possibility of recycled waste vinyl material by comparing with the existent product. In order to use the medium material for producing the recycled product, it can be considered that the tensile strength of medium material is more than 100 $kgf/cm^2$.