• Journal of Wetlands Research
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• 제16권1호
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• pp.51-59
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• 2014

A sewage was treated using serially combined vertical and horizontal flow zeolite-filled reed bed. The sewage from the student dormitory of Changwon National University was fed into the reed bed for 10 minutes every 6 hours at the hydraulic load of 314 $L/m^2{\cdot}day$. The reed bed depth was 100cm and the zeolite mixture was filled in the reed bed. The mixture consisted of the same volume of two types of zeolite ; 0.5~1mm and 1~3mm in diameter. pH value decreased in vertical bed, while it increased in horizontal bed. But DO concentration in the effluent of both beds was higher than that in the influent. Average removal efficiencies of the entire treatment system were 99.22% SS, 95.56% BOD, 91.02% $COD_{Cr}$, 87.78% $COD_{Mn}$, 45.87% T-N, 99.88% $NH{_4}^+-N$ and 71.17% T-P. Most of T-N in the effluent was $NO{_3}^--N$. However, the concentration of $NO{_2}^--N$ in the effluent was lower than 0.04 mg/L. All removal efficiencies did not show a remarkable seasonal change.

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.104-110
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• 2019

Since 1986, domestic sewage treatment plants have installed and operated biogas plants that produce biogas (digested gas) using food, livestock manure and sewage sludge as part of the use of alternative energy for energy independence. Despite concerns about safety accidents and risks of large-scale accidents due to the continuous expansion of biogas plants, the Ministry of Environment has managed and supervised biogas plants to be environmental plants, focusing on environmental management. There is a lack of safety awareness of workers' processes. Only recently has the process safety management (PSM) system been implemented in biogas plants, but workers' perceptions of process safety have changed. As there is a difference in the degree of safety process management and safety awareness among workers, it is necessary to establish clear and systematic safety management standards. Therefore, The purpose of this study is to examine whether the application of the plant safety management (PSM) system to biogas plants is effective for workers' safety awareness in order to ensure safe operation of biogas plants and prevent workers' safety accidents in advance.

• Journal of the Korean Society of Environmental Restoration Technology
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• 제7권2호
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• pp.68-74
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• 2004

A blast furnace slag(BFS) has been used as a filter medium for the treatment of domestic waste waters during the period of 9-month. More than 90% of phosphorus was removed while the hardness of the treated water increased by 5 times and the pH was significantly raised from 6.8 to 10.8. The high hardness and pH of the treated water indicated dissolution of BSF by the sewage. The experimental results suggest that BFS could be utilized for the removal of phosphorus in the waste water treatment plant using aquatic plants and gravels.

• Journal of Korean Society of Environmental Engineers
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• 제29권8호
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• pp.876-883
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• 2007

• Journal of the Korean Society for Marine Environment & Energy
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• 제3권3호
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• pp.41-49
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• 2000

When sewage and industrial wastewater are treated to improve the coastal water quality, we usually consider the reduction of BOD and/or COD. Due to the inflow of untreated nitrogen and phosphorus, however, the coastal water has eutrophicated. Thus, to improve the water qualify, it is necessary to treat and reduce nitrogen and phosphorus which are the factors limiting algal growth. Hence, with regard to the adaption of Ocean Outfall for the treatment of wastewater in Suyoung Bay, we studied the effectiveness and environmental assessment of Ocean Outfall of which cost is lower than that of advanced treatment, The effectiveness of Ocean Outfall of the second treatment effluent in Nambu S.T.P. was simulated, using the eco-hydrodynamic model as far field model the result showed that the water quality of coastal area receiving wastewater on the surface sea has improved. But the concentrations of nitrogen and phosphorus around the diffuser of Ocean Outfall system can cause many problems on estuary, such as red tide, eutrophication and aquatic toxicity.

• Journal of Korean Society on Water Environment
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• 제37권2호
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• pp.128-136
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• 2021

It is generally known that a wastewater treatment plant (WWTP) consumes immense energy even if it can produce energy. With an aim to increase the energy independence rate of WWTP from 3.5% in 2010 to 50% in 2030, the Korean government has invested enormous research funds. In this study, cost-effective operating alternatives were investigated by analyzing the energy efficiency and economic feasibility for biogas and power generation using new and renewable energy. Based on the US EPA Energy Conservation Measures and Korea ESCO projects, energy production and independence rate were also analyzed. The main energy consumption equipment in WWTP is the blower for aeration, discharge pump for effluent, and pump for influent. Considering the processes of WWTP, the specific energy consumption rate of the process using media and MBR was the lowest (0.549 kWh/㎥) and the highest (1.427 kWh/㎥), respectively. Energy-saving by enhancing anaerobic digester efficiency was turned out to be efficient when in conjunction with stable wastewater treatment. The result of economic analysis (B/C ratio) was 2.5 for digestive gas power generation, 0.86 for small hydropower, 0.49 for solar energy, and 0.15 for wind energy, respectively. Furthermore, it was observed that the energy independence rate could be enhanced by installing energy production facilities such as solar and small hydropower and reducing energy consumption via the replacement of high-efficiency operating.

• Journal of Korean Society on Water Environment
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• 제22권2호
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• pp.230-237
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• 2006

The operational parameters and control strategies of a tertiary wastewater treatment process a biological filtration system were investigated. The biological filtration system consisted of a nitrification filter (Fiter 1) and a polishing filter with anoxic and aerobic parts (Filter 2). SS, T-C-BOD, and T-N in effluent were kept stable at less than 3, 5 mg/L, and 5 mgN/L, respectively, under a HRT in Filter (filter-bed) of 0.37~2.3 h. T-N at the outlet of Filter 2 were about 1~5 mgN/L under the condition of LV of 50~202 m/d. Methanol addition was controlled based on the COD/N ratio or McCarty's equation. Constant COD/N ratio control results in excess addition under large diurnal fluctuation of $NOx^--N$, and McCarty's equation can be used to add appropriate amount of methanol. Control of methanol addition by on-line nitrate measurement, control of aeration by on-line DO measurement, and control of backwashing by head loss measurement are successfully operated. These results proved that this process prove the easy-maintenance and cost-effectively treatment is attainable.

• Journal of the Korean Institute of Telematics and Electronics B
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• 제31B권6호
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• pp.43-52
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• 1994

A design method of rule-based fuzzy modeling is presented for the model identification of complex and nonlinear systems. The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of ``IF....,THEN...', using the theories of optimization theory , linguistic fuzzy implication rules and fuzzy c-means clustering. Three kinds of method for fuzzy modeling presented in this paper include simplified inference (type I), linear inference (type 2), and modified linear inference (type 3). In order to identify premise structure and parameter of fuzzy implication rules, fuzzy c- means clustering and modified complex method are used respectively and the least sequare method is utilized for the identification of optimum consequence parameters. Time series data for gas furance and those for sewage treatment process are used to evaluate the performance of the proposed rule-based fuzzy modeling. Comparison shows that the proposed method can produce the fuzzy model with higher accuracy than previous other studies.

• Journal of Wetlands Research
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• 제1권1호
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• pp.1-5
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• 1999

We could know that the Woopo and Mokpo wetlands, which have the typical colony structure in the agricultural area of korea, had a characteristic which the pollution sources of water are scattered widely and it is caused by sewage, livestock wastewater and non point sources. As the result of an examination of water, the concentration of T-N was measured highly within five grade in the lake standard. If we build natural domestic treatment system in Taehap-myon, lbang-myon and Yuo-myon, which are located at the upper stream of wetlands, we can remove SS, BOD, COD and T-N largely.

• Korean Journal of Microbiology
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• 제37권2호
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• pp.124-129
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• 2001

For elucidating the effect of salinity to the effect of wastewater treatment, the heterotrophic bacterial numbers, total bacterial numbers, and the bacterial community structure by FISH method were analyzed. The total bacterial numbers were not significantly changed by the salinity. But the heterotrophic bacterial numbers and bacterial community structures were drastically changed by the increase of salinity. In case of 1% salinity, the heterotrophic bacterial numbers and structure were slightly changed comparing to those of contol. In case of 2% and higher salinities, the numbers of heterotrophic bacteria and the proportions of Eubacteria, Proteobacteria $\alpha$-group, $\rho$-group and Cytophaga-Flavobacterium groups were deceasing. By these results, the salinity stress to bacterial community in waste water treatment was unveiled, and for sustaining the waste water treatment system, the salinity should be lower than 1%.