Pub Date : 2023-01-31DOI: 10.4491/ksee.2023.45.1.11
In-Ha Choi, Kyeong-Hwan Cha, Kyung-Min Kim, Johng-Hwa Ahn
Objectives:The purpose of this study is to compare single models according to the missing value handling techniques for predicting leachate generation.Methods:Input factors such as landfill gas generation, and weather data (precipitation, wind speed, radiation, temperature, and relative humidity) were used from June 2002 to October 2018. Linear interpolation and mean method were used as the missing value handling technique. The experiment was conducted by dividing the data into train and test data according to the optimal ratio. Various single models were used, and the prediction performance of the model was compared and evaluated using coefficient of determination (R2).Results and Discussion:The gated recurrent unit (GRU) model was the best among the single models. In the GRU model, R2 was 0.867 for linear interpolation and R2 was 0.839 for the mean method, so that the GRU model using linear interpolation was most suitable for predicting leachate generation. In the ANN model, R2 of linear interpolation (0.862) was higher than that of mean method (0.828). In the long short-term memory (LSTM) model, R2 was 0.779 for linear interpolation and 0.762 for mean method. In the random forest (RF) model, R2 for linear interpolation (0.700) was also higher than that for the mean method (0.665). The model performance was excellent in the order GRU>ANN>LSTM>RF. The linear interpolation for the missing value handling technique was superior to the mean method in all models used in this experiment.Conclusion:The GRU using linear interpolation was the most suitable model for predicting landfill leachate generation.
{"title":"Development of Forecasting Model for Machine Learning-Based Landfill Leachate Generation Using Linear Interpolation","authors":"In-Ha Choi, Kyeong-Hwan Cha, Kyung-Min Kim, Johng-Hwa Ahn","doi":"10.4491/ksee.2023.45.1.11","DOIUrl":"https://doi.org/10.4491/ksee.2023.45.1.11","url":null,"abstract":"Objectives:The purpose of this study is to compare single models according to the missing value handling techniques for predicting leachate generation.Methods:Input factors such as landfill gas generation, and weather data (precipitation, wind speed, radiation, temperature, and relative humidity) were used from June 2002 to October 2018. Linear interpolation and mean method were used as the missing value handling technique. The experiment was conducted by dividing the data into train and test data according to the optimal ratio. Various single models were used, and the prediction performance of the model was compared and evaluated using coefficient of determination (R2).Results and Discussion:The gated recurrent unit (GRU) model was the best among the single models. In the GRU model, R2 was 0.867 for linear interpolation and R2 was 0.839 for the mean method, so that the GRU model using linear interpolation was most suitable for predicting leachate generation. In the ANN model, R2 of linear interpolation (0.862) was higher than that of mean method (0.828). In the long short-term memory (LSTM) model, R2 was 0.779 for linear interpolation and 0.762 for mean method. In the random forest (RF) model, R2 for linear interpolation (0.700) was also higher than that for the mean method (0.665). The model performance was excellent in the order GRU>ANN>LSTM>RF. The linear interpolation for the missing value handling technique was superior to the mean method in all models used in this experiment.Conclusion:The GRU using linear interpolation was the most suitable model for predicting landfill leachate generation.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43455442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-31DOI: 10.4491/ksee.2023.45.1.21
Im-Joo Choi, Dongwook Lee, Kyung-hak Tak, Jeong-Hui Jo
Objectives:The purpose of this study is to provide basic data so that the emission sources of industrial complexes can be effectively managed through a characteristic study of hazardous air pollutants in residential areas adjacent to the national industrial complex in Ulsan.Methods:In Yaeum-dong, a residential area near the industrial complex, SIFT-MS, which enables real-time continuous measurement, was used to identify the characteristics of VOCs and odorous substances.Results and Discussion:When looking at the concentrations by chemical substance group, aliphatic hydrocarbons accounted for a significant portion, showing different characteristics from other large cities. This indicates that the Yaeum-dong area is directly affected by the emission source of the nearby petrochemical complex. As an individual substance, ammonia showed the highest concentration among HAPs. Seasonal HAPs concentrations generally tended to be high in summer and low in winter. When examining concentrations by time of day, it showed characteristics of industrial areas affected by VOCs scattered and volatilized in national industrial complexes. In addition, it was confirmed that the characteristics of urban areas appearing in general metropolitan traffic congestion zones appeared at the same time. Compared with the results of other previous studies, in general, there was no significant difference in concentrations from the results of measurements in residential areas near petrochemical complexes. And it showed a much lower concentrations than the measured value in industrial complex. As a result of CPF analysis for estimating the source of pollutants, most HAPs showed high concentrations in the south wind direction, indicating that the measurement point was affected by the industrial complex.Conclusion:As a result of the study on the characteristics of HAPs in residential areas near the industrial complex, it can be estimated that both characteristics appear in industrial and urban areas.
{"title":"A study on the Characteristics of HAPs in Residential areas affected by Industrial Complex using SIFT-MS","authors":"Im-Joo Choi, Dongwook Lee, Kyung-hak Tak, Jeong-Hui Jo","doi":"10.4491/ksee.2023.45.1.21","DOIUrl":"https://doi.org/10.4491/ksee.2023.45.1.21","url":null,"abstract":"Objectives:The purpose of this study is to provide basic data so that the emission sources of industrial complexes can be effectively managed through a characteristic study of hazardous air pollutants in residential areas adjacent to the national industrial complex in Ulsan.Methods:In Yaeum-dong, a residential area near the industrial complex, SIFT-MS, which enables real-time continuous measurement, was used to identify the characteristics of VOCs and odorous substances.Results and Discussion:When looking at the concentrations by chemical substance group, aliphatic hydrocarbons accounted for a significant portion, showing different characteristics from other large cities. This indicates that the Yaeum-dong area is directly affected by the emission source of the nearby petrochemical complex. As an individual substance, ammonia showed the highest concentration among HAPs. Seasonal HAPs concentrations generally tended to be high in summer and low in winter. When examining concentrations by time of day, it showed characteristics of industrial areas affected by VOCs scattered and volatilized in national industrial complexes. In addition, it was confirmed that the characteristics of urban areas appearing in general metropolitan traffic congestion zones appeared at the same time. Compared with the results of other previous studies, in general, there was no significant difference in concentrations from the results of measurements in residential areas near petrochemical complexes. And it showed a much lower concentrations than the measured value in industrial complex. As a result of CPF analysis for estimating the source of pollutants, most HAPs showed high concentrations in the south wind direction, indicating that the measurement point was affected by the industrial complex.Conclusion:As a result of the study on the characteristics of HAPs in residential areas near the industrial complex, it can be estimated that both characteristics appear in industrial and urban areas.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47467462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-01-31DOI: 10.4491/ksee.2023.45.1.1
Junyeong Jeon, J. Jeon, S. Shin, Younki Lee
Objectives : The thermal stability of halloysite and magnesium silicate is discussed in terms of microstructural change and adsorption behavior to optimize their composite as an absorbent for methylene blue (MB) and heavy metal ions removal from an aqueous solution.Methods : Halloysite-magnesium silicate tubular composites with high adsorption capacity of methylene blue and heavy metal ions were prepared with extrusion and consequent firing. To define the firing temperature of the tubular media, the microstructure and the adsorption equilibrium characterized the thermal stability of halloysite and magnesium silicateResults and Discussion : The magnesium silicate used in this study shows broad peaks in x-ray diffraction; however, the treatment of 750℃ induces its crystallization. The specific surface area of the magnesium silicate is also gradually decreased along with the firing temperature increase. No significant degradation in methylene blue adsorption capacity for magnesium silicate is observed until 500℃-treatment. However, the higher firing temperature reduces the capacity: 6.9%P, 27.3%P, and 91.2%P decrease for 600℃, 700℃, and 750℃, respectively. Regardless of heat treatment, the Langmuir isotherm equation represents the adsorption equilibria well compared to the Freundlich model. The tubular media of the halloysite – 30 wt% of magnesium silicate fired at 600℃ exhibits a high specific surface area of 115 m2 g-1 and a relative porosity of 43.5%. Compared to the halloysite-only tubular media, the adsorption capacity of the composites is significantly improved with the incorporation of magnesium silicate. The adsorption capacity of 168h for methylene blue is more than tripled, 29.8 mg g-1, and the adsorption capacity of Cr(III), Cu(II), and Zn(II) is also greatly enhanced by more than 4.8 times.Conclusion : The thermal stability of magnesium silicate is investigated for use as an additive adsorbent in terms of the microstructure and the adsorption capacity. Even at 600℃ of the firing temperature, magnesium silicate shows a higher specific surface area and higher adsorption capacity of MB compared to those of the halloysite; the adsorption fits well into Langmuir behavior. The addition of magnesium silicate into the halloysite media significantly enhances its adsorption capacity for MB and heavy metal ions such as Cr(III), Cu(II), and Zn(II).
{"title":"Halloysite-Magnesium Silicate Composites as Adsorbent for Removal of Methylene Blue and Heavy Metals from Aqueous Solution","authors":"Junyeong Jeon, J. Jeon, S. Shin, Younki Lee","doi":"10.4491/ksee.2023.45.1.1","DOIUrl":"https://doi.org/10.4491/ksee.2023.45.1.1","url":null,"abstract":"Objectives : The thermal stability of halloysite and magnesium silicate is discussed in terms of microstructural change and adsorption behavior to optimize their composite as an absorbent for methylene blue (MB) and heavy metal ions removal from an aqueous solution.Methods : Halloysite-magnesium silicate tubular composites with high adsorption capacity of methylene blue and heavy metal ions were prepared with extrusion and consequent firing. To define the firing temperature of the tubular media, the microstructure and the adsorption equilibrium characterized the thermal stability of halloysite and magnesium silicateResults and Discussion : The magnesium silicate used in this study shows broad peaks in x-ray diffraction; however, the treatment of 750℃ induces its crystallization. The specific surface area of the magnesium silicate is also gradually decreased along with the firing temperature increase. No significant degradation in methylene blue adsorption capacity for magnesium silicate is observed until 500℃-treatment. However, the higher firing temperature reduces the capacity: 6.9%P, 27.3%P, and 91.2%P decrease for 600℃, 700℃, and 750℃, respectively. Regardless of heat treatment, the Langmuir isotherm equation represents the adsorption equilibria well compared to the Freundlich model. The tubular media of the halloysite – 30 wt% of magnesium silicate fired at 600℃ exhibits a high specific surface area of 115 m2 g-1 and a relative porosity of 43.5%. Compared to the halloysite-only tubular media, the adsorption capacity of the composites is significantly improved with the incorporation of magnesium silicate. The adsorption capacity of 168h for methylene blue is more than tripled, 29.8 mg g-1, and the adsorption capacity of Cr(III), Cu(II), and Zn(II) is also greatly enhanced by more than 4.8 times.Conclusion : The thermal stability of magnesium silicate is investigated for use as an additive adsorbent in terms of the microstructure and the adsorption capacity. Even at 600℃ of the firing temperature, magnesium silicate shows a higher specific surface area and higher adsorption capacity of MB compared to those of the halloysite; the adsorption fits well into Langmuir behavior. The addition of magnesium silicate into the halloysite media significantly enhances its adsorption capacity for MB and heavy metal ions such as Cr(III), Cu(II), and Zn(II).","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49492995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.525
N. Park, Suk-min Yoon, Sang-min Park, Hyeon-jeong Yun, Mi-ae Yun, Young-joo Lee
Objectives : The purpose of this study is to suggest operating conditions that can minimize the disinfection by-products of sodium hypochlorite produced in on-site sodium hypochlorite generators.Methods : The characteristics of disinfection by-products were investigated by operating conditions (dissolved water type, brine concentration, temperature of electrolytic cell inflow water, pH of electrolytic cell inflow water and electrolyzer current density) using a on-site sodium hypochlorite generator(5 kg/day).Results and Discussion : The concentration of disinfection by-products (chlorate, bromate) according to the type of dissolved water was found to be high in the order of softened water > tap water > RO treated water. As the brine concentration increased, chlorate decreased and bromate increased. The optimal saline concentration was found to be 3% or more. As temperature of electrolytic cell inflow water increases,, chlorate decreases and bromate increases. The difference in the concentration of disinfection by-products(chlorate, bromate) according to the pH of electrolytic cell inflow water is not large, and the appropriate pH is determined to be about 7 when the free available chlorine and disinfection by-products are taken into account. Also, as the current density increases, the chlorate increases and bromate showed a decreasing trend.Conclusion : It has been shown that the concentration of disinfection by-products can be minimized when operating within the operating range suggested by the on-site sodium hypochlorite generator manufacturer, and some operating conditions are thought to have been suggested by the manufacturer to protect the electrolyzer cells. As the market for on-site sodium hypochorite generator gradually expands, it is expected that improved facilities will be continuously released in consideration of the stricter standards for disinfection by-products.
{"title":"A Study on the Optimal Management Technology of the On-site Sodium Hypochlorite Generator for Disinfection By-products Reduction","authors":"N. Park, Suk-min Yoon, Sang-min Park, Hyeon-jeong Yun, Mi-ae Yun, Young-joo Lee","doi":"10.4491/ksee.2022.44.12.525","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.525","url":null,"abstract":"Objectives : The purpose of this study is to suggest operating conditions that can minimize the disinfection by-products of sodium hypochlorite produced in on-site sodium hypochlorite generators.Methods : The characteristics of disinfection by-products were investigated by operating conditions (dissolved water type, brine concentration, temperature of electrolytic cell inflow water, pH of electrolytic cell inflow water and electrolyzer current density) using a on-site sodium hypochlorite generator(5 kg/day).Results and Discussion : The concentration of disinfection by-products (chlorate, bromate) according to the type of dissolved water was found to be high in the order of softened water > tap water > RO treated water. As the brine concentration increased, chlorate decreased and bromate increased. The optimal saline concentration was found to be 3% or more. As temperature of electrolytic cell inflow water increases,, chlorate decreases and bromate increases. The difference in the concentration of disinfection by-products(chlorate, bromate) according to the pH of electrolytic cell inflow water is not large, and the appropriate pH is determined to be about 7 when the free available chlorine and disinfection by-products are taken into account. Also, as the current density increases, the chlorate increases and bromate showed a decreasing trend.Conclusion : It has been shown that the concentration of disinfection by-products can be minimized when operating within the operating range suggested by the on-site sodium hypochlorite generator manufacturer, and some operating conditions are thought to have been suggested by the manufacturer to protect the electrolyzer cells. As the market for on-site sodium hypochorite generator gradually expands, it is expected that improved facilities will be continuously released in consideration of the stricter standards for disinfection by-products.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49237428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.627
B. Kwon
Objectives:Plastic pollution is a very important environmental issue. The objective of this study is to monitor microplastics and styrene oligomers (SOs) as artificial chemical species that can be derived from polystyrene (PS) plastics. Methods:In order to achieve the above objective, this study collected atmospheric samples from the air of Gwangju City and Jeju Island and analyzed the concentrations of microplastics and SOs chemical species using Fourier transformed infrared spectroscopy (FTIR) and gas chromatography/mass spectroscopy (GC/MS). In this study, a stainless steel filter was used for the sampling of microplastics and SOs species.Results and Discussion:In 2019, the average concentration of SOs in the atmosphere of Gwangju City was 0.24 (± 0.56) µg/m3, and in 2020, the average concentration of SOs in Gwangju City was 0.10 (± 0.16)µg/m3. Those average concentration in Jeju Island in 2020 was monitored to be 0.11 (± 0.07) µg/m3. Moreover, the concentration of microplastics present in the atmosphere of Gwangju City and Jeju Island in 2020 ranged from 0.13 particles/m3 to 1.13 particles/m3. In this time, 9 types of microplastics were detected, and the most frequently detected microplastics were polyethylene (PE), polypropylene (PP), ethylene vinyl acetate (EVA), and acrylate materials. The monitored microplastic shapes were both fibers and fragments, suggesting that atmospheric microplastics are mainly released from fibers or caused by friction and breakage. Consequently, SOs and microplastics can be new pollution indicators for evaluating air quality. Conclusion:This study is the first attempt to monitor SOs compounds and microplastics, so it is expected to contribute to the evaluation of the extent of plastic pollution.
{"title":"Monitoring of Microplastics and Styrene Oligomers in the Atmosphere","authors":"B. Kwon","doi":"10.4491/ksee.2022.44.12.627","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.627","url":null,"abstract":"Objectives:Plastic pollution is a very important environmental issue. The objective of this study is to monitor microplastics and styrene oligomers (SOs) as artificial chemical species that can be derived from polystyrene (PS) plastics. Methods:In order to achieve the above objective, this study collected atmospheric samples from the air of Gwangju City and Jeju Island and analyzed the concentrations of microplastics and SOs chemical species using Fourier transformed infrared spectroscopy (FTIR) and gas chromatography/mass spectroscopy (GC/MS). In this study, a stainless steel filter was used for the sampling of microplastics and SOs species.Results and Discussion:In 2019, the average concentration of SOs in the atmosphere of Gwangju City was 0.24 (± 0.56) µg/m3, and in 2020, the average concentration of SOs in Gwangju City was 0.10 (± 0.16)µg/m3. Those average concentration in Jeju Island in 2020 was monitored to be 0.11 (± 0.07) µg/m3. Moreover, the concentration of microplastics present in the atmosphere of Gwangju City and Jeju Island in 2020 ranged from 0.13 particles/m3 to 1.13 particles/m3. In this time, 9 types of microplastics were detected, and the most frequently detected microplastics were polyethylene (PE), polypropylene (PP), ethylene vinyl acetate (EVA), and acrylate materials. The monitored microplastic shapes were both fibers and fragments, suggesting that atmospheric microplastics are mainly released from fibers or caused by friction and breakage. Consequently, SOs and microplastics can be new pollution indicators for evaluating air quality. Conclusion:This study is the first attempt to monitor SOs compounds and microplastics, so it is expected to contribute to the evaluation of the extent of plastic pollution.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43388682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.552
Daye Kang, Sung-Jun Lee, Jongkwan Park
Objectives:Since natural organic matter(NOM) is generated from an ecosystem, it has various characteristics depending on its origin. Especially, aquatic NOM reduces an efficiency of water treatment system and forms disinfection-by-products(DBPs) as a precursor. In this study, DBP formation potential was estimated according to the molecular structure of NOMs resulted by pyrolysis-gas chromatography-mass spectrometer(py-GC-MS). Methods:Five NOM samples were characterized: Suwannee River NOM(SRNOM), Mississippi River NOM(MRNOM), Nakdong River NOM(NR), NOM in effluent of Jinhae wastewater treatment plant(WP), and NOM in a small stream(SG) in Changwon city. The various analytical instruments were used including TOC analyzer, UV spectrometer, fluorescence spectrometer, and size-exclusion chromatography. After freeze drying of NOMs, molecular structure of samples was identified by py-GC-MS. Results and Discussion:Molecular weights of SRNOM and MRNOM were similar each other (~1400Da). The others(NR,WP,SG) were larger than the SRNOM and MRNOM. Hydrophobicity of the samples followed the order: SRNOM≒MRNOM > NR > WP > SG. Py-GC-MS results showed that SRNOM and MRNOM contain high portion of humic components. Otherwise, NR, WP, SG have protein which is originated from microbials. The DBP formation potential of SRNOM and MRNOM were the highest.Conclusion:This research shows the different characteristics of NOMs originated from different source. The results confirmed that NOM contained high portion of humic components results in the formation of high concentration of DBPs.
目的:天然有机物质(NOM)是由生态系统产生的，根据其来源的不同，它具有不同的特征。特别是，水生NOM降低了水处理系统的效率，并形成消毒副产物(DBPs)作为前体。本研究通过热解-气相色谱-质谱联用(py-GC-MS)测定NOMs的分子结构，估算DBP的形成势。方法:选取苏万尼河NOM(SRNOM)、密西西比河NOM(MRNOM)、洛东江NOM(NR)、镇海污水处理厂出水NOM(WP)和昌原市一小河(SG)中的5个NOM样品进行表征。采用TOC分析仪、紫外分光光度计、荧光分光光度计、排样色谱等多种分析仪器。NOMs冷冻干燥后，用py-GC-MS鉴定样品的分子结构。结果与讨论:SRNOM与MRNOM分子量相近(~1400Da)。NR、WP、SG均大于SRNOM和MRNOM。样品的疏水性依次为:SRNOM≒MRNOM > NR > WP > SG。Py-GC-MS结果表明，SRNOM和MRNOM含有较高比例的腐殖质成分。另外，NR、WP、SG中含有来源于微生物的蛋白质。SRNOM和MRNOM的DBP形成电位最高。结论:不同来源的NOMs具有不同的特性。结果证实，NOM中含有较高比例的腐殖质成分，从而形成高浓度的dbp。
{"title":"The estimation of DBPs formation potential depending on the molecular structure of natural organic matter","authors":"Daye Kang, Sung-Jun Lee, Jongkwan Park","doi":"10.4491/ksee.2022.44.12.552","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.552","url":null,"abstract":"Objectives:Since natural organic matter(NOM) is generated from an ecosystem, it has various characteristics depending on its origin. Especially, aquatic NOM reduces an efficiency of water treatment system and forms disinfection-by-products(DBPs) as a precursor. In this study, DBP formation potential was estimated according to the molecular structure of NOMs resulted by pyrolysis-gas chromatography-mass spectrometer(py-GC-MS). Methods:Five NOM samples were characterized: Suwannee River NOM(SRNOM), Mississippi River NOM(MRNOM), Nakdong River NOM(NR), NOM in effluent of Jinhae wastewater treatment plant(WP), and NOM in a small stream(SG) in Changwon city. The various analytical instruments were used including TOC analyzer, UV spectrometer, fluorescence spectrometer, and size-exclusion chromatography. After freeze drying of NOMs, molecular structure of samples was identified by py-GC-MS. Results and Discussion:Molecular weights of SRNOM and MRNOM were similar each other (~1400Da). The others(NR,WP,SG) were larger than the SRNOM and MRNOM. Hydrophobicity of the samples followed the order: SRNOM≒MRNOM > NR > WP > SG. Py-GC-MS results showed that SRNOM and MRNOM contain high portion of humic components. Otherwise, NR, WP, SG have protein which is originated from microbials. The DBP formation potential of SRNOM and MRNOM were the highest.Conclusion:This research shows the different characteristics of NOMs originated from different source. The results confirmed that NOM contained high portion of humic components results in the formation of high concentration of DBPs.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46562396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.560
Dong Sub Lee, Jin Su Park, Y. Sim
In order to reduce various environmental pollutants and green house gas emissions caused by the use of fossil fuels, countries around the world are making various efforts to revitalize the supply of eco-friendly vehicles such as FCEVs(fuel cell electric vehicles) and electric vehicles. As a policy to revitalize the supply of eco- friendly cars, it is pushing for purchase subsidies and tax reduction policies, and aims to supply 6.7 million fuel cell electric vehicles and 310 hydrogen charging stations by 2022. Meanwhile in order for eco-friendly cars to be activated, various policies such as subsidies, vehicle price reduction, easing various regulatory policies, and promoting incentive policies are needed, but above all, installing charging facilities is important to revitalize eco-friendly vehicles. In this study, the current status of the FCEV industry and the promotion strategy according to the supply of FCEVs were presented to revitalize the supply of the FCEVs suitable for the situation in Gyeongsangbuk-do. The first, practical hydrogen utilization measures should be prepared first in purchasing business vehicles through a plan to supply FCEVs, expand subsides to revitalize the supply of FCEVs, and secure subsidies for operation of hydrogen charging stations. The second, it is necessary to build a hydrogen production base in Gyeongsangbuk-do to expand the FCEV infrastructure, build an institutional plan to revitalize FCEVs, and reduce hydrogen costs through green hydrogen production and production base construction. The third, it is necessary to train professionals, in the hydrogen industry and promote the transformation of local people’s perception of hydrogen and hydrogen charging stations. Therefore, Gyeongsangbuk-do can secure competitiveness in the hydrogen industry by supplying FCEVs and expanding hydrogen charging stations, and contribute for forstering the hydrogen economy, a key driving force for future innovation growth and energy conversion.
{"title":"A Study on the Construction of Fuel Cell Electric Vehicle and Hydrogen Charging Station Supply Activation(mainly in Gyeongsangbuk-do)","authors":"Dong Sub Lee, Jin Su Park, Y. Sim","doi":"10.4491/ksee.2022.44.12.560","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.560","url":null,"abstract":"In order to reduce various environmental pollutants and green house gas emissions caused by the use of fossil fuels, countries around the world are making various efforts to revitalize the supply of eco-friendly vehicles such as FCEVs(fuel cell electric vehicles) and electric vehicles. As a policy to revitalize the supply of eco- friendly cars, it is pushing for purchase subsidies and tax reduction policies, and aims to supply 6.7 million fuel cell electric vehicles and 310 hydrogen charging stations by 2022. Meanwhile in order for eco-friendly cars to be activated, various policies such as subsidies, vehicle price reduction, easing various regulatory policies, and promoting incentive policies are needed, but above all, installing charging facilities is important to revitalize eco-friendly vehicles. In this study, the current status of the FCEV industry and the promotion strategy according to the supply of FCEVs were presented to revitalize the supply of the FCEVs suitable for the situation in Gyeongsangbuk-do. The first, practical hydrogen utilization measures should be prepared first in purchasing business vehicles through a plan to supply FCEVs, expand subsides to revitalize the supply of FCEVs, and secure subsidies for operation of hydrogen charging stations. The second, it is necessary to build a hydrogen production base in Gyeongsangbuk-do to expand the FCEV infrastructure, build an institutional plan to revitalize FCEVs, and reduce hydrogen costs through green hydrogen production and production base construction. The third, it is necessary to train professionals, in the hydrogen industry and promote the transformation of local people’s perception of hydrogen and hydrogen charging stations. Therefore, Gyeongsangbuk-do can secure competitiveness in the hydrogen industry by supplying FCEVs and expanding hydrogen charging stations, and contribute for forstering the hydrogen economy, a key driving force for future innovation growth and energy conversion.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"70473827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.589
Dong Hwi Lee, Eue-tae Kang, J. Joo, Hyeon Woo Go, C. Ahn, Yong Hyeon Bae, Kwang-Duck Song
Objectives:A large-scale freshwater lake is a freshwater lake with a storage of 5,000,000 tons or more among freshwater lakes. It is located at the end of the basin, so complex and various pollutants flow in from a wide basin, and it has a characteristic of longer retention and greater accumulation for a long time in the lake. Since the continuous inflow and accumulation of non-point pollution sources for agricultural purpose occurred due to the repeated reuse of agricultural water near freshwater lakes, and the complex water use and occurred drainage structure, water pollution is aggravating. In this study, the main pollution sources of large-scale freshwater lakes were derived through multivariate statistical analysis using various water quality factors for efficient freshwater lake management. The analysis is performed out to predict the future Chlorophyll-a(Chl-a) and to identify major factors affecting algal growth, and to use them as establish effective countermeasures to improve water quality based on the characteristics of freshwater lakes algal growth the future.Methods:In the case of GanWol(GW), GeumGang(GG), GeumHO(GeH), NamYang(NY), DaeHo(DH), BuNam(BN), SapGyo(SG), ASan(AS), YoungSan(YS), YoungAm(YA) in the water environment information system operated by the Ministry of Environment, water quality data on a monthly basis for 10 years from January, 2011 to December, 2020 were collected from three point measurement located in the lake. In the case of GoHeung(GoH), GunNae(GN), Busa(BS), SeokMoon(SM), and HaeNam(HN), water quality data were collected on a quarterly basis for 5 years from April 2015 to March 2019 from one point measurement located in the lake.Results and Discussion:As a result of Korean trophic state index (TSIko) analysis, most of the large-scale freshwater lakes in the central region of the West Sea were classified as Hypertrophic, and all of the large-scale freshwater lakes in the southern region of the West Sea were classified as Eutrophic. Based on the results from factor analysis and principal component analysis, countermeasures against organic matters, nutrients, and algal bloom in terms of type of large-scale freshwater lake should be prepared. As a result of multiple linear regression analysis for Chl-a prediction, large-scale freshwater lakes in the central region of the West Sea had higher explanatory rates than large-scale freshwater lakes in the southern region of the West Sea, but all were analyzed below 0.8, suggesting that the accuracy was not high.Conclusions:BOD, COD, TOC, T-N, and T-P concentration of freshwater lakes in the central region of the West Sea have more deterioating water quality than freshwater lakes in the southern region of the West Sea, suggesting that organic pollutants and nutrients need to be managed. As a result of the factor analysis, it is judged that organic matter & algae type nutrient type, and complex type classification, and appropriate water quality management measures for ea
{"title":"Water Quality Analysis and Chl-a Prediction of 15 Large-scale Freshwater Lakes in Korea by Multivariate Statistical Analysis","authors":"Dong Hwi Lee, Eue-tae Kang, J. Joo, Hyeon Woo Go, C. Ahn, Yong Hyeon Bae, Kwang-Duck Song","doi":"10.4491/ksee.2022.44.12.589","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.589","url":null,"abstract":"Objectives:A large-scale freshwater lake is a freshwater lake with a storage of 5,000,000 tons or more among freshwater lakes. It is located at the end of the basin, so complex and various pollutants flow in from a wide basin, and it has a characteristic of longer retention and greater accumulation for a long time in the lake. Since the continuous inflow and accumulation of non-point pollution sources for agricultural purpose occurred due to the repeated reuse of agricultural water near freshwater lakes, and the complex water use and occurred drainage structure, water pollution is aggravating. In this study, the main pollution sources of large-scale freshwater lakes were derived through multivariate statistical analysis using various water quality factors for efficient freshwater lake management. The analysis is performed out to predict the future Chlorophyll-a(Chl-a) and to identify major factors affecting algal growth, and to use them as establish effective countermeasures to improve water quality based on the characteristics of freshwater lakes algal growth the future.Methods:In the case of GanWol(GW), GeumGang(GG), GeumHO(GeH), NamYang(NY), DaeHo(DH), BuNam(BN), SapGyo(SG), ASan(AS), YoungSan(YS), YoungAm(YA) in the water environment information system operated by the Ministry of Environment, water quality data on a monthly basis for 10 years from January, 2011 to December, 2020 were collected from three point measurement located in the lake. In the case of GoHeung(GoH), GunNae(GN), Busa(BS), SeokMoon(SM), and HaeNam(HN), water quality data were collected on a quarterly basis for 5 years from April 2015 to March 2019 from one point measurement located in the lake.Results and Discussion:As a result of Korean trophic state index (TSIko) analysis, most of the large-scale freshwater lakes in the central region of the West Sea were classified as Hypertrophic, and all of the large-scale freshwater lakes in the southern region of the West Sea were classified as Eutrophic. Based on the results from factor analysis and principal component analysis, countermeasures against organic matters, nutrients, and algal bloom in terms of type of large-scale freshwater lake should be prepared. As a result of multiple linear regression analysis for Chl-a prediction, large-scale freshwater lakes in the central region of the West Sea had higher explanatory rates than large-scale freshwater lakes in the southern region of the West Sea, but all were analyzed below 0.8, suggesting that the accuracy was not high.Conclusions:BOD, COD, TOC, T-N, and T-P concentration of freshwater lakes in the central region of the West Sea have more deterioating water quality than freshwater lakes in the southern region of the West Sea, suggesting that organic pollutants and nutrients need to be managed. As a result of the factor analysis, it is judged that organic matter & algae type nutrient type, and complex type classification, and appropriate water quality management measures for ea","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43003079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.616
Y. Yoon, S. Yun
As the increase of carbon dioxide in atmospheric accelerates climate change, various efforts have been performed to reduce carbon worldwide. Recently, as the concept of green carbon stored and sequestrated through photosynthesis by land plants has been emphasized to reduce carbon content from environments, the importance of carbon absorption survey for plant groups analysis of terrestrial ecosystems such as forests and river wetlands is increasing. Carbon absorption sources in terrestrial ecosystems exist in various forms of plant, soil, and topography, and represent various carbon absorption through physical, chemical and biological reactions between each other depending on the location and height of the plant groups. In this study, an industrial RTK drone capable of taking high-resolution images was used for efficient carbon absorption survey in Damyang stream wetland. Based on the global navigation satellite system by RTK, the location could be corrected in real time, and ecosystem surveys could be conducted on the height of the terrain with RTK drone. The point cloud technique of the high-density surface model was used to analyze the three-dimensional topography of areas that are difficult to access. Using the photo survey function of the RTK drone, it is expected to play an important role in understanding the total amount of green carbon of terrestrial ecosystems and carbon circulation of the land ecosystem by enabling the creation of topographic maps of stream wetlands, and riparian vegetation with complex terrain.
{"title":"Methodology for Topographic Survey of Carbon Absorption Sources in Stream Wetland Using Industrial Drone","authors":"Y. Yoon, S. Yun","doi":"10.4491/ksee.2022.44.12.616","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.616","url":null,"abstract":"As the increase of carbon dioxide in atmospheric accelerates climate change, various efforts have been performed to reduce carbon worldwide. Recently, as the concept of green carbon stored and sequestrated through photosynthesis by land plants has been emphasized to reduce carbon content from environments, the importance of carbon absorption survey for plant groups analysis of terrestrial ecosystems such as forests and river wetlands is increasing. Carbon absorption sources in terrestrial ecosystems exist in various forms of plant, soil, and topography, and represent various carbon absorption through physical, chemical and biological reactions between each other depending on the location and height of the plant groups. In this study, an industrial RTK drone capable of taking high-resolution images was used for efficient carbon absorption survey in Damyang stream wetland. Based on the global navigation satellite system by RTK, the location could be corrected in real time, and ecosystem surveys could be conducted on the height of the terrain with RTK drone. The point cloud technique of the high-density surface model was used to analyze the three-dimensional topography of areas that are difficult to access. Using the photo survey function of the RTK drone, it is expected to play an important role in understanding the total amount of green carbon of terrestrial ecosystems and carbon circulation of the land ecosystem by enabling the creation of topographic maps of stream wetlands, and riparian vegetation with complex terrain.","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45537680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-12-31DOI: 10.4491/ksee.2022.44.12.603
Hyeon Woo Go, Soo-Young Moon, H. Kim, So Ye Jang, E. Kang, J. Joo
Objectives:In order to recycle and resource waste glass, the feasibility of foam glass as filter media was evaluated, and column experiments using foam glass media were conducted to confirm the applicability as filter media in rain garden. Through this experiment, various design factors to be considered can be derived in application of foam glass media in the rain garden.Methods:Sieve analysis and SEM/EDS analysis were conducted to confirm the physicochemical properties of the foam glass. Column experiments filled with only foam glass and mixtures of sand and foam glass were conducted to simulate rain garden to evaluate the removal efficiency of suspended solids and turbidity using the foam glass media, head difference (Δh) and hydraulic conductivity (K) changes, and calculation of filtered suspended solids loading using both discrete and cumulative mass approach. Finally, comparison of filtration performance with various filter media used in LID facilities was performed to evaluate the feasibility of foam glass media in rain garden.Results and Discussion:Since foam glass media has a lower density than water, homogeneous particle size, and smooth surface with pores of various sizes, foam glass media effectively induces internal capture and external adsorption of suspended solids. Foam glass media has been applied to high suspended solids and turbidity removal efficiency. As the suspended solids inflow load increased, clogging occurred in the pores and the removal efficiency gradually decreased, but the foam glass media with lower density than water was continuously disturbed and rearranged due to the head difference energy, and some clogging were alleviated by rearrangement of pores and channels. The load of suspended solids in precipitated, adsorbed, and retained on the foam glass was calculated using the effluent sample (discrete) collected at regular time intervals and the continuously accumulated sample (cumulative) from the output. The filtered suspended solids load calculated using the cumulative mass approach was higher due to the estimation of the amounts of suspended solids remaining in the filtration column is lower because the samples (discrete) collected at regular time intervals from the output do not reflect the amount of suspended solids that change over time. Thus, the amounts of suspended solids removed through the filtration process can be much more accurately estimated using the cumulative samples. Finally, when comparing the removal efficiency with other filter media, foam glass can be used as excellent filter media with higher removal efficiency and greater lifespan.Conclusion:Foam glass media with smooth surface, pores of various sizes, and lower density than water can rearrange and regenerate pores to alleviate some clogging, resulting in high suspended solids and turbidity removal efficiency for a long period of time. Considering that the amount of suspended solids filtered is determined by various factors such as particle
{"title":"Evaluation of the Feasibility of Foam Glass as Filter Media in Rain Garden","authors":"Hyeon Woo Go, Soo-Young Moon, H. Kim, So Ye Jang, E. Kang, J. Joo","doi":"10.4491/ksee.2022.44.12.603","DOIUrl":"https://doi.org/10.4491/ksee.2022.44.12.603","url":null,"abstract":"Objectives:In order to recycle and resource waste glass, the feasibility of foam glass as filter media was evaluated, and column experiments using foam glass media were conducted to confirm the applicability as filter media in rain garden. Through this experiment, various design factors to be considered can be derived in application of foam glass media in the rain garden.Methods:Sieve analysis and SEM/EDS analysis were conducted to confirm the physicochemical properties of the foam glass. Column experiments filled with only foam glass and mixtures of sand and foam glass were conducted to simulate rain garden to evaluate the removal efficiency of suspended solids and turbidity using the foam glass media, head difference (Δh) and hydraulic conductivity (K) changes, and calculation of filtered suspended solids loading using both discrete and cumulative mass approach. Finally, comparison of filtration performance with various filter media used in LID facilities was performed to evaluate the feasibility of foam glass media in rain garden.Results and Discussion:Since foam glass media has a lower density than water, homogeneous particle size, and smooth surface with pores of various sizes, foam glass media effectively induces internal capture and external adsorption of suspended solids. Foam glass media has been applied to high suspended solids and turbidity removal efficiency. As the suspended solids inflow load increased, clogging occurred in the pores and the removal efficiency gradually decreased, but the foam glass media with lower density than water was continuously disturbed and rearranged due to the head difference energy, and some clogging were alleviated by rearrangement of pores and channels. The load of suspended solids in precipitated, adsorbed, and retained on the foam glass was calculated using the effluent sample (discrete) collected at regular time intervals and the continuously accumulated sample (cumulative) from the output. The filtered suspended solids load calculated using the cumulative mass approach was higher due to the estimation of the amounts of suspended solids remaining in the filtration column is lower because the samples (discrete) collected at regular time intervals from the output do not reflect the amount of suspended solids that change over time. Thus, the amounts of suspended solids removed through the filtration process can be much more accurately estimated using the cumulative samples. Finally, when comparing the removal efficiency with other filter media, foam glass can be used as excellent filter media with higher removal efficiency and greater lifespan.Conclusion:Foam glass media with smooth surface, pores of various sizes, and lower density than water can rearrange and regenerate pores to alleviate some clogging, resulting in high suspended solids and turbidity removal efficiency for a long period of time. Considering that the amount of suspended solids filtered is determined by various factors such as particle","PeriodicalId":52756,"journal":{"name":"daehanhwangyeonggonghaghoeji","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41939252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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