• 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.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.9
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• pp.940-948
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• 2006

Fluorescence measurements of dissolved organic matter(DOM) have the superior advantages over other analysis tools for applying to water quality management. They are simple and fast and require minimal pretreatment of samples. Fluorescence index($F_{450}/F_{500}$), synchronous spectra, and fluorescence excitation-emission matrices(EEM) of various DOM samples were investigated to discriminate autochthonous/allochthonous composition, protein-like fluorescence, fulvic-like fluorescence, humic-like fluorescence, terestrial humic-like fluorescence by comparing among the real DOM samples of different origins with the help of literature. The samples used included standard purified DOM, lake, river and wastewater treatment effluent. The relative distribution of various DOM composition was derived from the ratios of each fluorescence region. The results were very consistent with those expected from the sample properties. Allochthonous and terrestrial humic-like fluorescence were more prominent in the samples with abundant soil-derived DOM components. In addition, the protein-like fluorescence property was more pronounced in the samples where strong algal or microbial activities were expected. It was also shown that the ratio of protein-like/terrestrial humic-like fluorescence obtained from synchronous spectrum and fluorescence EEM could be used as an indicator for the evaluation of wastewater treatment on the downstream water quality of rivers and for the prediction of the degree of algal/microbial activities in lakes. It is expected that the results of this study will provide the basic information to develop the future water quality management techniques using DOM fluorescence measurements.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.657-668
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• 2014

Under Korea's Enforcement Decree of the Framework Act on Environmental Policy amended in 2013, total organic carbon (TOC) is newly added as water quality parameter to assess organic pollution in water and aquatic ecosystem. To meet the TOC requirement and improve quality of effluent discharged into public watershed, it is also necessary to develop standards for TOC in effluent from public sewage treatment works (PSTWs). In this study, we reviewed the characteristics and removal efficiency of TOC in influent and effluent of PSTWs. The study found that phosphorus treatment process removed not only soluble phosphorus but also a portion of TOC remaining after the secondary treatment process. TOC concentration in effluent from PSTWs operated in tandem with industrial wastewater treatment work was higher due to influx of insoluble substances from the industrial wastewater treatment work. In order to lay a foundation for the management of TOC from PSTWs, it is necessary to carry out research on TOC from different perspectives. For example, studies on the generation mechanism of TOC and the impact of TOC on drinking water resources, assessment of effluent qualities through monitoring, and development of measures to control TOC for the preservation of aquatic ecosystem are needed.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.5
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• pp.579-586
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• 2016

In many countries in order to manage corrosion of water treatment process, it is currently using Langelier index (LI). However, management of the Larson's ratio (LR) to compare corrosion management and LI which can be generated by the water treatment process is required. In this study, in order to ensure data LR, factors associated with the actual corrosion resistance of water treatment plant was measured. Using the measured data, the model equation can be estimated alkalinity, and using the statutory water quality data, LR and alkalinity is estimated. At comparison of the measured value and estimated value of alkalinity, it appeared in $R^2$ = 0.629, using the statutory water quality data and estimated alkalinity model, LR and alkalinity (Whole water treatment plants : 472) is estimated. Concentration of estimated alkalinity is 0.5 mg/L to 107.5 mg/L (average : 23.2 mg/L), and LR is 0.1 to 10 (average : 1.3). At tendency to corrosion of investigated LR, "No metal tendency" (>0.5) is 39 water treatment plants, 8.26 %, and "corrosion metal tendency" is 433 water treatment plants, 91.74%.

• Membrane and Water Treatment
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• v.11 no.3
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• pp.173-177
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• 2020

Wastewater treatment plants (WWTPs) have been recognized as one of the significant greenhouse gas (GHG) generators, due to the complex biochemical reaction and huge consumption of energy and materials. Recently, WWTPs have been built underground and they will be confronted with the challenges of mitigating GHG emissions and improving the quality of treated wastewater. Here, we focus on estimating GHG emissions to set up effective management plans for a WWTP built underground. First, we apply the process-based life cycle assessment (LCA) with an inventory database of the underground WWTP for a case study. Then, we identify significant factors affecting GHG emissions during service life using sensitivity analysis and suggest the proper tactics that could properly reduce GHG emissions from the WWTP.

• Journal of Korean Society of Water and Wastewater
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• v.36 no.3
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• pp.149-165
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• 2022

The water consumption data of individual consumers must be analyzed and forecast to establish an effective water demand management plan. A k-mean cluster model that can monitor water use characteristics based on hourly water consumption data measured using automated meter reading devices and demographic factors is developed in this study. In addition, the quantification model that can estimate the daily water consumption is developed. K-mean cluster analysis based on the four clusters shows that the average silhouette coefficient is 0.63, also the silhouette coefficients of each cluster exceed 0.60, thereby verifying the high reliability of the cluster analysis. Furthermore, the clusters are clearly classified based on water usage and water usage patterns. The correlation coefficients of four quantification models for estimating water consumption exceed 0.74, confirming that the models can accurately simulate the investigated demographic data. The statistical significance of the models is considered reasonable, hence, they are applicable to the actual field. Because the use of automated smart water meters has become increasingly popular in recent year, water consumption has been metered remotely in many areas. The proposed methodology and the results obtained in this study are expected to facilitate improvements in the usability of smart water meters in the future.

• Journal of Korean Society of Water and Wastewater
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• v.8 no.3
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• pp.34-40
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• 1994

Industrial Complex in Ulsan is one of the most important areas in the nation. It includes ship building, automobile production, petroleum industry, non-metalic industry, and related industries. However, water for drinking and industry use has been and will be short seriously. Thus available drinking water sources were searched. By rebuilding the two existing dams 20m higher than the present levels, $500,000m^3/day$(for 200days) of water sources may be produced. Additional volume of $13,000m^3/day$(for 200days) can be obtained by a number of small dam construction in the vincity area. Underground water of about $50,000m^3/day$ may also be available. The total of $680,000m^3/day$ could be produced in Ulsan area, which is enough for the population of 1,200,000 in Ulsan area even after year 2011. This newly searched volume of water may be free from pollution. Raising the dam levels may also prevent Ulsan city from chronic flooding problems. Additional advantage is that as much as the newly developed water resources can be supplied to the industrial complexes.

• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.37-44
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• 2006

Ecotoxicity assessments of 90 selected effluents of 22 industry types from 2002 to 2004 in Korea were evaluated by a toxic battery of bioassay test using fish Oryzias latipes, invertebrate Daphnia magna, algae Selenastrum capricornutum and bacteria Vibrio fischeri with the physicochemical measurement items and permit concentrations on the present Water Quality Conservation Act in Korea. Total toxic unit (${\Sigma}TU$) of 8 industry types of 22 industry types by the toxic battery appeared in order of the value site as follows; Pigment Dye Manufacturing (${\Sigma}TU$ 217.1) > Textile and Dye (${\Sigma}TU$ 39.3) > Semiconductor Electronic Manufacturing (Small) (${\Sigma}TU$ 25.6) > Wastewater and Sewage Treatment Plants (${\Sigma}TU$ 25.4) > Coating (${\Sigma}TU$ 23.8) > Leather Skin Manufacturing (${\Sigma}TU$ 18.0) > Synthetic Resin Manufacturing (${\Sigma}TU$ 15.6) > Assemble Metal Manufacturing (${\Sigma}TU$ 10.7). Our results demonstrate that ecotoxicity assessment, by bioassay test, is effective and practical for industrial wastewater management for 90 selected effluents with the limitation of the physicochemical permit. Among 90 effluents, 9 samples failed physicochemical permit limitation and 81 passed it. In result of ecotoxicity assessment of 90 effluents by the toxic battery, 76 effluents exhibited ecotoxicity and the others did not. The physicochemical measurement items and permit concentrations on the present Water Quality Conservation Act in Korea were low related to the ecotoxicity value by the toxic battery and appeared limited for water quality management to water-ecosystem and environment-friendly management of water.

• Journal of Korean Society on Water Environment
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• v.22 no.5
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• pp.807-814
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• 2006

Sapkyo Lake Watershed occupies about 19.3% of total area of Chungnam Province, and it is necessary to make a plan of counter-measure for the maintenance of public waterbody sound as well as to ensure water resources due to urbanization and industrialization in this area so densely populated and excessively developed. Conventionally water quality management has been enforced by concentration-based system which is not considered the carrying capacity of receptors, hence there are no proper measures for the prevention of an excessive pollutant load over a waterbody. So even though emission sources abide by the conventional permission regulation, then the quantity of wastewater is increased continuously and encountered water shortage to use finally. Therefore this research focused on the review of introduction of total water quality management system in Sapkyo Lake watershed to maintain public waterbody sound and to ensure water resources. By doing this research in introduction of the system in advance, it can contribute to establish the methodology on systematic water quality management. Also the application of this system in Sapkyo Lake watershed can promote the sustainable development of the area by harmonizing the environment and regional economy ultimately.

• Journal of Korean Society of Water and Wastewater
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• v.23 no.2
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• pp.251-255
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• 2009

Foreign and domestic seawater desalination plant market investigation was performed to analyze the worldwide trend of seawater desalination plant market and to establish the activation plan for seawater desalination plant application. Water demand and seawater desalination related laws and regulations were investigated and analyzed for the activation plan. RO type and large scale plants are popular nowadays however there are only small plants in island region in Korea. There will be about $1 million\;m^3/day$ deficit in 2015 according to the water demand forecasting from Ministry of Environment and Ministry of Land, Transportation, and Maritime Affairs in Korea. Therefore, it is necessary to activate the domestic application of seawater desalination plant to secure stable water resources. To activate the domestic application of seawater desalination plant, first, we need to establish regulations, support system in the water service law for seawater desalination plant. Second, related Ministry should increase the support for the operation and management of seawater desalination plant and suggest the construction of seawater desalination plant for water resources security near seaside region.