• Journal of Environmental Health Sciences
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• v.34 no.5
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• pp.374-381
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• 2008

In this study, the factors affecting biological N and P removal using SND (simultaneous nitrification and denitrification) process were investigated and evaluated to examine the possibility of treating N and P through SND with NADH by surveying N and P traces in an aeration tank. Variations of $NH_4^+$-N+$NO_3^-$-N concentration were used to estimate the degree of SND in each point (P2, P3, P4, P5) of the aeration tank and these variations showed that denitrification efficiency in P2 (front zone), nitrification and denitrification efficiencies in P4 (middle zone) were 67%, 86% and 39%, respectively. When $PO_4^{-3}$-P concentration was analyzed in each point of the aeration tank, it was shown that $PO_4^{-3}$-P concentration coming into P2 was 1.25 mg/L, which increased to 2.22 mg/L by P release in P2 zone and then decreased to 0.74 mg/L by P uptake in P4. Consequently, we were able to estimate which high P removal efficiency observed in this study was caused by biological phosphorus removal. To determine the operating factors affecting effluent T-N, we analyzed the correlation among FN/M ratio, C/N ratio, Temp., SRT etc and these results showed that the correlation among FN/M ratio, C/N ratio and Temp was not high. However, the relationship of SRT and other parameters (effluent $NH_4^+$-N and effluent BOD) and the short SRT could have an affect on effluent $NH_4^+$-N and so effluent BOD could be increased. Thus, SRT operation should be controlled over 10 days. The results for analyzing the correlation between SRT and influent $NO_3^-$-N in order to investigate the operating factors affecting effluent T-P showed that T-P or $PO_4^{-3}$-P was not highly correlation with SRT, whereas $PO_4^{-3}$-P concentration increased along with increasing $NO_3^-$-N concentration into P2. Based on these results, we concluded, using regression analysis (R2=0.97), that effluent $PO_4^{-3}$-P concentration depends on $NO_3^-$-N concentration into P2.

• Korean Journal of Ecology and Environment
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• v.56 no.2
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• pp.127-139
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• 2023

Daechung Reservoir has been suffering from severe cyanobacterial blooming periodically due to the water pollutants from the watershed, especially nutrients from nonpoint sources. As a countermeasure, an artificial wetland was constructed to mitigate the pollutant load from the watershed by utilizing the vegetation. We investigated the water quality of the influent and outflow of the wetland during years 2014~2020 to evaluate the performance of pollutant removal through the wetland. Major pollutants (e.g. BOD, COD, SS, T-N, and T-P) were largely reduced during the retention in the wetland while nutrients removal was more efficient than that of organic matters. Pollutant removal efficiency for different inflow concentrations was also investigated to estimate the wetland's capability as a way of managing nonpoint sources. The efficiency of water treatment was significantly higher when inflow concentrations were above 75^th percentile for all pollutant, implying the wetland can be applied to the pre-treatment of high pollution load including initial rainfall runoff. Furthermore, the yearly variation of removal efficiency for seven years was analyzed to better understand long-term trends in water treatment of the wetland. The annual treatment efficiency of T-P was very high in the early stages of vegetation growth with high concentration of inflow water. However, it was confirmed that the concentration of inflow water decreased, vegetation stabilized, and the treatment efficiency gradually decreased as the soil was saturated. The findings of the study suggest that artificial wetlands can be an effective method for controlling harmful algal blooms by alleviating pollutant load from the tributaries of Daechung Reservoir.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.2
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• pp.289-294
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• 2006

A pilot scale non-woven fabric filter separation activated sludge system was investigated for practical application on domestic wastewater reclamation and reuse. The system was operated in A/O (Anaerobic/Oxic) process with submerged filter module in the aerobic compartment. In the test of two types of filter materials ($70g/m^2$ and $35g/m^2$), the initial flux (0.42m/d) could be maintained for about three months by regular air backwashing of $70g/m^2$ filter at 0.3m water head. The removal efficiency of organic matter by the system was BOD 93.3%, CODcr 96.3%, SS 96.7%. The effluent quality was 7.8mg/L, 12mg/L and 5mg/L for BOD, CODcr and SS, respectively. The water quality was enough to meet a standard for domestic reuse without human contact. T-N removal efficiency was 49.9% at internal recycle rate 2Q and C/N ratio 3.3. The removal efficiency of T-P was 50% with average effluent concentration, 2.6mg/L.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1089-1094
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• 2011

To treat non-point source pollution in Juam lake, removal efficiencies of pollutants were investigated in Bongsan constructed wetlands (CWs) at different treatment time, stages and wastewater loads. The constructed wetlands consisted of forebay, $1^{st}$ and $2^{nd}$ wetlands. The concentrations of BOD, SS, T-N, and T-P in inflow were $1.87mg\;L^{-1}$, $1.62mg\;L^{-1}$, $11.47mg\;L^{-1}$, and $4.40mg\;L^{-1}$, respectively. The removal rates of BOD, SS, T-N, and T-P in Bongsan CWs were 26, 18, 16 and 9%, respectively. The removal rates of BOD and T-N were higher than those for SS and T-P. The amounts of pollutant removal in Bongsan CWs were higher in the order of forebay > $1^{st}$ wetland > $2^{nd}$ wetland for BOD, forebay > $2^{nd}$ wetland > $1^{st}$ wetland for SS, $1^{st}$ wetland > forebay > $2^{nd}$ wetland for T-N and $2^{nd}$ wetland > forebay > $1^{st}$ wetland for T-P.

• Clean Technology
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• v.19 no.3
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• pp.295-299
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• 2013

This study was purposed and performed to evaluate removal efficiency of non-point source pollution in the process and system based on bio-retention design criteria regulated by EPA. Basic Column Reactors (BCR) were prepared for optimal determinations of inflow rate of first rainfall runoff and composition and ratio of soil layers. Removal efficiencies of non-point source pollution from synthetic runoff and real first rainfall runoff, directly sampled from motor way and parking lot, were analyzed, respectively. Removal efficiency of SS, BOD, COD, T-N, and T-P were all shown to be more than 80%.

• Journal of The Korean Society of Agricultural Engineers
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• v.49 no.2
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• pp.75-86
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• 2007

This process which has a connection of biofilter and sulfur-limestone has been developed to treat organic substances including BOD, COD and SS etc. and to treat sulfur-limestone is for denitrification.. The whole process consists of chemical reaction tank, sedimentation tank, trickling filter, denitrification tank The trickling filter is equipped with a reactor filled with absorptive filter, and the sulfur denitrification tank is filled with sulfur-limestone mixed media. After setting up practical facilities whose capacity is 60 tons a day, we have observed the removal efficiencies of pollutants through 60 experiments during Summer and Winter seasons. The average concentration of polluted water was BOD for 3.6 mg/L, $COD_{Mn}$ for 11.3 mg/L, SS for 2.8 mg/L, T-N for 8.6 mg/L, and T-P for 0.8 mg/L, and the rate of treatment efficiencies 96.5%, 84.7%, 96.5%, 79.2%, and 80.8%, respectively was found through the experiments. The average treatment efficiency for BOD and $COD_{Mn}$ was 85.0% and 55.7%, respectively and the average removal efficiency for NH4+-N was 84.9% in the trickling filter. The removal efficiency in the denitrification tank is as follows; The removal rate of $NO_3^--N$ was as high as 93.2% within the compass of pH 6.3 to 7.3 through $16.8{\sim}37.0mg/L$ flown into $NO_3^--N$ and $0.1{\sim}8.3mg/L$ outflown. It had observed that this process has implemented highly efficient and advanced treatment without external carbon sources and internal recycle during its process. In conclusion, this process is suitable for a sewerage in a small village due to the merits of low power consumption and easy maintenance.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.6
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• pp.1027-1035
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• 2000

This study was carried out to investigate the treatability of landfill leachate having high concentration of ammonium nitrogen with/without the circulation of media in pilot-scale($48m^3basis$) process. Total nitrogen removal efficiency was relatively increased in the media added process (influent ; $1.230{\sim}2,000mg{\cdot}l^{-1}$, effluent ; $120{\sim}250mg{\cdot}l^{-1}$) compared with the control process. The difference of nitrogen removal efficiency between these processes may be due to that stable growth of nitrifiers attached to the media could be achieved 99.3% of ammonium-nitrogen removal efficiency(without ; 98.2%) and 88.5% of total nitrogen removal efficiency(without ; 85.8%) were shown in media added process, respectively. Also, optimum BOD/ $NH_4{^+}$-N ratio was relatively decreased in the media process compared with the control process. Sludge settleability, on the other hand. was shown better in media added process than in control process. This outstanding sludge settleability in the media added process indicates the compatibility of media(zeolite) to the microorganism and the possibility of using media of biofilm process.

• Membrane and Water Treatment
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• v.6 no.4
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• pp.339-349
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• 2015

Experiments were carried out using granular activated carbon (GAC) adsorption techniques to treat wastewater contaminated with organic compounds caused by diverse human activities. Two techniques were assessed: adsorbent GAC prepared from coconut shell (GACC) and adsorbent GAC from palm shell (GACP). A comparison of these two techniques was undertaken to identify ways to improve the efficiency of the treatment process. Analysis of the processed wastewater showed that with GACC the removal efficiency of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity, total suspended solids (TSS) and total dissolved solids (TDS) was 65, 60, 82, 82 and 8.7%, respectively, while in the case of GACP, the removal efficiency was 55, 60, 81, 91 and 22%, respectively. It can therefore be concluded that GACC is more effective than GACP for BOD removal, while GACP is better than GACC for TSS and TDS removal. It was also found that for COD and turbidity almost the same results were achieved by the two techniques. In addition, it was observed that both GACC and GACP reduced pH value to 7.9 after 24 hrs. Moreover, the optimal time period for removal of BOD and TDS was 1 hr and 3 hrs, respectively, for both techniques.

• Journal of Korean Society on Water Environment
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• v.22 no.2
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• pp.358-363
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• 2006

KSMBR process is dynamic state advanced wastewater treatment applied with Trisectional Aeration (TSA) mode combined with membrane. TSA was remodeled conventional intermittent aeration which was operated nonaeration-aeration. TSA operates nonaeration ($N_1$) - aeration (A) - nonaeration ($N_2$) in Trisectional Aeration Reactor (TAR). Organics of influent could be nearly consumed to denitrification without influence by remained DO in TAR and it could be operated about sludge return ratio of 1Q (influent base). The purpose of this study was to apply KSMBR to the full-scale plant and to evaluate efficiency of nitrogen and phosphorus removal and TSA operation. The result of this study, average CODcr/T-N and CODcr/T-P ratio were 7.8 and 59.6, respectively. BOD, TCODcr, SS, T-N, T-P, E-coli removal efficiency were 98.4, 95.2, 73.0, 69.6, 99.95 %, respectively. KSMBR obtained high removal efficiencies of C, N and P when it applied full-scale plant.

• Journal of the Society of Disaster Information
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• v.9 no.2
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• pp.145-152
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• 2013

This study was conducted to improve the Nonpoint-source pollutant treatment plant efficiency and maintenance. Field and laboratory permeability test were conducted three times each before and after displacement. The removal efficiency such as TSS, BOD, CODmn, T-N, and T-P were investigated from the year of 2006 to 2011. The coefficient of permeability right after displacement was calculated to be $1.07{\times}10^{-3}(cm/s)$, coefficient of permeability after a year was calculated to be $0.88{\times}10^{-3}(cm/s)$, and after five years, it was calculated to be $0.3{\times}10^{-3}(cm/s)$ and accordingly, the amount of infiltration decreased. In case of the removal efficiency, it generally tended to decrease, but it showed the higher rates than the expected rates BOD 40%, SS 76%, T-N 39% and T-P 53%. It is concluded that displacement cycle should be at least five years and that dredging cycle should be at least three months and at most one year.