• Journal of the Korean Society of Radiology
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• v.15 no.6
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• pp.855-860
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• 2021

Coffee is a popular beverage not only in Korea but also around the world, and its consumption is on the rise. As coffee consumption increases, coffee waste are also increasing, and recycling is attempted in various fields. However, these recycling methods require complex recycling processes and specialized skills. However, in this study coffee waste, agar powder, and powdered glue were mixed in an appropriate ratio and used as a cement building finishing material. This recycling method has a simple manufacturing method and was shown to improve indoor air quality by delaying radon emitted from cement walls for 2.5 hours with one application and 3.9 hours with two applications. In addition, it was shown that after applying the coffee waste mixture, it was applied twice to close the cracks that occurred during the drying process, thereby prevent the coffee waste from falling off the wall for aesthetic perfection.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.3
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• pp.185-194
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• 2022

Coffee is one of the most consumed beverages in the world and is the second largest traded commodity after petroleum. Due to the great demand of this product, large amounts of waste is generated in the coffee industry, which are toxic and represent serious environmental problems. This study aims to study the possibility of recycling spent coffee grounds (SCG) as a mineral admixture by replacing the cement in the manufacturing of concrete. To recycle the coffee g rounds, the SCG was dried to remove moisture and fired in a kiln at 850 ℃ for 8 hours. Carbonized coffee grounds are produced as coffee grounds ash (CGA) through ball mill grinding. The chemical composition of the prepared coffee grounds ash was investigated using X-ray fluorescence (XFR). According to the chemical composition analysis, the major elements of coffee grounds ash are K₂O(51.74 %), CaO(15.92 %), P₂O₅(14.39 %), MgO(7.74 %) and SO₃(6.89 %), with small amounts of F₂O₃(0.66 %), SiO₂(0.59 %) and Al₂O₃(0.31 %) content. To evaluate quality and mechanical properties, substitutions of 5, 10, and 15 wt.% of coffee grounds ash (CGA) were tested. From the quality test results, the 28-day activity index of CGA5 reached 80 %, and the flow value ratio reached 96 %, which is comparable to the minimum requirement for second-grade FA. From the test results of the mortar, the optimal results have been found in specimens with 5 wt-% coffee grounds ash, showing good mechanical and physical properties.

• Journal of Energy Engineering
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• v.26 no.4
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• pp.14-22
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• 2017

Coffee consumption has been increased all around world as well as in South Korea. Coffee by-products occurred from the coffee consumption also have been rapidly increased, but the technology and methods to handle the by-product have not been much developed, resulting the severe environmental problems in soil and water. In order to solve this environmental problem, using the coffee by-product, eco-friendly and cheap methods for the recycling have been actively discussed and suggested. In this article, we discussed the types and characters of the coffee by-product and investigated the trend about the methods for utilizing the coffee by-product. In addition, we figured out the current status of coffee waste in Seoul, South Korea and discussed plans that Seoul government is working on to handle the coffee waste.

• Journal of the Korean Recycled Construction Resources Institute
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• v.10 no.1
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• pp.15-22
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• 2022

In this study, the hydration reaction and strength characteristic of cement mortar with spent coffee ground(SCG) was investigated. As a result of the study, it was found that as the firing temperature of the SCG increased, the mass loss due to the combustion of organic matter increased, but the density increased. In addition, when the SCG were mixed, SCG interfered with the hydration reaction and the compressive strength was significantly lowered. On the other hand, the coffee grounds ash(SCG_Ash) calcined at 800 ℃ showed a hydration reaction and a compressive strength equivalent to or higher than that of OPC mortar.

• Food Science and Preservation
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• v.18 no.1
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• pp.33-38
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• 2011

We investigated the quality characteristics of cookies prepared after addition of various concentrations of used coffee grounds (0%, 1%, 3%, and 5%, all w/w) as a substitute for flour. As coffee grounds concentration rose, decrease in the pH of cookie dough was evident. In terms the water-holding capacity of dough, cookies prepared 3% (w/w) coffee grounds yielded the highest value. With an increase in coffee grounds concentration, the color a value rose, but the L and b values fell. The gelatinization temperature became higher, but both peak viscosity and 15 min-height values declined. The spread and loss ratios decreased but the leavening rate rose significantly with elevation of coffee grounds concentration. The hardness of cookies rose but slightly, as coffee grounds concentration rose. Upon sensory evaluation of all of appearance, flavor, and overall preference, cookies prepared with addition of used coffee grounds were superior to those without grounds, whereas those prepared using 1%-3%(w/w) coffee grounds showed the highest overall acceptability. Thus cookies made using coffee grounds can be economically competitive. In addition, the ingredients of coffee powder and used coffee grounds were shown to be very similar, except that coffee grounds contain 15-fold less caffeine than dose coffee powder. As health concerns are popular today, the use of coffee grounds to manufacture processed food may be acceptable.

• Resources Recycling
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• v.30 no.1
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• pp.77-82
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• 2021

Reduction of CO2 emissions is an important issue in the steel industry, and the research on carbon materials that can partially replace cokes is necessary to reduce CO2 emissions. Meanwhile, the biomass fuel contains some fixed carbon, and the carbon content in the biomass can be increased by torrefaction. As one of the biomass fuels, coffee grounds contains about 55 mass% of carbon, and its about 270,000 tons are landfilled and incinerated annually in Korea. In addition, research on the recycling process due to the increase in annual coffee consumption is required. In this study, the effect of temperature on the concentration of fixed carbon in coffee grounds was investigated during torrefaction. Moreover, the effects of mixing ratio of torrefied coffee grounds with cokes on the carbon concentration and dissolution efficiency in the metal sample were investigated.

• Resources Recycling
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• v.30 no.3
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• pp.70-81
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• 2021

This study evaluated the recyclability of waste plastics in used coffee capsules disposed of as municipal waste. For recycling, a new material separation process was developed to remove the coffee grounds through primary crushing, washing, sieving, and secondary crushing, followed by corona discharge electrostatic separation. Furthermore, for the under 10 mm size fraction samples, the aluminum removal and the plastic recovery were 95.4% and 98.3%, respectively, under optimal conditions. In addition, for the 15 mm fraction samples, the aluminum removal and the plastic recovery were 91.3% and 97.2%, respectively. To evaluate the recyclability of the separated waste plastics, the samples were pelleted, and their material properties were analyzed. No hazardous substances were detected, and the results were similar to those for homo-PP. Therefore, it was confirmed tha t sufficient functiona lity existed a s recycled PP. However, owing to the da rk color of the pellets, limited applications to black or dark products are expected.

• Journal of the Korea Organic Resources Recycling Association
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• v.22 no.2
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• pp.44-49
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• 2014

In order to remove the heavy metals from synthetic wastewater containing Pb, Cr, and Cd, the experiment was conducted with a variety of concentration and pH by using the washed and dried coffee grounds as adsorbent. Almost of the heavy metals were removed in thirty minutes and the removal efficiency was maximized to the 80 percents following the different pH conditions. Furthermore, in the case of Cr, the removal efficiency was declined with the increasing of pH. As a result of this study, coffee grounds is proved to be a very good adsorbent to remove the heavy metals.

• Magazine of RCR
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• v.16 no.4
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• pp.65-69
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• 2021

• Korean Journal of Food Science and Technology
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• v.49 no.5
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• pp.544-549
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• 2017

The spent coffee grounds (SCG) are considered valuable by-products because they contain various bioactive compounds. The SCG extraction (SCGE) was irradiated at doses ranging between 30 and 50 kGy. The deep dark-brown color of SCGE was changed to a bright yellow color by gamma irradiation. The content of the bioactive compounds of gamma-irradiated SCGE was analyzed by high-performance liquid chromatography. Interestingly, the content of quinic acid was increased by gamma irradiation, whereas other compounds were decreased. Although the contents of bioactive compounds were changed by gamma irradiation, the biological activities (radical scavenging activity and whitening effects) of SCGE were unaffected. Our findings suggest that gamma irradiation can effectively improve the color values of SCGE without the loss of biological activities. Consequently, gamma irradiation can be a useful tool for improving the utilization of SCGE in the cosmetic industry.