• Journal of Korean Society of Water and Wastewater
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• v.18 no.6
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• pp.807-813
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• 2004

Wastewater was treated by two different treatment processes; activated sludge process and advanced wastewater treatment process (KNR process) using lab-scale experiment. Two treated wastewater showed good treatment efficiency of organic matter removal, up to 90% removal. Nitrogen and phosphorus were not effectively removed though activated sludge process, while KNR process showed good removal efficiency of nitrogen and phosphorus; 56% nitrogen removal and 95% phosphorus removal. KNR process showed better removal efficiency of organic matter, nitrogen, and phosphorus compared to activated sludge process. Organic matter characterization was tracked though measurement of UV scan, SUVA, and XAD fractionation. Treated wastewater showed higher SUVA value than wastewater influent, indicting less aromatic characteristic of organic matter. XAD fractionation showed hydrophilic fraction decreased though wastewater treatment, suggesting microbes preferentially digest hydrophilic and aliphatic molecules rather than hydrophobic and aromatic molecules of organic matter.

• Journal of Environmental Science International
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• v.32 no.6
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• pp.465-475
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• 2023

In this study, we evaluated the treatment efficiency of livestock wastewater by altering the current density using boron-doped diamond (BDD) electrodes. As the current density was adjusted from 10 to 35 mA/cm2, the removal efficiency of organic matter increased from 22.2 to 71.5%. Similar to that of organic matter, the removal efficiency of color increased with increasing current density up to 85.7%, indicating a higher removal efficiency for color than that of organic matter. The removal efficiency of ammonia nitrogen increased from 14.6 to 53.3% as the current density increased, but it was lower than that of organic matter. In addition, the removal of organic matter, color, and ammonia nitrogen followed first-order reactions, according to the reaction rate analysis. The energy consumption ranged from 4.87 to 8.33 kWh/kg COD, and it was found that the organic matter removal efficiency was more efficient at high current densities. Based on various analyses, the optimal current density was 20 mA/cm2, and the corresponding energy consumption was 6.824 kWh/kg COD.

• Journal of Korean Society on Water Environment
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• v.39 no.6
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• pp.465-474
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• 2023

The chemical composition and molecular weight characteristics of dissolved organic matter (DOM) exert a profound influence on the efficiency of organic matter removal in water treatment systems, acting as efficiency predictive indicators. This research evaluated the primary chemical and molecular weight properties of DOM derived from diverse sources, including rivers, lakes, and biomasses, and assessed their relationship with the efficiency of coagulation/flocculation treatments. Dissolved organic carbon (DOC) removal efficiency through coagulation/flocculation exhibited significant correlations with DOM's hydrophobic distribution, the ratio of humic-like to protein-like fluorescence, and the molecular weight associated with humic substances (HS). These findings suggest that the DOC removal rate in coagulation/flocculation processes is enhanced by a higher presence of HS in DOM, an increased influence of externally sourced DOM, and more presence of high molecular weight compounds. The results of this study further posit that the efficacy of water treatment processes can be more accurately predicted when considering multiple DOM characteristics rather than relying on a singular trait. Based on major results from this study, a predictive model for DOC removal efficiency by coagulation/flocculation was formulated as: 24.3 - 7.83 × (fluorescence index) + 0.089 × (hydrophilic distribution) + 0.102 × (HS molecular weight). This proposed model, coupled with supplementary monitoring of influent organic matter, has the potential to enhance the design and predictive accuracy for coagulation/flocculation treatments targeting DOC removal in future applications.

• Transactions of the Korean hydrogen and new energy society
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• v.31 no.6
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• pp.546-552
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• 2020

In this study, optimization research was conducted through statistical analysis with the aim of maximizing the efficiency of organic matter reduction and hydrogen production by applying electrolysis process at sewage treatment plant. Statistical analysis and optimal operating conditions of organic matter removal efficiency and H2 generation, which varied with various conditions in the electrolysis process, were derived using response surface methodology. As a result, 1,268 μS/cm of conductivity, 350 A current, and pH 3.2 was found to be the optimum condition to reach the desired value as 38% of organic matter reduction and 2.58 L/min of H2 production. The experiment also determined that the optimization study was reliable. Base on this study, it was confirmed that the removal of organic matter and hydrogen production could be stably by applying the electrolysis process in the sewage treatment plant.

• Journal of Environmental Science International
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• v.32 no.7
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• pp.483-492
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• 2023

In this study, the treatment of livestock wastewater using an aerobic granular sludge based sequencing batch reactor was investigated. The reactor operation was carried out by general injection and split injection methods. The average removal efficiency of organic matter after the adaptation period was 71.5 and 87.4%, respectively. Some untreated organic matter was attributed to recalcitrant organic matter. The average removal efficiency of total nitrogen was 65.6 and 88.4%, respectively. These results indicate that the denitrification reaction by split injection was carried out smoothly. As for the solids, the ratio of aerobic granular sludge/mixed liquor suspended solid can be determined as the main factor of the process operation, and the ratio increased gradually and finally reached 86.0%. Correspondingly, the sludge volume index (SVI) was also improved, reaching 54 mL/g at the end of operation, and it is believed that the application of a short settling time contributed to the improvement of settleability.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.401-410
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• 2017

This study analyzed the changes in the concentrations of organic matters in constructed treatment wetlands, coming from discharge water from a sewage treatment plant and non-point pollutant sources during rainfall events. At the beginning of a rainfall event, a massive amount of particulate organic matter flowed in, and was removed from the sedimentation basin (S1, S2); dissolved organic matter was removed after passing through stepwise treatment processes in the wetland. During dry period in the wetland, the removal efficiency rate for COD and TOC was -21 and -7%, respectively; during the rainfall event, the removal efficiency rate for COD and TOC were 47 and 43%, respectively. The highly-concentrated organic matters that flowd in at the beginning of the rainfall event was stabilized by various structures in the wetland before water discharge. Cyanobacteria blooms annually at the confluence of the So-ok stream and Daecheong Lake. Therefore, it is expected that the wetland will contribute significantly to reducing cyanobacteria and improving water quality in the area.

• Membrane and Water Treatment
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• v.7 no.1
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• pp.1-10
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• 2016

Ultrafiltration is known to be one of the most commonly applied techniques in water treatment. Membrane fouling is the main limiting factor in terms of process efficiency and restricting it to the manageable degree is crucial. Natural organic matter is often found to be a major foulant in surface waters. Among many known fouling prevention techniques, the membrane chemical cleaning is widely employed. This study focuses on evaluating the cleaning efficiency of polymeric and ceramic membranes with the use of various chemicals. The influence of cleaning agent type and its concentration, membrane material and its MWCO, and cleaning process duration on the recovery of membrane flux was analyzed. Results have shown that, regardless of membrane type and MWCO, the most effective cleaning agent was NaOH.

• Journal of Korean Society on Water Environment
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• v.20 no.6
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• pp.708-713
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• 2004

This study was performed to investigate the variations of hydrophilic and hydrophobic organic matter fractions in soluble organic matter according to livestock wastewater treatment by ionized gas and coagulation effect to these fractions after ionized gas contact. As a result of experiment, because of ionized gas contact, particle in the surface of livestock wastewater was more smaller and the result was consisted of particle size analysis and the amount of small size was increased. Also, we confirmed that organic matters in livestock wastewater by ionized gas contact were removed. The relation equation between ionized gas contact time(X) and $TCOD_{cr}$(Y) was shown as yscale(y)=3.748-0.431* xscale(X). That between ionized gas contact time(X) and $TCOD_{cr}$(Y) was yscale(y)=3.283-0.463* xscale(X). As respects the HPL(hydrophilic matter)and HPO(hydrophobic matter) fractions of raw in livestock wastewater treatment plant, HPL fraction was 53.2% and HPO fraction was 46.8%. But, HPO fraction according to ionized gas treatment was increased at 30min and after that time, HPL fraction was increased. Also, when we performed coagulation process after ionized gas treatment of raw wastewater, the removal efficiency of organic matter was the highest at 30min of ionized gas treatment because of the variation of HPL and HPO fractions in organic matter by ionized gas. In coagulation process following after ionized gas process, HPO was removed more effective than HPL.

• Journal of Wetlands Research
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• v.16 no.4
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• pp.423-431
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• 2014

Supply of rural community sewage treatment plant (RCSTP) is need for protect of water quality like water source and development of agriculture areas. In this study conducted analysis on characteristics of RCSTP sewage and treatment efficiency of installed treatment process using operation results of RCSTP in an-dong area. high organic matter and nutrient were contained in RCSTP sewage of an-dong than urban area. RCSTP treatment process in an-dong was shown stable treatment efficiency. But nutrient treatment efficiency was shown more sensitive result about SRT and F/M ratio than organic matter treatment efficiency. And RCSTP treatment process in an-dong was shown higher treatment efficiency than other treatment proces like $A^2/O$, SBR and media. Thus, this process is effective treatment process for application of RCSTP.

• Journal of Korean Society on Water Environment
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• v.33 no.5
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• pp.580-586
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• 2017

The fractionation characteristics of organic matter were investigated in inflow and effluent of each other pollution sources and river. While the DOC/TOC ratio in the influent of public sewage treatment plant and livestock disposal facilities was above 0.58, the POC/TOC ratio of human livestock Night soil treatment plant and stormwater runoff was more than 0.7. The TOC removal efficiency of public sewage treatment plant and human livestock Night soil treatment plant were 88.5 % and 99.6 %, respectively. Although the concentration distribution of organic matter pollution most of total organic carbon (TOC) in effluent of pollution sources accounted for dissolved organic carbon (DOC) type (DOC/TOC ratio >0.89) and Refractory-DOC (RDOC)/TOC ratio was higher (>0.65). The fractionation characteristics of organic matter in river were similar with that of sewage treatment plant and TOC concentration showed the positive correlation with DOC ($r^2=0.93$) and RDOC ($r^2=0.89$) concentration. The decay rate of Labile DOC (LDOC) (avg. $0.128day^{-1}$) was higher than labile particulate organic carbon (LPOC) ($0.082day^{-1}$), while that of DOC ($0.008day^{-1}$) was lower than POC ($0.039day^{-1}$) (paired t-test, p < 0.001, n = 5). These study results suggested that it should consider important both TOC and DOC as the target indicator to control refractory organic matter in pollution sources.