• Journal of Korean Society on Water Environment
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• v.22 no.1
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• pp.166-171
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• 2006

The objectives of the present paper were to investigate the concentration of total coliform in wastewater effluents and the effect of water chemical and physical characters in it. The most correlated parameter with total coliform was COD. It means that the wastewater treatment efficient effects on total coliform concentration. And we developed predictive model for the total coliform concentration. The estimated parameters for model were COD, temperature, nitrite, chloride, Mn and regression model equation was determined; log (Total Coli.) = 1.861+0.065[COD]+0.038[temperature]-0.0004[$Cl^-$]+3.697[Mn]-0.32 [$NO_2-N$] The developed model provided very strong correlation ($R^2:0.82$) between total coliform and regression equation. The parameters having high sensitivity were COD and temperature. So the study indicated that if the temperature and COD of wastewater effluent were known, we would estimate the concentration of total coliform and decide the most effective usage of chlorine.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.3
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• pp.435-441
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• 2015

Relationships among different stress parameters (lairage time and blood level of lactate and cortisol), meat quality parameters (initial and ultimate pH value, temperature, drip loss, sensory and instrumental colour, marbling) and carcass quality parameters (degree of rigor mortis and skin damages, hot carcass weight, carcass fat thickness, meatiness) were determined in pigs (n = 100) using Pearson correlations. After longer lairage, blood lactate (p<0.05) and degree of injuries (p<0.001) increased, meat became darker (p<0.001), while drip loss decreased (p<0.05). Higher lactate was associated with lower initial pH value (p<0.01), higher temperature (p<0.001) and skin blemishes score (p<0.05) and more developed rigor mortis (p<0.05), suggesting that lactate could be a predictor of both meat quality and the level of preslaughter stress. Cortisol affected carcass quality, so higher levels of cortisol were associated with increased hot carcass weight, carcass fat thickness on the back and at the sacrum and marbling, but also with decreased meatiness. The most important meat quality parameters (pH and temperature after 60 minutes) deteriorated when blood lactate concentration was above 12 mmol/L.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.731-739
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• 2007

In this study, water quality monitoring focused on TOC was performed at 5 points in Mihocheon (Stream) from January to December 2006. And 10 parameters (water temperature, pH, DO, EC, turbidity, SS, BOD, $PO_4-P$, TOC, TN) were monitored every month for one year. According to this study, TOC increased towards the lower stream (#4~#5). Correlation coefficients between TOC and DO, EC, turbidity, SS, BOD, $PO_4-P$, TN were -0.126, 0.351, 0.320, 0.286, 0.711, 0.525, 0.666. TOC was highly related to BOD. As a result of linear regression analysis, regression equation between BOD and TOC was BOD=0.58TOC+1.90 ($R^2=0.506$). In Mihocheon (Stream), BOD/TOC ratio decreased towards the lower stream. This results show decrease of ratio of biodegradable organic material to total organic pollutants towards the lower stream. This study is significant since it has revealed the potential value of TOC as organic material indicator for inquiry of water quality characteristics in the natural water system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.13 no.2
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• pp.295-305
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• 1993

The purpose of this study is to investigate the theoretical methodology for development of an water quality management system with the optimal control of dilution water and point sources in streams. For the development of objective function and constraints, the control vectors are defined with stream inflows and concentrations of effluents at water treatment plant, and the state vectors are defined with water quality parameters such as DO, $BOD_5$, COD and SS concentrations. The applied system solution technique is augmented Lagrangian technique. The developed water quality optimal management methodology was applied to a case study at the Musim stream in Cheong-ju city. The results of the application show that the methodology is suitable for the comprehensive analysis of polluted water systems, and will be utilized to more useful operation of limited water resources in Korean streams.

• Membrane and Water Treatment
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• v.8 no.6
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• pp.529-541
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• 2017

A multi-effect air gap membrane distillation (ME-AGMD) module for pesticide wastewater treatment is studied with internal heat recovery, sensible heat of brine recovery, number of stages and the use of fresh feed as cooling water in a single module is implemented in this study. A flat sheet polytetrafluroethylene (PTFE) membrane was used in the 4-stage ME-AGMD module. The maximum value of permeate flux could reach $38.62L/m^2h$ at feed -coolant water temperature difference about $52^{\circ}C$. The performance parameter of the module like, specific energy consumption and gain output ratio (GOR) was investigated for the module with and without heat recovery. Also, the module performance was characterized with respect to the separation efficiency of several important water quality parameters. The removal efficiency of the module was found to be >98.8% irrespective water quality parameters. During the experiment the membrane fouling was caused due to the deposition of the salt/crystal on the membrane surface. The membrane fouling was controlled by membrane module washing cycle 9 h and also by acidification of the feed water (pH=4) using 0.1M HCl solution.

• Environmental Engineering Research
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• v.10 no.2
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• pp.62-70
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• 2005

Pollution loading of Combined Sewer Overflows (CSOs) is frequently over the capacity of a wastewater treatment plant (WWTP) receiving the water. The objectives of this study are to investigate water quality of CSOs in Anmyun-ueup, Tean province and to apply Storm Water Management Model to predict flow rate and water quality of the CSOs. The capacity of a local WWTP was also estimated according to rainfall duration and intensity. Eleven water quality parameters were analyzed to characterize overflows. SWMM model was applied to predict the flow rate and pollutant load of CSOs during rain event. Overall, profile of the flow and pollutant load predicted by the model well followed the observed data. Based on model prediction and observed data, CSOs frequently occurs in the study area, even with light precipitation or short rainfall duration. Model analysis also indicated that the local WWTP’s capacity was short to cover the CSOs.

• Journal of Korean Society on Water Environment
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• v.22 no.3
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• pp.456-461
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• 2006

The facility of constructed wet land combined with filter media was examined in order to improve the water quality of a polluted stream, which has been performed as a part of national projects. Throughout 2 years of operation for a stream, it can provide the design and operating parameters for the purpose of future construction. The influent flow rate was about 50% against the design capacity. The removal efficiencies of BOD, $COD_{Mn}$, SS, T-N and T-P were 62.9%, 47.1%, 74.8%, 22.4% and 33.5%, respectively. In order to keep this facility stable, the removal of surface filter media and supplement should be periodically conducted. In addition, the proper selection of sites is recommended not to be flooded.

• Korean Journal of Ecology and Environment
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• v.43 no.4
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• pp.459-470
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• 2010

In this study, we analyzed fish tolerance guilds in mainstems and tributaries of 65 streams and rivers arid their relations to water quality using dataset sampled from April to November, 2009. For the study, water quality parameters including biochemical oxygen demand (BOD), electric conductivity (EC), total nitrogen (TN), total phosphorus (TP), ammonia nitrogen ($NH_3$-N), nitrate nitrogen ($NO_3$-N) and phosphate phosphorus ($PO_4$-P) were analyzed in the laboratory and also tolerance ranges in 3 category fishes of sensitive, intermediate, and tolerant species with high abundance were analyzed. According to fish guild analysis, tolerant species was 58% of the total community and the proportion of omnivore species was 63% of the total, indicating a degradation of habitats and water quality. Water quality was shown typical longitudinal gradients from the headwater to the down-river; TN and TP increased toward the down-rivers except for the big point-source area and ionic contents, based on, electric conductivity showed same pattern. Tolerance guild analysis of 9 major species with high abundance indicated that sensitive groups had narrower tolerance range in the water quality than the groups of intermediate and tolerant species. In contrast, tolerant groups including Zacco platypus, Carassius auratus, and Opsarichthys uncirostris amurensis had wider tolerance ranges than the groups of sensitive and intermediate species. Thus, each group was evidently segregated from the tolerance levels. Principal Component Analysis (PCA) employed for the relations of water quality to fish species in each groups suggests that water quality had highest eigenvalues with fish species in the 1st axis of the PCA and nitrogen (TN, $NH_3$-N, $NO_3$-N) and phosphorus (TP) were key components differentiating three groups of sensitive, intermediate and tolerance guilds.

• Spatial Information Research
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• v.14 no.2 s.37
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• pp.223-234
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• 2006

In order to examine spatio-temporal characteristics of coastal water quality, we applied GIS spatial analysis to the water quality data collected from observation points located on Korean coastal area during 1997$\sim$2004. The water quality parameters measured included: chlorophyll-a, pH, DO, COD, SS, dissolved inorganic nitrogen, dissolved inorganic phosphorous, salinity, temperature. The water quality data used in this paper was obtained only at selected sites even though they are potentially available at any location in a continuous surface. Thus, it is necessary to estimate the values at unsampled locations so as to analyze spatial distribution patterns of coastal water quality, Owing to this reason, we applied IDW(inverse distance weighted) interpolation method to water quality data and evaluated the usefulness of IDW method. After IDW interfolation method was applied, we divided the Korean coastal area into 46 sections and examined spatio-temporal patterns of each section using GIS visualization technique. As a result of evaluation, we can blow that IDW interpolation and GIS are useful for understanding spatial and temporal distribution characteristics of coastal water quality data which is collected from a wide area far many years.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1228-1237
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• 2005

In order to predict the long-term effects of pollutants in sediment on the water quality and the improvement of water quality according to dredging operation, models applied to decide the location and the propriety of dredging were developed. At first, the area was divided into several segments and the developed model was applied to simulate the behaviors of contaminants in an aquatic environment by using estimated parameters. And then through the sensitivity analysis between parameters, the optimum values were determined. The long-term modelling in the area A forecasted that PCBs concentration in the hot spot was decreased from $3.1\;{\mu}g/L$ to $2.4\;{\mu}g/L$ in 30 years. Contaminants in sediment as a source of water pollution did not reduce remarkably in the long run. Therefore it is difficult to expect the improvement of water qualities without the fundamental isolation of contaminants from sediment. It is considered that the selective dredging in the spot improves the water quality consequently.