• Journal of Korean Society on Water Environment
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• v.21 no.6
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• pp.664-668
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• 2005

An experimental study for the comparison of nitrogen and phosphorus removal efficiencies between $A^2/O$ and modified Phostrip (M-Phostrip process) were carried out with bench-scale reactors. In case of nitrogen removal efficiencies both of processes showed similar ones when influent organic loadings were high. However, M-phostrip process was more effective than $A^2/O$ at low organic loadings. This is why M-phostrip process consumes the whole mass of influent organics as a carbon sources for denitrification in anoxic reactor but the anoxic reactor of $A^2/O$ process utilizes the residual carbon followed by consumming a part of influent carbon for phosphorus release in anaerobic reactor. $A^2/O$ process required the influent COD/T-P and COD/TKN ratios were more than 56 and 10, respectively, to take place the phosphorus release in anaerobic process and phosphorus uptake in oxic process. However, the luxury uptake of phosphorus in M-phostrip process was not affected by influent COD/T-P and COD/TKN ratios and the adverse effect of nitrate in return sludge introduced to the p-stripper from the 2nd clarifier was not significant due to the configurational advantage of the p-stripper.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.711-718
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• 2014

Investigated the processing characteristics of the pollutants and runoff due to storm events in the actual application of the road fields and a Non-Point Sources (NPS) pilot scale equipment. This phenomenon has occurred in the influent bypass the blockage occurs after 90 min the expended polymeric media was filled with filtered column. When entering a treatment tank SS 200 mg/L or more high concentration of effluent treatment efficiency was reduced from the reaction time 60 min. Influent concentration less then SS 180 mg/L was stable handling. The $COD_{Cr}/SS$ ratio were analyzed with 0.67, median value. Showed 92.1% and 82.3% respectively with an average removal rate of the SS and the $COD_{Cr}$. If the influent concentration of TP is the 0.5 mg/L or less, the quality of the treated water is 0.1 mg/L levels were expressed in a stable process. And when entering the 1.0 mg/L or more of the treated water, had a greater than average 0.2 mg/L. If the influent concentration of TN is 4~10 mg/L, the treatment water quality level was kept a 1.5~3.0 mg/L. The average removal efficiency of TP and TN respectively 73.9%, 50.4%.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.5
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• pp.141-153
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• 2004

Wetland system is widely accepted as one of natural water purification systems around the world for nonpoint sources pollution control. Constructed wetlands have become a popular technology for treating contaminated surface and waste water. In this study, the field experiment to reduce nonpoint source pollution loadings from polluted stream waters using wetland system was performed from June 2002 to March 2004. Four wetlands were used and the size of each one was 0.8ha. Water of Dangjin stream flowing into Seokmun estuarine reservoir was pumped into wetlands. Inflow and hydraulic residence time of the system was 500 $m^3$/day∼1,500 $m^3$/day, 2∼5 days, respectively. After 2 year operation, plant-coverage of the wetlauds was about 70% from bare soil surface at initial stage . Average water quality of the influent was $BOD_5$ 4.17 mg/L, TSS 18.45 mg/L, T-N 4.32 mg/L, and T-P 0.30 mg/L. The average removal rate of $BOD_5$, TSS, T-N and T-P during the study period was 5.6%, 46.6%, 45.7%, and 54.8%, respectively. Organic ($BOD_5$) removal rate was low and the reason might be low influent concentration. Wetland removal rate of T-P was about 10% higher than T-N. Performance of the experimental system was compared with existing data base (NADB), and it was within the range of general system performance. Overall, the wetland system was found to be adequate for treating polluted water stream with stable removal efficiency even during the winter period. Most of the nonpoint source pollutions from watershed are transported by streams or ditches, and they could be controled by constructed wetland system before entering the lake or reservoir.

• 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.

• Journal of the Korean Society of Marine Environment & Safety
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• v.26 no.2
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• pp.206-218
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• 2020

Located mostly inside the megacity of Busan, the Busan Southern Port is a multifunctional port with various nearby industry activities, including a joint fish market, ship repair facilities, and fishing boat facilities. If toxic chemicals generated by the industrial activities continue to flow into and accumulate in the sediment of the port, they can affect aquatic ecosystems and humans. Therefore, in this study, distribution levels and potential influent sources of organic pollutants, including polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and butyltin compounds (BTs), in the sediment were investigated. The sediment samples were collected from eight sampling sites in November 2013 (first phase) and November 2014 (second phase). The mean concentrations of PAHs, PCBs, and BTs in the first and second sampling phages were 4174.0 ng/g-dry wt. and 1919.0 ng/g-dry wt., 166.3 ng/g-dry wt. and 21 ng/g-dry wt., and 50.9 ng/g-dry wt. and 30.8 ng/g-dry wt., respectively. The concentrations of the organic pollutants detected in the seabed sediments were lower in the second phase than in the first phase. In this study, the inflow sources of PAHs, PCBs, and BTs were found to be combustion, land, and municipal sewage or industrial wastewater, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.6
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• pp.735-741
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• 2009

This study intends to evaluate the efficiency of non-point source reduction technique by using the porous lightweight and recycled aggregate which microorganism is seeded. In case of infiltration velocity 30~70 mm/hr in high concentration of influent, it is indicated that SS was 40~94%, COD 44~91%, BOD 4~91%, TN 1.2~66%, TP 7~70% of removal efficiency. Removal efficiency is good in infiltration velocity 30 > 50 > 70㎜/hr order. Therefore, the non-point source treatment facility filled with lightweight and recycled aggregate using microbial seeding shows higher removal efficiency than a conventional sand and gravel. We confirm that the function and efficiency are improved significantly and applied to treat non-point sources.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2002.04a
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• pp.254-257
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• 2002

The purposes of this research are to identify the source and to analyze the pathway of nitrate contamination in "cultural village", Jeungpyeong. In order to examine recharge processes and flow pattern that closely related to the influent of nitrate contaminant, the flow field was simulated and the oxygen and hydrogen stable isotopes were analyzed. The nitrogen isotope was used to delineate contaminant sources. The shallow groundwater was mainly composed of precipitation, but leakage of domestic water and sewage contributed to the recharge. Nitrate contaminants were possibly from the leakage of sewage and animal waste. The nitrate concentration decreased due to dilution by low concentration water.ion water.

• Journal of Korean Society on Water Environment
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• v.23 no.1
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• pp.122-130
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• 2007

This study was conducted to evaluate water treatment characteristics according to vegetated wetland(V) and open water(O) arrangements in free water surface constructed wetland. Three pilot-scale wetlands, V-V, O-V and V-O, were built and operated. $BOD_5$ was a slightly reduced at all the arrangements because the influent concentration was so low as background concentration of constructed wetlands. While T-N and T-P removal efficiency showed higher than 50% for all cases. The O-V arrangement showed the highest removal efficiency: 20% for $BOD_5$, 56% for SS, 59% for T-N and 72% for T-P. Effluent concentration of the O-V were significantly low compared with those from the V-O. O-V arrangement would be beneficial in the light of pollutant removal efficiency as well as construction cost.

• Ocean and Polar Research
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• v.45 no.3
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• pp.103-111
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• 2023

To evaluate the impact of effluents from land-based fish farms on the coastal ocean of Wando, Korea, we analyzed inorganic nutrients, particulate organic carbon (POC), dissolved organic carbon (DOC), and colored dissolved organic matter (CDOM) in the effluent and influent of land-based fish farms during the summer (July) of 2021. The average concentrations of nutrients (Dissolved inorganic nitrogen, phosphorus, and silicate; DIN, DIP, and DSi, respectively) in the effluents of this study area were 17±3.7 μM, 1.4±0.7 μM, and 14±1.6 μM, respectively. The average concentrations of POC and DOC were 37±22 μM and 81±13 μM, respectively, with POC accounting for about 30% for total organic carbon in effluents. The Reduced Dissolved Inorganic Nitrogen/Total Dissolved Inorganic Nitrogen ratio (0.7), potential short-period index, indicates that the discharge of nutrients excreted by the fish and unconsumed feed into coastal water results in such nutrients being deposited and accumulated in the sediment. Subsequently, this continuous accumulation triggers the release of ammonium ions during organic matter decomposition, and the ammonium-enriched waters that encroach on fish farms as influent seem to be due to the diffusion of high concentrations of ammonium from bottom sediment. Furthermore, we used fluorescence indices to examine the characteristics of organic matter sources, obtaining mean values of 1.54±0.19, 1.06±0.06, and 1.56±0.06 for the humification index, biological index, and fluorescence index, respectively, in the effluent. These results indicate that the organic matters had an autochthonous origin that resulted from microbial decomposition, and such organic matters were rapidly generated and removed by biological activity, likely supplied from the sediment. Our results suggest that the effluent from land-based fish farms could be a potential source of deoxygenation occurrence in coastal areas.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.6
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• pp.332-339
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• 2015

Nitrogen removal is one of the most important issues about wastewater treatment because nitrogen is a primary pollutant caused various problems such as eutrophication. We developed a CANON microbial community by using AOB and ANAMMOX bacteria as seeding sources. When 100 mg-N/L of influent ammonium was supplied, the DO above 0.4 mg/L showed a very low TN removal efficiency while the DO of 0.3 mg/L showed TN removal efficiency as high as 71.3%. When the influent ammonium concentration was reduced to 50 mg/L, TN removal efficiency drastically deceased. However, TN removal efficiency was recovered to above 70% after 14 day operation when the influent nitrogen concentration was changed again from 50 mg-N/L to 100 mg-N/L. According to the operating temperature from $37{\pm}1^{\circ}C$ to $20{\pm}1^{\circ}C$, TN removal efficiency also rapidly decreased but gradually increased again up to $70.0{\pm}2.6$%. The analysis of PCR-DGGE showed no substantial difference in microbial community structures under different operational conditions. This suggests that if CANON sludge is once successfully developed from a mixture of AOB and ANAMMOX bacteria, the microbial community can be stably maintained regardless of the changes in operational conditions.