• Journal of Korean Society of Environmental Engineers
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• v.37 no.5
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• pp.253-261
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• 2015

In this study, Chlorophyll-a (chl-a) prediction model and multiple parameters affecting algae occurrence in Mulgeum site were evaluated by statistical analysis using water quality, hydraulic and climate data at Mulgeum site (1998~2008). Before the analysis, control chart method and effect period of typhoon were adopted for improving reliability of the data. After data preprocessing step two methods were used in this study. In method 1, chl-a prediction model was developed using preprocessed data. Another model was developed by Method 2 using significant parameters affecting chl-a after data preprocessing step. As a result of correlation analysis, water temperature, pH, DO, BOD, COD, T-N, $NO_3-N$, $PO_4-P$, flow rate, flow velocity and water depth were revealed as significant multiple parameters affecting chl-a concentration. Chl-a prediction model from Method 1 and 2 showed high $R^2$ value with 0.799 and 0.790 respectively. Validation for each prediction model was conducted with the data from 2009 to 2010. Training period and validation period of Method 1 showed 20.912 and 24.423 respectively. And Method 2 showed 21.422 and 26.277 in each period. Especially BOD, DO and $PO_4-P$ played important role in both model. So it is considered that analysis of algae occurrence at Mulgeum site need to focus on BOD, DO and $PO_4-P$.

• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.1
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• pp.19-27
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• 2021

Hydroponic farming is a method to grow a plant without soil. Plants can be grown on water or hydroponic growing media, and they are fed with mineral nutrient solutions, which are fertilizers dissolved into water. Hydroponic farming has the advantage of increasing plant productivity over conventional greenhouse farming. Previous studies of hydroponic nutrient wastewater from acyclic hydroponic farms pointed out that hydroponic nutrient wastewater contained residual nutrients, and they were drained to a nearby river bank which causes several environmental issues. Also, previous studies suggest that excessive use of the nutrient solution and disposal of used hydroponic growing media and crop wastes in hydroponic farms are major problems to hydroponic farming. This study was conducted to determine the impact of hydroponic nutrient wastewater, used hydroponic growing media, and crop wastes from acyclic hydroponic farms on the surrounding environment by analyzing water quality and soil analysis of the above three factors. Three soil cultivation farms and several hydroponic farms in the Gangwon C region were selected for this study. Samples of water and soils were collected from both inside and outside of each farm. Also, a sample of soil and leachate from crop waste piles stacked near the farm was collected for analysis. Hydroponic nutrient wastewater from acyclic hydroponic farm contained an average of 402 mg/L of total nitrogen (TN) concentration, and 77.4 mg/L of total phosphate (TP) concentration. The result of TP in hydroponic nutrient wastewater exceeds the living environmental standard of the river in enforcement decree of the framework act on environmental policy by 993.7 times. Also, it exceeds the standard of industrial wastewater discharge standards under the water environment conservation act by 6~19 times in TN, and 2~27 times in TP. Leachate from crop waste piles contained 11,828 times higher COD and 395~2662 times higher TP than the standard set by the living environmental standard of the river in enforcement decree of the framework act on environmental policy and exceeds 778 times higher TN and 5 times higher TP than the standard of industrial wastewater discharge standards under the water environment conservation act. For more precise studies of the impact of hydroponic nutrient wastewater, used hydroponic growing media, and crop wastes from acyclic hydroponic farms on the surrounding environment, additional information regarding a number of hydroponic farms, arable area(ha), hydroponic farming area, seasonal, weather, climate factor around the river, and the property of the area and farm is needed. Analysis of these factors and additional water and soil samples are needed for future studies.

• Clean Technology
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• v.28 no.1
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• pp.63-78
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• 2022

Electronics industrial wastewater treatment facilities release organic wastewaters containing high concentrations of organic pollutants and more than 20 toxic non-biodegradable pollutants. One of the major challenges of the fourth industrial revolution era for the electronics industry is how to treat electronics industrial wastewater efficiently. Therefore, it is necessary to develop an electronics industrial wastewater modeling technique that can evaluate the removal efficiency of organic pollutants, such as chemical oxygen demand (COD), total nitrogen (TN), total phosphorous (TP), and tetramethylammonium hydroxide (TMAH), by digital twinning an electronics industrial organic wastewater treatment facility in a cyber physical system (CPS). In this study, an electronics industrial wastewater activated sludge model (e-ASM) was developed based on the theoretical reaction rates for the removal mechanisms of electronics industrial wastewater considering the growth and decay of micro-organisms. The developed e-ASM can model complex biological removal mechanisms, such as the inhibition of nitrification micro-organisms by non-biodegradable organic pollutants including TMAH, as well as the oxidation, nitrification, and denitrification processes. The proposed e-ASM can be implemented as a Water Digital Twin for real electronics industrial wastewater treatment systems and be utilized for process modeling, effluent quality prediction, process selection, and design efficiency across varying influent characteristics on a CPS.

• Clean Technology
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• v.28 no.1
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• pp.79-93
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• 2022

In this study, an electronics industrial wastewater activated sludge model (e-ASM) to be used as a Water Digital Twin was calibrated based on real high-tech electronics industrial wastewater treatment measurements from lab-scale and pilot-scale reactors, and examined for its treatment performance, effluent quality prediction, and optimal process selection. For specialized modeling of a high-tech electronics industrial wastewater treatment system, the kinetic parameters of the e-ASM were identified by a sensitivity analysis and calibrated by the multiple response surface method (MRS). The calibrated e-ASM showed a high compatibility of more than 90% with the experimental data from the lab-scale and pilot-scale processes. Four electronics industrial wastewater treatment processes-MLE, A2/O, 4-stage MLE-MBR, and Bardenpo-MBR-were implemented with the proposed Water Digital Twin to compare their removal efficiencies according to various electronics industrial wastewater characteristics. Bardenpo-MBR stably removed more than 90% of the chemical oxygen demand (COD) and showed the highest nitrogen removal efficiency. Furthermore, a high concentration of 1,800 mg L^-1 T MAH influent could be 98% removed when the HRT of the Bardenpho-MBR process was more than 3 days. Hence, it is expected that the e-ASM in this study can be used as a Water Digital Twin platform with high compatibility in a variety of situations, including plant optimization, Water AI, and the selection of best available technology (BAT) for a sustainable high-tech electronics industry.

• Journal of the Korean Society of Marine Environment & Safety
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• v.22 no.6
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• pp.723-730
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• 2016

Domestic Manila clam production has been reduced due to coastline changes and environmental degradation, but aquaculture industry is facing difficulties caused by an increase in imports. It is important to recognize the integral habitat environment in order to do sustainable aquaculture. The habitat environment of Manila clams (Ruditapes philippinarum) is closely related to the productivity of aquaculture farms. This study investigated 3 indexes, survival (sediment type, hydrodynamic), growth (Chlorophyll a, DIN, DIP) and environment (water temperature, dissolved oxygen, sediment chemical oxygen demand, ignition loss) as indicators of habitat characteristics for a tidal flat farm in Geunso Bay (Pado and Beopsan) from June 2015 to May 2016. As a result, Pado (maximums.; sand 48.76 %, hydrodynamic 10.59 cm/s, Chlorophyll a 12.70 ug/L, exposure time 3 hours, DO 18.65 mg/L) had a higher sand content, faster current speed, more abundant nutrients and DO, providing more favorable conditions for Manila clams than Beopsan (maximums.; sand 37.40 %, hydrodynamic 6.02 cm/s, Chlorophyll a 6.41 ug/L, exposure time 7 hour, DO 14.81 mg/L). In fact, Pado showed a higher density than Beopsan. This study considered the habitat environments of Pado and Beopsan to provide a basis for optimal management practices and potential suitable sites in Geunso bay.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.3
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• pp.132-137
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• 2008

The average concentrations of COD and copper in the livestock sludge are $930,726{\pm}380.801$ mg/kg and $679{\pm}341$ mg/kg, respectively. Due to the high concentrations, dumping to the sea of the sludge could pose potential adverse effects to the marine environment. On the contrary, it could have economic advantages on land as the energy of biogas generated by decomposition of organisms and the compost in case of the sludge of good quality with the abundant nitrogen and phosphorus. Nevertheless, the amount of livestock sludge dumped to the sea in Korea increased sharply from 51,000 $m^3$ in 1997 to 2,745,000 $m^3$ in 2005. And also it had the high proportion of 27% in total amount of waste dumped into the sea (7,451,000 $m^3$) in 2007. It might cost between 20,000 won and 33,000 won to dump to the sea of the sludge. In comparison, it might cost 20,000 won to com- post the sludge. And its purification treatment even might cost just 10,000 won. It means that the disposal of the sludge at sea is the most expensive method to deal with the sludge, but ranchers, who engage in the livestock industry, still prefer the disposal at sea to the other methods on land such as the compost and purification treatment. In this article, therefore, we would analyze various factors in the ranchers' preference for the disposal of the sludge at sea, and then we could suggest some legal improvements to prevent and reduce pollution of the sea.

• Journal of the Korea Organic Resources Recycling Association
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• v.23 no.2
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• pp.53-60
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• 2015

Newly, nutrients recovery by bioconversion in the swine waste which caused serious problems due to its high organic fraction and content of nutrients such as phosphorus and nitrogen is viewed as a considerable approach since it produces valuable product as well as recycling of resources. Consequently, it is necessary to find new methods to treat swine waste. One possible solution to this problem is to use this potential pollutant as a growth substrate for economically valuable products. The study for the fundamental improvement of bioconversion efficiency by finding optimum growth conditions using statistical models and biotechnology was performed. A novel approach to utilize swine waste by cultivating mycelia of the mushroom Phellinus linteus are described. A central composite face-centered design (CCF) for the experiments was used to develop empirical model providing a quantitative interpretation of the relationships among the three variables, which were substrate concentration, pH, and temperature. The maximal radial extension rate (2.78mm/d) of P.linteus was determined under the condition of 5.0 g COD/L, pH 5.0, and temperature $29.7^{\circ}C$. The results of this study suggest that swine waste could be utilized as a growth substrate for the cultivation of mushroom mycelia enhancing an efficiency of utilizing this by-product of the livestock industry.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.5
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• pp.903-915
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• 2011

Recently, anaerobic methane production of agricultural waste biomass has received increasing attention. Until now domestic BMP (Biochemical methane potential) studies concerned with agricultural waste biomass have concentrated on the several waste biomass such as livestock manure, food waste, and sewage sludge from WWTP (Waste water treatment plant). Especially, the lack of standardization study of BMP assay method has caused the confused comprehension and interpretation in the comparison of BMP results from various researchers. Germany and USA had established the standard methods, VDI 4630 and ASTM E2170-01, for the analysis of BMP and anaerobic organic degradation, respectively. In this review, BMP was defined in the aspect of organic material represented as COD (Chemical oxygen demand) and VS (Volatile solid), and the influence of several parameters on the methane potential of the feedstock was presented. In the investigation of domestic BMP case studies, BMP results of 18 biomass species generating from agriculture and agro-industry were presented. And BMP results of crop species reported from foreign case studies were presented according to the classification system of crops such as food crop, vegetables, oil seed and specialty crop, orchards, and fodder and energy crop. This review emphasizes the urgent need for characterizing the innumerable kind of biomass by their capability on methane production.

• The Korean Journal of Malacology
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• v.19 no.2
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• pp.161-169
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• 2003

Seawater and sediment quality analysed was calculated to examinate the present environmental characteristics and pollution load was also calculated to evaluate the effect of farming area on the coastal environment. The measurements for seawater quality demonstrate the coastal environment has relatively eutrophicated with significantly decreased DO (0.2-8.5 mg/l) and elevated COD (9.6-31.2 mg/l) in summer. It was also evident that the water quality in Jindong Bay has been influenced by residues tide from Masan Bay with high metal concentration in August of 2002. Annual total pollution load (land and farm-driven) was estimated at 37,316 ton (SS) /yr: 9,809 ton/yr (26.3%) of land-driven load, 23,576 ton/yr (63.2%) of coastal sedimentation and 3,932 ton/yr (10.5%) of feces of cultural organisms. When all ark shell seedling farms are permitted species conversion to ascidian farm, the pollution load would increase by 196%, which may be another source for accelerating the eutrophication of the environment in Jindong Bay.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.25-31
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• 2009

In the present study, three types of teriyaki sauce were prepared using chicken bone and eel bone, which are commonly used as the primary ingredient of teriyaki sauce, as well as codfish bone, which has various functions. The and analyzed their quality characteristics of the different types of teriyaki sauce were then compared through physiochemical and sensory evaluation. The results of this study were as follows. The water content was lowest and the ash content was highest in teriyaki sauce that was prepared using chicken bone as the primary ingredient. In addition, the Ca, K, Mg, Na and P content were highest in the teriyaki sauce that was prepared using chicken bone as the primary ingredient. The total free amino acid content was highest in teriyaki sauce prepared using chicken bone, followed by sauces prepared using codfish bone and eel bone. The levels of free amino acids evaluated in this study occurred in the following order for all teriyaki sauces: glutamic acid > aspartic acid > leucine. When the sensory evaluation was conducted, teriyaki sauce prepared using chicken bone as the main ingredient was found to be best, followed by sauce prepared using codfish bone in terms of palatability and viscosity among descriptive scales, and smell and general preference among hedonic scales. The results of this study suggest that teriyaki sauce could be produced using codfish bone instead of chicken bone, which would enable production of a high value-added product through the use of a common byproduct. This would result in the efficient use of unused resources, prevention of environmental pollution and supply of an inexpensive that could be widely used in the food processing and food service industries.