• Environmental Engineering Research
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• v.23 no.4
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• pp.456-461
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• 2018

The solid-state anaerobic digestion (SS-AD) has promoted the development and application for biogas production from biomass which operate a high solid content feedstock, as higher than 15% of total solids. However, the digested byproduct of SS-AD can be used as a fertilizer or as solid fuel, but it has serious problems: high moisture content and poor dewaterability. The organic residue from SS-AD has to be improved to address these problems and to make it a useful alternative energy source. Hydrothermal carbonization was investigated for conversion of the organic residue from the SS-AD of livestock waste to solid fuels. The effects of hydrothermal carbonization were evaluated by varying the reaction temperatures within the range of $180-240^{\circ}C$. Hydrothermal carbonization increased the calorific value through the reduction of the hydrogen and oxygen contents of the solid fuel, in addition to its drying performance. Therefore, after the hydrothermal carbonization, the H/C and O/C atomic ratios decreased through the chemical conversion. Thermogravimatric analysis provided the changed combustion characteristics due to the improvement of the fuel properties. As a result, the hydrothermal carbonization process can be said to be an advantageous technology in terms of improving the properties of organic waste as a solid-recovered fuel product.

• Journal of Microbiology and Biotechnology
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• v.29 no.10
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• pp.1624-1628
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• 2019

Banana planting altered microbial communities and induced the enrichment of Fusarium oxysporum in rhizosphere compared with that of forest soil. Diseased plant rhizosphere soil (WR) harbored increased pathogen abundance and showed distinct microbial structures from healthy plant rhizosphere soil (HR). The enriched taxon of Bordetella and key taxon of Chaetomium together with some other taxa showed negative associations with pathogen in HR, indicating their importance in pathogen inhibition. Furthermore, a more stable microbiota was observed in HR than in WR. Taken together, the lower pathogen abundance, specific beneficial microbial taxa and stable microbiota contributed to disease suppression.

• Korean Journal of Agricultural Science
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• v.49 no.3
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• pp.397-405
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• 2022

Castor oil cake is widely used as a raw material for organic fertilizers (OF) in Korea. Compared to other fertilizer raw materials, it is highly dependent on imports. In terms of replacing raw materials, dehydrated food waste powder (FDP) and castor oil cake have similar nutritional content, and if 30% is replaced, about 20% of the raw material cost can be saved. However, few studies on the effects on crop growth and soil properties when organic fertilizer and dry food waste powder are mixed and applied to the soil have been reported. The effects of an organic fertilizer made by mixing the commercial available organic fertilizer with dehydrated food waste (OF + FDP) on soil properties and the growth of two types of leafy vegetables (lettuce and young radish) were evaluated and compared with the performance of OF. The fresh weights of lettuce and young radish were the highest with OF amendment and stood at 114.3 and 119.0 g·plant^-1, respectively. These were followed by OF + FDP amendment, which produced 103.1 and 109.6 g·plant^-1, respectively. Compared to the control, OF and OF + FDP increased the lettuce fresh weights by about 69% and 52%, respectively, while the fresh weights of the radish were increased by about 223% and 207%, respectively. The soil pH, EC, total carbon content, and organic matter content in OF and OF + FDP increased. The mixture of dehydrated food waste powder and organic fertilizers is expected to improve soil quality and facilitate stable production of crops and contribute to the substitution of imported organic fertilizer raw materials.

• 한국연소학회:학술대회논문집
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• 2005.10a
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• pp.238-244
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• 2005

This study performs the pilot-plant experiments to evaluate the effect of the oxygen enrichment on the co-incineration of municipal solid waste and organic sludge from a wastewater treatment facility. The design capacity of the stoker-type incinerator pilot-plant is 150 kg/h. Combustion chamber temperatures were measured as well as the stack gas concentrations, i.e., NOx, CO, and the residual oxygen. The maximum ratio of organic sludge waste to the total waste input is 30%. Also the oxygen-enriched air with 23% of oxygen in supplied air is used for stable combustion. As the co-incineration ratio of the sludge increased up to 30% of the total waste input, the primary and the secondary combustion chamber temperature was decreased $to900^{\circ}C$ (primary combustion chamber), $750^{\circ}C$(secondary combustion chamber), respectively, approximately $200^{\circ}C$ below the incineration temperature of the domestic waste only (primary: $1,100^{\circ}C$, secondary: $950^{\circ}C$). However, if the supplied air was enriched to 22% oxygen content in air, the incinerator temperature was high enough to burn the waste mixture with 30% sludge, which has the heating value of 1,600 kcal/kg.

• Journal of Environmental Science International
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• v.23 no.2
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• pp.303-312
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• 2014

As for chemical characteristics of cultivated media waste, the total content of nitrogen, phosphoric acid, and potassium was 6.93%; organic matter content was 67.78%; pH and EC were 7.20 and 1.46 ds/m, respectively. Organic acids identified during stabilization included citric acid, oxalic acid, fumaric acid, and acetic acid, which was highest. During the stabilization of cultivated media waste, temperature decreased and pH increased on the 15th day, and the germination index was 88 after the period, indicating that at least 15 days of stabilization is needed when cultivated media waste is used for growth material of crop. As for germination characteristics, when the mixture rate of cultivated media waste was 20% and under, germination of cucumber and oriental melon was favorable without difference compared to the control plots. For lettuce and Chinese cabbage, no statistically significant difference was found when the rate was 10% and under compared to the control plots. As for seedling quality after 20 days of sowing, cucumber, oriental melon, and Chinese cabbage showed favorable growth only when the mixture rate of cultivated media waste was 10% and under; lettuce showed lower growth characteristics regardless of mixture rate when compared to the control plots. Cultivated media waste may be significantly useful for cucumber and oriental melon, but not for Chinese cabbage and lettuce.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.6
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• pp.682-688
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• 2016

Food waste has recognized one of useful sources for potentially agricultural application to supply organic matter and nutrients in arable soil. However, there was little information on application of food waste compost related to the maturity and NaCl content in arable soil. This study evaluated the effect of food waste compost application on yield and fertility in soil under flooding and upland condition. The yields in rice and pepper cultivation decreased with increasing the rate of food waste compost application in soil (p<0.05). Maximum yields of rice ($49.0g\;plant^{-1}$) and pepper ($204g\;plant^{-1}$) were shown at 10 and $30Mg\;ha^{-1}$ of food waste compost application, respectively. The N, P, and K contents in grain and plant residues increased by the application of food waste compost, there was no difference on Na/K ratio in plant tissue among the treatments. Application of food waste compost resulted in the increase of pH, EC, TC, available P contents in soil after crop harvest, especially, which was shown the increase of the CEC and exchangeable sodium percentage (ESP) contents in irrespective of water condition. In conclusion, application of food waste compost in soil was effective on the supply of the organic matter and nutrient. However, it might need caution to apply food waste compost for sustainable productivity in arable soil because of potential Na accumulation.

• Journal of the Korea Organic Resources Recycling Association
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• v.24 no.2
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• pp.51-58
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• 2016

In the Integrated Two-Phase Anaerobic Digestion (ITPAD) process, acid and methane fermentation take place in one reactor, which has advantages to cope with organic load variation and reduce foot-print required, compensating disadvantages of Conventional Separated Two-Phase Anaerobic Digestion (CSTPAD). In the present work, organic matter degradation efficiency and biogas generation amount and other performance parameters of the ITPAD fed with food waste leachate were analyzed. In addition, feasibility study on the ITPAD method was performed by comparing its digestion efficiency with that of the CSTPAD. Organic matter alteration and biogas generation of the integrated method were examined for approximately 130 days based on the 5ton/day scaled pilot plant. Experiment results revealed that organic matter removal rate was 80% for mean food waste leachate input amount of $4.1m^3/day$. The biogas generation rate was $63.0m^3$ per ton of food waste leachate input, corresponding to the input VS amount of $0.724m^3/kg-VS_{added}$, and methane content of generated biogas was approximately 61.3%. The ITPAD has a comparable or higher organic matter removal efficiency compared to the conventional separated two-phase anaerobic digestion method. Consequently, the ITPAD method has a great need to commercialize a food waste leachate treatment technology against highly concentrated organic waste leachate.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.193-204
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• 2020

This experiment was conducted to study the effect of organic fertilizer on the growth of Peucedanum japonicum Thunberg and the change of soil chemical characteristics. The organic matter contents of coffee sludge and dried food waste powder were 44.26 and 51.18%, respectively. These values exceed the organic matter content of organic fertilizers recommended by the Rural Development Administration (RDA) of South Korea by more than 30%. Accordingly, they indicate the possibility of their use as organic fertilizers. The results from the analysis of soil properties after cultivation showed that the organic matter content of coffee sludge amended soils was two-fold higher than that of dried food waste powder amended soils. However, the content of available phosphorus was two times lower in the coffee sludge amendments. It is expected that the dried food waste powder was actively used to decompose organic substances, and that phosphoric acid was added by the soil microorganisms used to decompose organic substances. In terms of Peucedanum japonicum Thunberg growth, leaf discoloration was observed for all treatments except with the standard rate of dried food waste powder. The standard rate of dried food waste powder also produced relatively better results than other treatments with regard to other growth characteristics such as root length (34.08 cm), root diameter (0.78 cm), and fresh root weight (4.77 g plant^-1). Therefore, the standard rate of dried food waste powder produced better results than other treatments and can be used as an organic fertilizer in the growth of Peucedanum japonicum Thunberg.

• Korean Journal of Organic Agriculture
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• v.26 no.3
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• pp.369-379
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• 2018

This study examines consumers' perception of agricultural products using nuclear power plants waste heat. This study surveyed 348 consumers and found that presenting information about safety of waste heat utilization increased appropriacy of waste heat; after providing the information, the percentage of respondents in favor of using waste heat increased 27.5% point from 38.3% to 65.8%. The most important reason against using waste heat was because it threatened the safety of agricultural products, and the most important reason for its support was to reduce farm production costs. The purchase intention for agricultural products using waste heat had risen by at least 10% point after providing the information about safety of waste heat. Those means that it important provision of accurate and reliable information on the safety of waste heat to encourage the utilization of waste heat from nuclear power plants. Purchase intention for flowers using waste heat was most, followed by vegetables, fruits (including fruits and vegetables).

• The Korean Journal of Pesticide Science
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• v.19 no.4
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• pp.402-410
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• 2015

The purpose of this study was to estimate the chitinolytic and antifungal activity of Actinomycetes sp.isolated from waste mushroom media. In five kinds of waste mushroom media, Sinyeong mushroom and Yangsongi were the order of the population density of actinomycetes. Totally 91 chitinolytic isolates of Actinomycetes sp. were obtained from waste mushroom media. The isolates were categorized into 3 groups based on chitinolytic activity and antagonisms against Phytophthora capsici, Rhizoctonia solani, Sclerotinia sclerotiorum, Collectotrichum gloeosporioides, and Cladosporium cucumerinum in vitro. CA-23 was selected as a representative isolate of a group showing strong chitinolytic and antagonistic activities to all of the plant pathogens, while AA-65 was selected as a representative isolate showing no chitinolytic activities but strong antagonistic activities to the pathogens. CA-23 and AA-65 were highly effective on control of Phytophthora blight of hot-pepper, powdery mildew and scab of cucumber in a greenhouse tests. Among the isolates tested, CA-23 showed highest control efficacy, while AA-65 not only effectively controlled the diseases but also consistently increased plant growth and yield. Although the isolates are similarly affected on suppression of plant pathogens, the isolates could be differ from each other in modes of action. Further studies on mechanisms and practical applications are being progressed.