• Resources Recycling
• /
• v.27 no.1
• /
• pp.92-105
• /
• 2018

The present study was carried out to find a suitable drying method for measuring non-evaporable water contents of various hydraulic inorganic materials. In Part 1 of the paper, the case Ordinary Portland cement is discussed. Various drying methods including vacuum and oven drying, and an ignition, were used for the OPC paste and mortar having different w/c. The sole vacuum drying under room temperature led a fluctuation on measurement of hydration degree, while the sole oven drying also yielded unwanted hydration promotion at the early age. A combination of the vacuum and oven drying was considered as a suitable drying method for the OPC case.

• Spatial Information Research
• /
• v.19 no.5
• /
• pp.53-62
• /
• 2011

Recently environmental pollution and resource depletion have been rapidly progressing in the world. Construction Industries discharge tones of wastes and consumes heavy resource as compared with the production activities of other industries, so it is the main reason of increasing of the Earth's environment. In Korea, as people become aware of the need of technical and institutional infrastructure for the recycling of construction wastes, they manage Allbraro system which is Total Management System in the wastes. Therefore, they promote the handling of standardized information, processing construction waste of transparency procure and promotion of the efficiency of task about the disposal of occurrence and movement of real-time construction waste. However, objective information for dismantling building did not construct in the organization of the system, so the emission of system randomly produces and discharges information of the waste. Because of that reasons, the exact value of waste abandonment is difficult to measure and recycling after waste disposal has the limit point. Therefore, in this study, advantages and disadvantages of the existing waste management system are analyzed, and we improved solution of construction building and environment of the city when BIM / GIS are utilized.

• Journal of the Korea Organic Resources Recycling Association
• /
• v.12 no.2
• /
• pp.52-60
• /
• 2004

The basic approach to sewage sludge is organic waste minimization, promotion of energy recovery; volume and weight reduction by final treatment, and environmentally final disposal of natural circulation. Dry and pyrolysis of maize was experimentally investigated in full-scale rotary kiln in semi-continuous operation. The operational parameters varied are the operating temperature $160{\sim}175^{\circ}C$ of dry and $450{\sim}800^{\circ}C$ of pyrolysis, the solids residence time 9 min for pyrolysis. Important parameters studied include the running time, water content of sewage sludge, solids amount of sewage sludge(TS%) by the varied temperature. Also, with the increasing of temperature, how the yield of oil and char product change was observed, and the distribution of gas production components was observed. The gas of $C_1{\sim}C_3$ yield increased and oil of $C_4{\sim}C_6$ yield decreased along with pyrolysis temperature of $670^{\circ}C$ by the run time of 9 min.

• Resources Recycling
• /
• v.11 no.6
• /
• pp.18-23
• /
• 2002

A study on the solvent extraction of hexavalent chromium from aqueous solutions has been investigated. The results showed that the extraction efficiency of chromium increased in proportion to extractant concentration. Aliquat 336 of quarternary amine effectively extracted hexavalent chromium and was superior to Alamine 336. And the stabilizers like polyhydric alcohols of octanol, decanol and dodecanol showed the similar effect fur prevention of third phase and a little promotion of extraction efficiency in comparison with non-use of polyhydric alcohols. On the other hand, in solvent extraction of hexavalent chromium from aqueous solutions, the hexavalent chromium was completely extracted at pH range lower than 7 with 1% Aliquat 336 as extractant and 5% decanol as stabilizer and the hexavalent chromium in extractant was completely stripped with 1M sodium hydroxide solution in the stripping step.

• Resources Recycling
• /
• v.24 no.6
• /
• pp.3-8
• /
• 2015

Gasification characteristics and gas produced from a sewage sludge char were analyzed by using a thermobalance reactor, which is used for a reaction kinetic analysis by measuring weight change of materials at a desired temperature. Gasification reaction rate increased with increasing temperature and steam partial pressure due to the promotion of gasification reaction. Three models of gas-solid reaction were applied to the reaction kinetics analysis and modified volumetric reaction model was an appropriated model for the steam gasification of the sewage sludge char. Apparent activation energy and pre-exponential factors were evaluated as 155.5 kJ/mol and $14,087s^{-1}atm^{-1}$, respectively. The order of reaction on steam partial pressure was 0.68. Gas analysis was performed at $900^{\circ}C$ and hydrogen concentration was highest in the gas concentrations, which increased with increasing the steam partial pressure. Hydrogen concentration increased the most and hydrogen concentration in the produced gas was 2-4 times higher than that of carbon monoxide due to the gasification and water gas shift reaction.

• Resources Recycling
• /
• v.5 no.3
• /
• pp.3-8
• /
• 1996

The settling charaderist~aU I flocculation of Dae-mynng kaolin were studicd by measurrng the electropharetic mnhilbty and the light transmittance of suspensions with various concentrations of floccul;mnts, hydragcn inn and ~ I ~ c t r ~ l y t e s . Isoelectric points of kaolin occurred at pH 3.2. The fine particle cnagulation of kaolin \\'as achieved must cffcctivcly a1 the isoelcctric points. The optinurn flocculation of Accofloc was occurred when thc concentration w;o 4 ppm. and thc coagulation became greater in thc order of an~onic,n al>~aniacn d catiomc. The flocculation of Accofloc(C-4S2) \\,as more effective lhan that of Superfloc(C-577) No cffeectiveness was found whcn NaCl was added, hut flocculations oi nonionic and anionic were more effective when NaCl and flacculants werc added.

• Resources Recycling
• /
• v.25 no.6
• /
• pp.82-91
• /
• 2016

The framework act on resource circulation was got through the Korea National Assembly in May, 2016. It is the most important to analyze and understand its purpose, main contents, and policy direction of the framework act because this act will lead the resource circulation policy. Korea government is going to enact subordinate statutes such as its enforcement decree and regulation to enforce the act in January, 2018. No later than enforcement of the act, its subordinate statutes should be studied indepth and consulted without any bias in order to satisfy the intent - promotion of transition toward a resource circulation society - of the act. Therefore, in this study, the points in dispute in the act are indicated and the issues and specific directions of key articles are reviewed. The ideas to maximize the effectiveness of its subordinate statutes are also suggested.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.6
• /
• pp.739-750
• /
• 2023

The quality certification for recycled aggregate is governed by the Construction Waste Recycling Promotion Act, overseen by the Ministry of Environment. The specific criteria for this certification are detailed in the Regulations on Quality Certification and Management of Recycled Aggregate, a mandate of the Ministry of Land, Infrastructure, and Transport. These regulations were initially enacted on April 10, 2006, and have undergone a total of 16 revisions to date, the most recent being on December 23, 2021. This paper delves into the revision history of these pivotal regulations pertaining to quality certification over the past 17 years, with a particular focus on the latest revision, which encompasses significant changes, including those in follow-up management. This analysis aims to aid stakeholders in the recycled aggregate sector, including 402 certified companies, in comprehensively understanding the government's strategic direction for quality certification and to encourage the recycling of construction waste by bolstering the quality certification process.

• Industry Promotion Research
• /
• v.5 no.1
• /
• pp.13-20
• /
• 2020

This study is about consumer preference of plastic toilets that can provide automatic supply of recycled water. First, the preference for plastic toilet seat design by gender and age group was preferred for gender type C and G for the sex. As the result of the chi-square test, the significance probability is .044 and the significance is P <.0 5. I could confirm that. Age, teens, 40 s, and 50 s or older prefer type C, 20 s and 30 s, but B type is not statistically significant. Second, the differences among the groups of preference for appearance design criteria according to general characteristics were all stable (stable appearance) in gender, age, region, education, and salary, but the chi-square test showed that they were not statistically significant. There was no difference between them. This study has implications for improving competitiveness and productivity by reducing the main production cost by commercializing toilets made of plastic materials.

• Industry Promotion Research
• /
• v.1 no.1
• /
• pp.143-149
• /
• 2016

This study verified the relationship on the perception of water reuse R&D support and water reuse vitalization policy. The study results showed that the perception of water reuse importance and effectiveness positively affected the perception of the necessity of water reuse vitalization policy, necessity of supporting water reuse water-saving product company, necessity of investing water reuse(p<.001). Also, gender, education, occupation, type of residence and monthly water rate significantly affected the between-group differences of the perception of water reuse vitalization policy. This study provided implications for preparing water reuse investment and vitalization policy by the relationship on the perception of water reuse R&D support and water reuse vitalization policy.