• Journal of the Korean Geotechnical Society
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• v.24 no.5
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• pp.5-13
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• 2008

This paper proposed an environmental standard far beneficial use of dredged materials currently considered as waste materials. In Korea, even though chemical analysis of sediments are carried out frequently, their analysis results were not interrelated with the effects of biological lives due to a shortage of data, which may result in difficulty to develope Korean standards for reusing dredged materials. For these, this paper first searched existing foreign standards, analyzed local contaminated sediment data, identified their main components of contaminations and then compared clean-up standards of sediments consisting of lower and higher level. From these analyses new environmental standards considering Korean domestic circumstances are proposed. It is judged that newly proposed standards are appropriate in terms of both Korean national sedimental environments and economical recycling aspects because environmental standard levels proposed are higher than background level of sediments in Korea and foreign country's standards, where many experiences and environmental monitoring works have been already performed.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.91-96
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• 2023

To verify the quality of bubbles during the use of quartz glass crucibles (QC), an appropriate accelerated testing method was proposed. The bubble state of discarded waste crucibles obtained from actual Czochralski (Cz) processes was analyzed, and optimal heat treatment conditions were suggested by varying temperature, pressure, and time using the QC test piece. By subjecting the samples to heat treatment at 1450℃, 0.4 Torr, and 40 hours, it was possible to control the bubble size and density to a similar level as those generated in the actual Cz process. In particular, by selecting a relatively lower pressure of 0.4 Torr compared to the typical range of 10~20 Torr applied in the Cz process, the time required for accelerated bubble formation testing could be reduced. However, it was determined that increasing the heat treatment temperature to 1550℃ led to the phenomenon of Ostwald ripening, resulting in larger bubbles and a rapid decrease in density. Therefore, it was concluded that it was not a suitable condition for the desired b ake test.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.390-390
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• 2013

Use of recycled aggregates in portland cement concrete construction can offer benefits associated with both economy and sustainability. Testing performed to date indicates that RBMA can be used as a 100% replacement for conventional coarse aggregate in concrete that exhibits acceptable mechanical properties for use in structural and pavement elements, including satisfactory performance in some durability tests. RBMAC is currently not used in any type of construction in the United States. However, use of RBMAC could become a viable construction strategy as sustainable building practices become the norm. Rating systems such as LEED offer points for reuse of building materials (particularly on-site) and use of recycled materials. If renovations at an existing facility call for the demolition of existing brick masonry constructions, the rubble could be included as RBMA in new concrete pavement, sidewalks, or curb and gutter. Other potential uses for RBMAC could include those in the precast concrete industry, particularly in architectural precast concrete applications. In addition to providing acceptable strength and economy, the color of RBMA could be an attractive component of architectural precast concrete panels or other façade components. This paper explores the feasibility of use of RBMAC in several types of sustainable construction initiatives, based upon the findings of previous work with RBMAC produced from construction and demolition waste from a case study site. Guidance for obtaining and using RBMA is presented, along with a summary of material properties of RBMAC that will be useful to construction professionals.

• Food Science of Animal Resources
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• v.44 no.2
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• pp.284-298
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• 2024

Restructured meat (RM) products are gaining importance as an essential component of the meat industry due to consumers' interest in health benefits. RM products imply the binding or holding of meat, meat by-products, and vegetable proteins together to form a meat product with meat's sensory and textural properties. RM products provide consumers with diversified preferences like the intake of low salt, low fat, antioxidants, and high dietary fiber in meat products. From the point of environmental sustainability, RM may aid in combining underutilized products and low-valued meat by adequately utilizing them instead of dumping them as waste material. RM processing technique might also help develop diversified and new hybrid meat products. It is crucial to have more knowledge on the quality issues, selection of binding agents, their optimum proportion, and finally, the ideal processing techniques. It is observed in this study that the most crucial feature of RM could be its healthy products with reduced fat content, which aligns with the preferences of health-conscious consumers who seek low-fat, low-salt, high-fiber options with minimal synthetic additives. This review briefly overviews RM and the factors affecting the quality and shelf life. Moreover, it discusses the recent studies on binding agents in processing RM products. Nonetheless, the recent advancements in processing and market scenarios have been summarized to better understand future research needs. The purpose of this review was to bring light to the ways of sustainable and economical food production.

• Computers and Concrete
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• v.33 no.6
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• pp.707-724
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• 2024

This paper proposes a study of cement replacement with rice husk ash (RHA) and eggshell ash (ESA) for enhanced mechanical properties of geopolymer (GP) concrete with and without admixture. The main objective is to investigate the mechanical properties of GP with various replacement levels of Pozzolana Portland cement by RHA and ESA. The GP resistance to durability is examined and impact of ash materials on concrete's durability performance is determined. The environmental benefits of using agricultural waste materials in GP manufacturing minimize cement usage and CO2 emissions. The goal is to assess value of RHA-ESA of building material, paving stones for structures to lessen environmental impact. The novelty lies in use of ESA and RHA as partial replacements for cement and investigation of admixtures to enhance concrete properties, and reduce environmental impact. The research contributes by introducing a novel approach to reducing cement consumption by using ESA and RHA to address environmental concerns. It also explores the potential benefits of admixtures improving concrete performance and reducing environmental pollution. A study is carried with and without impacts of admixture to find compressive strength of GP cubes. The cement has been replaced by RHA and ESA in the range of (2.5%+7.5%, 5%+5%, 7.5%+2.5) by weight of cement for M20 mix. The compressive strength (CS) and split tensile strength (STS) at 7days, 14 days and 28 days is obtained as 21 N/mm2 at 7.5%RHA+2.5%ESA and 2.3 at 7.5%RHA+2.5%ESA, 24 N/mm2 at 7.5%RHA+2.5%ESA and 2.3 at 7.5%RHA+2.5%ESA, 28 N/mm2 at 7.5%RHA+2.5%ESA and 2.8 at 7.5%ESA respectively with normal curing condition.

• Journal of the Korean Recycled Construction Resources Institute
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• v.4 no.3
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• pp.250-258
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• 2016

Until now, the construction material industry has been recognized as a typical environmental destruction industry. However, recently, in order to reduce $CO_2$ emission, the main cause of environmental problems, lots of studies have been done about recycling industrial by-products and construction wastes. Therefore, the purpose of this study is to confirm whether it is possible to use as an alternative material in cement production process as a part of the development of recycled cement using an inorganic construction waste. For this study, the inorganic construction wastes was collected and analyzed each chemical component by XRF(X-ray Fluorescene). Also, the inorganic construction wastes were combined based on the chemical component of the cement, to perform this analysis. As a result, when the inorganic construction wastes was properly combined, it is possible to consider the development of the recycled cement used the inorganic construction wastes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.10
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• pp.1422-1429
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• 2009

Alaska pollock roe is mainly used as a raw material for fermented seafood, especially in the East Asia. Kernels of Alaska pollock roe are not valuable as a raw material and usually discarded as a waste product. In order to utilize the broken roes of Alaska pollock, the smoked product, a imitated sausage, was manufactured for commercial production. Texture intensity (hardness and gumminess) and sensory evaluation (taste and acceptability) of the smoked Alaska pollock roe packed with collagen casing were evaluated based on mixture design and regression models. At higher concentration of carrageenan and lower concentration of starch in the formula of the smoked Alaska pollock roe, higher texture intensity and sensory scores were obtained. pH values of all treatments (control, vacuum and $N_2$ packages) increased up to 6.28, 6.23 and 6.24 on 4 months of storage, respectively, and then decreased. The numbers of VBN, TBA and viable cell counts increased during storage periods, higher in control than in vacuum and $N_2$ packages. Coliform bacteria was not detected in all treatment during storage periods.

• Journal of the Korea Organic Resources Recycling Association
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• v.28 no.2
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• pp.15-29
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• 2020

The aims of this study is to improve physical properties of the sewage sludge and the process sludge generated in the leachate treatment by mixing the dry fuel, to develop the neutral solidifing agents that reduce oder, and to recycle the sewage and the process sludges as landfill cover materials. The mixing ratio (W/W) of sludges and dry fuel was appropriate at about 1:1, and the mixed materials were shown to be homogeneous at that ratio. We could know that when the sludges were mixed with dry fuel, moisture contents and viscosities are reduced, and air passages are formed between particles and particles. The various mixing tests and odor tests showed that the neutral solidifing agent was effective for the odor reduction. The main ingredient of the solidifing agent is the ash of sewage sludge, enabling it competitive in waste recycling and production costs. The landfill cover, using developed neutral solidification agent, improved physical properties to satisfy the quality standards and to increase the compressive strength. It also proved to reduce the value of complex oder and the usage of solidification agent to 1/3 (3,000 to 1,000) and to 1/8 (50% to 6%), respectively, from the comparative study with alkaline solidified landfill cover. Further research is under way to prove that this can be mixed with general soil to be used as a soil improvement agent for plant cultivation.

• Journal of Korean Society of Environmental Engineers
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• v.33 no.10
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• pp.767-773
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• 2011

The purpose of this study was to investigate the possibility of an alternative fuel resource by incinerating a mix of combustible MSW (municipal solid waste) and offals after separating recyclable material at the MRF (material recovery facilities) location. We analyzed the physical and chemical properties including the 3-contents, the calorific value, and chemical compositions of the separation rejects in MRF, and compared the results with combustible MSW. Moreover, we experimented the trend of combustible properties and the concentration change of air pollutants at mixed incineration in the MSW incinerator. According to the results of the experiment, the separation rejects showed higher heating value (5,865 kcal/kg), and lower moisture and ash content than combustible MSW. Since we have incinerated MSW in the MSW incinerator mixing the offals at 30% and 50% respectively, we know that the change of the concentration of dust, $SO_2$, $NO_2$, and CO did not appear significant, and not exceed the pollutants emission regulation. But, considering the enhancement of the HCl emission concentration (max. 33.7 ppm) at the co-incineration of the 50% offals, we believe that the proper mixing ratio of the separation rejects would become within 30%.

• Resources Recycling
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• v.15 no.2 s.70
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• pp.50-57
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• 2006

Production of activated carbon from woody fish parking cases has been studied using waste sulfuric acid as an activating agent for the purpose or promoted recycling of woody fishing port wastes. The adsorption capacity of produced activated carbon was observed to increase with activation temperature and reached its maximum at ca. $650^{\circ}C$ under the experimental conditions. However, the adsorption capacity of activated carbon became deteriorated above this temperature due to the thermal degeneration of its structure. Optimal activation time was found to be about 120 minutes and 1:3 weight ratio of raw material and activating agent was appropriate for increased adsorption capacity of activated carbon under the conditions of $550^{\circ}C$ and 60 minutes of activation time. Regarding the effect of the concentration of activating agent on activation, ca. 1.2 M of sulfuric acid was observed to be proper for an optimal activation or raw material. Comparison of the activation power of sulfuric acid with nitric acid showed that sulfuric acid was superior to nitric acid, however, with regard to the yield of activated carbon there was no significant difference between the two activating agents. The degree of dispersion of carbon particles was shown to be relatively high in neutral condition and the produced activated carbon was considered to be effectively employed for the treatment of metal ions in wastewater due to its negative surface charge in aqueous condition.