• Korean Journal of Ecology and Environment
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• v.49 no.2
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• pp.124-129
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• 2016

This study was conducted to suggest the cause analysis and mitigation measures of foaming generated in the effluent of wastewater treatment plant. The foam generated in the outlet connected with the tidal river system was identified as structural problems. And the main cause of foaming was air entrainment by an impinging jet and the internal accumulation by the diffusion barrier. In consideration of these conditions, it present the effective ways such as micro-screen and submerged outlet, to mitigate the foaming generated in the water channel and outlet end.

• Journal of Electrochemical Science and Technology
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• v.13 no.2
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• pp.261-268
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• 2022

In this study, electrochemical treatment of urban wastewater with electrical conductivity of 1000 μS cm^-1 and chemical oxygen demand of 250 mg L^-1 was investigated using the variables of initial pH value, current density and flow rate. Electrocoagulation was used, in which aluminum and stainless steel were selected, as the electrochemical treatment process. The electrocoagulation process was operated in continuous mode. The data obtained in experimental studies show that the best COD removal efficiency occurred in experiments where the initial pH value was 6. The increase in current density from 5 A to 15 A decreased the removal efficiency from 79 to 67%. The increase in flow rate under constant current density also reduced the efficiency of removal as expected. In experiments in which current density and flow rate were examined together, the increase in flow rate allowed the application of higher current densities. This situation led to considerable reductions in energy consumption values, even if the COD removal efficiency did not significantly increase. The high COD removal obtained with the use of high flow rate and high current density indicates that the electrocoagulation process can be used for high flow rate municipal wastewater treatment.

• Journal of Environmental Science International
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• v.20 no.6
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• pp.673-678
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• 2011

Water samples from several wastewater treatment plants and two industry drains in Gyeongsangbukdo were investigated for concentration levels of micropollutants. Samples were taken totally four times from May to November of 2008 and tested for seven factors including pesticide, 1,4-Dioxane and Perchlorate which had been big issues for Nakdong river because of their contaminations. As results, 2,4-D, Alachlor, and BEHA were not detected while BEHP was detected at some sampling sites. 1,4-Dioxane and Perchlorate were also detected in wide ranges from several sampling sites. Therefore, continuous supervising and monitoring systems needed to be invested for proper management for micropollutants since those micropollutants could affect human health and aquatic system with low concentration levels.

• Environmental Engineering Research
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• v.20 no.4
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• pp.392-396
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• 2015

This work aims to investigate the oily wastewater treatment by the electrocoagulation-flotation (ECF) and propose a mathematical model for the efficiency prediction. Cutting oil was used to prepare the synthetic oily wastewater with submicron droplet sizes. The chemical coagulation by aluminium sulfate was firstly tested following by the electrocoagulation-flotation with aluminium electrodes. Both processes gave the effective treatment performance with the efficiencies higher than 90%. However, the ECF consumed less aluminium dosage as well as produced less sludge, which were its advantage on the chemical coagulation. The performance of the ECF was found to be affected by the current density, oil concentration, and reaction time according to the analysis by the design of experiment (DOE). Finally, the prediction model was proposed by two approaches, including linear and logarithm function. The latter model gave more accuracy prediction results in terms of treatment efficiency and duration in the lag and stable stages.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.5
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• pp.698-701
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• 2000

To prevent surface and underground water pollution, wastewater treatment is essential. Four bench-scale activated sludge units (10 L operational volumes) were operated at 5, 10 and $20^{\circ}C$ for evaluation of treatment efficiencies with typical wastewater from swine housing. The units were set for a 24-hour cycle. As compared to the conventional process, high removal efficiencies for organic substances, nitrogen and phosphorus in swine wastewater were obtained simultaneously with an intermittent aeration process (lAP). The NOx-N produced during an aeration period was immediately reduced to nitrogen gas (e.g. $N_2$ or $N_2O$) in the subsequent non-aeration periods, and nitrification in aeration periods occurred smoothly. Under these conditions, phosphorus removal occurred with the release of phosphorus during the non-aeration periods followed by the excess uptake of phosphorus in the activated sludge during aeration periods. It was confirmed that the lAP had a better ability to remove pollutants under both low temperatures and high nitrogen loading conditions than the ordinary method did. In addition to that, the total emission of $N_2O$ from lAP was reduced to approximately 1/50 of the conventional process for the same loading. By adopting an adequate aeration programme for individual swine wastewater treatment, this system will provide a promising means for nitrogen and phosphorus control without pH control or addition of methanol.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.273-283
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• 2014

With the introduction of COBie (Construction Operation Building Exchange) in BIM technology enabling an automatic transfer of design and construction information to operation and management (O&M) phase, the BIM centric O&M management system development process has been tested on the subject of architectural types of building. However, for now, there is a need to investigate the technical feasibility of COBie application to civil structures including industrial facilities. This study takes both "O&M Guideline for Public Wastewater Treatment Plant" and a real wastewater treatment plant into account for the purpose, in which the latter is intended to supplement the result of the first. The findings are three-folds: (1) COBie, as an asset modeling, is not sufficient enough to encompass commissioning data, (2) more relevant IFC development and family library build-up useful to modeling wastewater treatment plant is imperative, and (3) well-planned coordination and organization of COBie data-set in line with O&M practice will enhance the feasibility of the COBie in industrial facilities. The result could be used for a basis study for COBie application, particularly in industrial facilities.

• Journal of Korean Society of Water and Wastewater
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• v.12 no.3
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• pp.41-47
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• 1998

Doam Lake is located around the pasture area and Yongpyung Resort. Because of the waste load of domestic animals, nutrient concentration of the stream is high. In this study, waste load of Doam Lake watershed is calculated, and QUAL2E model is applied to the upper part of the Songcheon to calculate the input boundary concentration of Doam Lake. And WASP5 model is applied for the water quality modeling of Doam lake. The results indicate that advanced treatment of domestic animal wastes is necessary for the lake water quality management.

• Journal of Environmental Science International
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• v.21 no.10
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• pp.1245-1253
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• 2012

In this study, how branches of Kumho River affect to the water quality on Kumho River was investigated. Water samples from six sampling points at Kumho River and three at each branch were taken from Dec. 2009 to Dec. 2011. As results, Namcheon affected BOD and T-P concentrations on Kumho River while Sincheon did only T-P concentrations. However, the water quality of Kumho River was improved because of Sincheon in terms of BOD and COD concentrations. This was the results from management of Sincheon wastewater treatment facility and Jisan wastewater treatment facility which might be the best example for managing wastewater treatment facilities. Dalsecheon would not affect the water quality of Kumho River although it had bad conditions of water quality because of lack of its water quantity comparing to Kumho River's.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.6
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• pp.665-672
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• 2008

It is necessary to implement the management plan for the production of safe and high quality drinking water from lake Paldang. To set up the plan, the water quality items such as BOD, T-P, SS and coliform were monitored for ten years, 1997~2006, and the influence of raw water quality on the drinking water treatment process and the treated water quality was also evaluated from 2004 to 2006. In conclusion, water quality items such as turbidity(SS), T-P(eutrophication), pathogens(fecal coliforms, enterovirus, reovirus, giardia, cryptosporidium), DOC(precursor of disinfection by-products), and micro-pollutants(phthalates, VOCs, heavy metals) are should be managed to get safe and high quality drinking water from lake Paldang.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1443-1450
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• 2015

Wastewater treatment plant(WWTP) has been recognized as a high energy consuming plant. Usually many WWTPs has been operated in the excessive operation conditions in order to maintain stable wastewater treatment. The energy required at WWTPs consists of various subparts such as pumping, aeration, and office maintenance. For management of energy comes from process operation, it can be useful to operators to provide some information about energy variations according to the adjustment of operational variables. In this study, multiple regression analysis was used to establish an energy estimation model. The independent variables for estimation energy were selected among operational variables. The $R^2$ value in the regression analysis appeared 0.68, and performance of the electric power prediction model had less than ${\pm}5%$ error.