• Journal of the Korea Institute of Building Construction
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• v.18 no.3
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• pp.219-225
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• 2018

The aim of the research is improving the quality of concrete by using the alternative aggregate resources and recycling wastes. To make a combined aggregate fitted in standard particle size distribution curve, crushed sand from blasted rock debris was used as a base aggregate. Additionally, to increase the portion of fine particles, sea sand was mixed. Although these aggregate combination fit the standard particle size distribution curve, in this research, raw coal ash was replaced as a microfine. According to the experiment, by replacing 5% raw coal ash, the most favorable results were achieved in aggregate gradation and cement mortar quality.

• Resources Recycling
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• v.19 no.1
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• pp.13-20
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• 2010

Much energy is consumed up when making a concrete. And especially, because lots of $CO_2$ is discharged for combination material, cement, we are making efforts in order to get lid of this negative thought. Recently, much interest is given to manufacturing eco concrete which is environment friendly and its' application. We should study manufacturing of the concrete whose environment friendly performance should be improved as consistent development concept in order for various approaches to be settled down our country such as lowering of environmental load, utilization of industry wastes and improvement of environment related performance. This study inquired into utilization possibility through from various tests results after manufacturing eco type mixed concrete whose purpose is to lower environmental load in which cement and aggregates can be replaced with metakaolin which is natural material and copper slag which is industry by product.

• Journal of the Korea Organic Resources Recycling Association
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• v.5 no.1
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• pp.1-13
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• 1997

The fermentative conversion of food wastes into feed was investigated by seeding of mixed inoculum YM (Youngjin Environmental co.), and thermotolerant yeast Kl. marxianus. For 6 days' fermentaion, the fermentation method of 2 days' aerobic followed by 4 days' anaerobic was better for the production of organic acids and increasing total microbial population than 6 days' continuous aerobic or anaerobic fermentation. By seeding YM, the total microbial count increased about 100 times of the control group. In addition, Kl. marxianus seeding together with YM increased total viable cell count, but did not increase yeast count significantly.

• Journal of the Korea Organic Resources Recycling Association
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• v.15 no.2
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• pp.98-108
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• 2007

In order to use food wastes for the source of fermented feed for pigs, this study was aimed to produce better culture inoculum by the aeration and addition of pig' s blood meal as sub nutrient. For the preparation of inoculum as bacterial strain, Lactobacillus brevis isolated from pig intestine, and a yeast Saccharomyces cerevisiae from strawberries were used. Molasses and whey were used as main ingredients for the culture solution as well as yeast extract and other ingredients as sub nutrients. As the experimental result, aeration showed a positive effect to enhance viable cell count or retarding death phase. Although sub nutrient yeast extracts were replaced with pig's blood meal, fermentation characteristics were almost similar to that of yeast extract. When the inoculum was stored at room temperature, L. brevis and S. cerevisiae maintained the viable cell concentration of approximately 8 log cfu/mL for 1 week. 2 Days after the culture solution was mixed with food waste, the number of unwanted bacteria had rapidly increased, but E.coli was not detected for 5 days.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.10a
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• pp.59-61
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• 2005

In Korea, hundreds of abandoned and closed coal and metallic mines are present in the steep mountain valleys due to the depression of the mining industry since the late 1980s. From these mines, enormous amounts of coal waste were dumped on the slopes, which causes sedimentation and acid mine drainage (AMD) to be discharged directly into streams causing detrimental effects on soil and water environments. A limestone slurry by-product (lime cake) is produced from the Solvay process in manufacturing soda ash. It has very fine particles, low hydraulic conductivities ($10^{-8}{\sim}10^{-9}cm/sec$), high pH, high EC due to the presence of CaO, MgO and $CaCl_2$ as major components, and traces of heavy metals. Due to these properties, it has potential to be used as a neutralizer for acid-producing materials. A field plot experiment was used to test the application of lime cake for reclaiming coal wastes. Each plot was 20 x 5 m (L x W) in size on a 56% slope. Treatments included a control (waste only), calcite ($CaCO_3$), and lime cake. The lime requirement (LR) for the coal waste to pH 7.0 was determined and treatments consisted of adding 100%, 50%, and 25% of the LR. The lime cake and calcite were also applied in either a layer between the coal waste and topsoil or mixed into the topsoil and coal waste. Each plot was hydroseeded with grasses and planted with trees. In each plot, surface runoff and subsurface water were collected. The lime cake treatments increased the pH of coal waste from 3.5 to 6, and neutralized the pH of the runoff and leachate of the coal waste from 4.3 to 6.7.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.4
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• pp.147-152
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• 2000

For the probiotic feed production from residual food waste by using the yeast Kluyveromyces marxianus, aerobic liquid fermentation was attempted at $35^{\circ}C$. After grinding finely, optimal fermentation conditions of the substrate was investigated in shaking incubator. By controlling water content yeast growth was studied at each different solid content of 5, 10 and 15% respectively. The most active growth of the yeast was shown at 10%. For the stimulation of the cell growth, mixed culture with Aspersillus oryzae was conducted in a 2 litre-jar fermenter. As the results, the yeast growth rate was increased, but the maximum viable cell count amounted was slightly higher as $3.5{\times}10^9/ml$ than single culture.

• Economic and Environmental Geology
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• v.39 no.2 s.177
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• pp.173-180
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• 2006

The synthesis of polyphase waste form, which is an immobilization matrix fur the high level radioactive wastes, was performed with the mixed composition of garnet and spinel $(Gd_3Fe_5O_{12}+(Ni_xMn_{1-x})(Fe_yCr_{1-y})_2O_4)$ in the range of 1200 to $1400^{\circ}C$. The phases synthesized from all stoichiometric compositions were garnet, perovskite, and spinel. Especially, garnet was synthesized only in the composition of the highest content of Fe(y=0.9), whereas it was not synthesized in other compositions. This result indicated that the content of Fe was closely related to the formation of garnet. The composition of garnet revealed that the content of Gd was exceeded and that of Fe was depleted. Preferential distribution of elements in the phases can be attributed to the nonstoichiometric composition of garnet.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.2
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• pp.56-62
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• 2013

Organic wastes are not disposing object but renewable resources. One of those ways of rendering to resources, composting is environmentally friendly way as to aspect of recycling of resources. Regardless of ways, composting goes through the main processes which are fermentation process and curing process. In the study, mobile composting device was developed with the experiments which were performed to solve the problems of fermentation and curing process. Since reaction vessel is rotated, it does not cease in the middle of agitation because of foreign. In addition, it mixed as well. With maintaining uniform temperature of reaction vessel by controlling amount of air, fermentation and curing are easy to use. Its economic feasibility is better than the existing fermentation equipments. Furthermore, it benefits to reduce the personnel and materiel maintenance cost, and mass produce composting product which use organic waste. Especially, although it needs less space, it has effect to provide transferable composting device with available area to increase by contacting organic waste to air.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.506-510
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• 2009

The effects of various organic wastes on anaerobic fermentative hydrogen production were studied using enriched mixed microflora in batch tests. Rotten fruit, corn powder and organic wastewater enriched with sulfate (up to 1,000 mg/L) were used for experiments. Maximum hydrogen production (547.1 mL) was observed from rotten apple with initial substrate concentration of 132.2 g COD/L. The experimental result on sulfate enriched organic wastewater indicated that hydrogen production is not adversely influenced by relatively high sulfate concentration. Residual sulfate content remained at 96-98 % after 75 hours of reaction, which showed that no major sulfate reduction was occurred at pH 5.3-5.5 in the reactor. The volatile fatty acid (VFA) fractions produced during the reaction was in the order of butyrate > acetate > propionate in all experiments. The results of this study would be useful for controlling the conditions on fermentative hydrogen production using different feedstocks.

• New & Renewable Energy
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• v.10 no.1
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• pp.30-40
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• 2014

The main object of this study was to offer information about incoming waste in landfill and to evaluate biochemical methane and hydrogen sulfide potentials of landfill wastes. We examined brick, soil, mixed waste (C&D waste and MSW) samples for the study. The leaching experiments showed that BOD, COD and sulfate were determined in the range of 0~18,816 mg/kg, 85~21,100 mg/kg and 160~1,205 mg/kg, respectively in 6hr extraction test. An accumulated extraction tests for 140day were determined BOD 226~197,219 mg/kg, COD 436~242,588 mg/kg and Sulfate 1,090~25,140 mg/kg. Also, BMP (biochemical methane potential) tests were carried out to examine methane and hydrogen sulfide yields for the 3 different wastes. As a result, methane yield was determined to 262.68 mL $CH_4/g$ VS of MSW and 0~17.75 mL $CH_4/g$ VS in brick, soil and C&D waste. Higher hydrogen sulfide yield was observed to 0.079mL $H_2S/g$ VS in C&D waste. This result indicate that brick and soil could be sources of sulfate, and higher production of hydrogen sulfide could be odor problem and inhibitor of methane production.