• Environmental Engineering Research
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• v.24 no.4
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• pp.662-669
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• 2019

Anaerobic digestion is a popular sewage sludge (Ss) treatment method as it provides significant pollution control and energy recovery. However, the low C/N ratio and poor biodegradability of Ss necessitate pretreatment methods that improve solubilization under anaerobic conditions in addition to anaerobic co-digestion with other substrates to improve the process efficiency. In this study, three pretreatment methods, namely microwave irradiation, ultrasonication, and heat treatment, were investigated, and the corresponding improvement in methane production was assessed. Additionally, the simplex centroid design method was utilized to determine the optimum mixture ratio of food waste (Fw), livestock manure (Lm), and Ss for maximum methane yield. Microwave irradiation at 700 W for 6 min yielded the highest biodegradability (62.0%), solubilization efficiency (59.7%), and methane production (329 mL/g VS). The optimum mixture ratio following pretreatment was 61.3% pretreated Ss, 28.6% Fw, and 10.1% Lm. The optimum mixture ratio without pretreatment was 33.6% un-pretreated Ss, 46.0% Fw, and 20.4% Lm. These results indicate that the choice of pretreatment method plays an important role in efficient anaerobic digestion and can be applied in operational plants to enhance methane production. Co-digestion of Ss with Fw and Lm was also beneficial.

• Korean Journal of Soil Science and Fertilizer
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• v.47 no.3
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• pp.187-190
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• 2014

The agricultural policy/Environmental eXtender (APEX) model was developed by the Blackland Research and Extension Center in Temple, Texas. APEX is a flexible and dynamic tool that is capable of simulating a wide array of management practices, cropping systems, and other land uses across a broad range of agricultural landscapes, including whole farms and small watersheds. The model can be configured for novel land management strategies, such as filter strip impacts on pollutant losses from upslope crop fields, vegetated grassed waterways in combination with filter strip impacts, and land application of manure removed from livestock feedlots or waste storage ponds. The APEX model has continually evolved since its inception, and the process of adaptation and modification will likely continue as use of the model expands for an ever-increasing range of environmental problems and conditions. Several improvements to specific model subroutines have already been initiated, while other potential improvements have been identified that will require future research and code modification efforts.

• Journal of Life Science
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• v.21 no.12
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• pp.1716-1720
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• 2011

A bacterium hydrolysing various organic materials including cellulose, protein, starch and lipid was isolated. The isolate was identified as Bacillus subtilis, and named Bacillus subtilis CK-2 in this paper. This bacterium showed optimal growth at $40\sim45^{\circ}C$, pH 6~9, and 0~3% of NaCl. B. subtilis CK-2 seemed to synthesis highly active autolysin. The hydrolytic enzymes produced by B. subtilis CK-2 were primary enzymes because extracellular enzyme activities varied similarly to the growth curve. The hydrolytic enzymes seemed to be stable at basic pH conditions. From these results, B. subtilis CK-2 was found to bea useful bacterial agent for composting, or for use in feed-production waste in agriculture, fishery, forest materials, livestock farming, and food.

• Journal of the Korea Organic Resources Recycling Association
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• v.27 no.1
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• pp.57-64
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• 2019

We investigated influence of connected influent on the treatability of a wastewater treatment plant (WWTP), recently accepting effluent from a sludge carbonization facility. Based upon the pollutant loading rates (kg/d) of each connected influent, food waste leachate and livestock wastewater contributed to high BOD and COD loadings, while sludge carbonization facility effluent certainly contributed to T-N and $NH_3-N$ loadings. The nitrification rate in aerobic tank decreased to 55% with the carbonization facility effluent entering to the WWTP, while it was 89% with no carbonization facility effluent entering. The sludge carbonization facility effluent may need to be pretreated to reduce T-N and $NH_3-N$ loadings before entering to the WWTP for further treatment.

• Geophysics and Geophysical Exploration
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• v.21 no.4
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• pp.244-254
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• 2018

The first geophysical technique applied to the agricultural sector in Korea was electrical resistivity sounding and conducted in purpose of groundwater exploitation in the 1970s. According to the diversity of agricultural activities since the 1990s, various geophysical methods including electrical resistivity, electromagnetic induction, and self-potential method were applied to several agricultural fields such as soil characterization with saline concentration in vast reclaimed area, delineation of seawater intrusion regions in costal aquifer, safety inspection of embankment dikes with leakage problem, detection of ground subsidence from overpumping and tracing of groundwater aquifer contamination by leachate from livestock mortality burial or waste burial site. This paper introduces representative geophysical techniques that have been utilized in various agricultural fields and suggests several ways to develop the geophysical methods required for the precision agriculture field in the near future based on the past achievements.

• Journal of Korean Society of Water and Wastewater
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• v.33 no.2
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• pp.141-150
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• 2019

Total organic carbon(TOC) was introduced as the water quality index of the rivers and lakes in 2013. This paper evaluated factors affecting effluent TOC concentrations and treated and discharged loads of existing publicly owned treatment works(POTWs). For selected POTWs with greater treatment capacity than $500m^3/day$, factorial analysis was used to consider effects of kinds of biological treatment processes, inflow of other types of wastewater(industrial, livestock, landfill leachate wastewater, etc.) with domestic wastewater, sewer separation rate, and effluent discharging zones in which different effluent criteria applied. As a result, those factors did not show significant effect on effluent TOC concentration of POTWs in effluent discharging zone I and II. However, In effluent discharging zone III and IV, kinds of biological treatment processes, the inclusion of other waste in influent of domestic wastewater, and the sewer separation rate were significant factors. The treated TOC load in POTWs was also not affected significantly by the variables set in this study. On the other hand, those three factors influenced significantly on the TOC load discharged to water bodies. The sum of factorial effects and the contribution rate of three factors to the discharged TOC load was 60.23 and 41%, 59.57 and 41%, and 42.04 and 18%, respectively.

• Journal of Wetlands Research
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• v.23 no.1
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• pp.7-13
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• 2021

Due to rapid industrial development, population growth, and improvement of living standards, the amount of sewage and wastewater, including nutrients, is increasing every year. In addition to the increasing amount of sewage and wastewater generation, untreated linked treated water (manure, livestock manure, industrial wastewater, leachate, food waste) is also increasing, and many of the linked treated water flows directly into nearby sewage treatment plants. The associated treated water causes many problems because of its own characteristics, low flow rate with high concentration compared to existing inflow sewage. In order to solve this problem, it is necessary to investigate the quantity and quality of the connected treated water whichh is flowed into the sewage treatment plant, and a study the effect on sewage treatment. Therefore, in this paper, we would like to examine the effect of the linked treated water. Seasonal effect associated with water pollution conditions was considered. In addition, a scenario was created through the distribution and inflow of connected treated water along with the water temperature conditions. Through scenario analysis, we intend to optimize the operating conditions of linked processing.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.6
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• pp.1-12
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• 2022

Estuary reservoirs were artificial reservoir with seawalls built at the exit points of rivers. Although many water resources can be saved, it is difficult to manage due to the large influx of pollutants. To manage this, it is necessary to analyze watersheds and reservoirs through accurate modeling. Therefore, in this study, we linked the Hydrological Simulation Program-FORTRAN (HSPF), Environmental Fluid Dynamics Code (EFDC), and Water quality Analysis Simulation Program (WASP) models to simulate the hydrology and water quality of the watershed and the water level and quality of estuary lakes. As a result of applying the linked model in stream, R² 0.7 or more was satisfied for the watershed runoff except for one point. In addition, the water quality satisfies all within 15% of PBIAS. In reservoir, R² 0.72 was satisfied for water level and the water quality was within 15% of T-N and T-P. Through the modeling system, We applied upstream pollutant management scenarios to analyze changes in water quality in estuary reservoirs. Three pollution source management were applied as scenarios, the improvement of effluent water quality from the sewage treatment plant and the livestock waste treatment plant was effective in improving the quality of the reservoir water, while the artificial wetland had little effect. Water quality improvement was confirmed as a measure against upstream pollutants, but it was insufficient to achieve agricultural water quality, so additional reservoir management is required.

• Korean Journal of Veterinary Service
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• v.45 no.4
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• pp.277-284
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• 2022

Salmonella is a pathogenic bacterium that has long been important industrially because it has a wide host range and can be transmitted to humans through direct contact as well as indirect contact such as food contaminated with animal waste. Understanding how to reduce Salmonella contamination in pig farms is important for public health and the livestock industry from an economic perspective. In the swine industry, high concentrations of disinfectants have been applied because it is difficult to effectively control Salmonella in environments contaminated with organic substances. In order to evaluate the synergetic effect of disinfectants, the efficacy of two commercial disinfectants diluted in hard water and microbubble water (MBW) were compared under the laboratory condition. Different concentrations of both disinfectants combined with 1% detergent diluted in the two diluents were evaluated for their antibacterial effect. In the case of monopersulfate-based disinfectant groups, the growth of Salmonella was not observed at 1:200 dilution with both the hard water and MBW combined with 1% detergent. In the case of citric acid-based disinfectant, the bacterial growth was not observed at 1:800 dilution with MBW combined with 1% detergent. Our results show that the use of MBW as a diluent might improve the biological activities of acid-based disinfectant.

• Journal of the Korean Institute of Rural Architecture
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• v.26 no.2
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• pp.37-46
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• 2024

The city is developing into a smart city. Smart villages and smart farms are developing in rural areas. Architectural technology needs synergy with smart cities, smart villages, and smart factories (intelligent factories) to help architectural experts understand smart farms and build facilities and equipment. Smart farms require design and construction technology with architectural structure and function. The purpose of this study was to investigate the current status and cases of smart farms in Korea and to investigate cases abroad. The conclusion is as follows. ① Smart farms are developing rapidly. The Korean government is expanding smart farms by utilizing ICT technology and infrastructure. ② 'Smart Farm Innovation Valley', which has been promoted since 2018, is a cutting-edge convergence cluster industrial complex that integrates production, education, and research functions such as start-ups and technological innovation. ③ In domestic cases, smart farms are operated in subway stations, buildings, supermarkets, and restaurants. ④ In the Japanese case, a dome-type smart farm was being operated. It utilized factory wastewater, waste heat, renewable energy, and used new materials. Otemachi Ranch raised livestock and provided a lounge on the 13th floor of the building. ⑤ In the cases of Korea and Japan, the smart farm technology is very similar. As stated earlier, since the food culture and agricultural technology of both countries are similar, we hope to promote the development of smart farms that can reduce concerns about future food by communicating and sharing mutual technologies.