• Journal of Korean Society on Water Environment
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• v.23 no.2
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• pp.236-243
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• 2007

Fluorescence measurements of dissolved organic matter (DOM) have the superior advantages over other analysis tools for the applications to water quality management due to their rapid analysis. It is known that protein-like fluorescence characteristics are well corelated with microbial activities and biodegradable organic matter. In this study, potential biochemical oxygen demand (BOD) predictor were explored using the fluorescence peak intensities and/or the integrated fluorescence intensities derived from synchronous fluorescence spectra and the first derivative spectra of river samples. A preliminary study was conducted using a mixture of a river and a treated sewage to test the feasibility of the approach. It was demonstrated that the better BOD predictor can be derived from synchronous fluorescence spectra and the derivatives when the difference between the emission and the excitation wavelengths (${\Delta}{\gamma}$) was large. The efficacy of several selected fluorescence parameters was rivers in Seoul. The fluorescence parameters exhibited relatively good correlation coefficients with the BOD values, ranging from 0.59 to 0.90. Two parameters were suggested to be the optimum BOD predictors, which were a fluorescence peak at a wavelength of 283 nm from the synchronous spectrum at the ${\Delta}{\gamma}$ value of 75 nm, and the integrated fluorescence intensity of the first derivatives of the spectra at the wavelength range between 245 nm and 280 nm. Each BOD predictor showed the correlation coefficients of 0.89 and 0.90, respectively. It is expected that the results of this study will provide important information to develop a real-time efficient sensor for river BOD in the future.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.201-208
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• 2012

Wangsong Reservoir needs a systematic approach that can control water purity and water quality improvement. This study was carried out to assess the seasonal variation of water quality and the effect of pollutant being loaded from watershed in a sallow eutrophic reservoir(Wangsong Reservoir) from March to November, 2011. Wangsong Reservoir, located in Uiwang City, has the capacity of 2 million $m^{3}$ in irrigation water supply with the drainage of 4.2 $km^{2}$. Average concentrations of BOD, COD, T-N, T-P, and Chloropyll-a in Wangsong Reservoir were 5.8 mg/L, 9.7 mg/L, 4.299 mg/L, 0.106 mg/L and 73.1 mg/$m^{3}$, respectively. In the inflow streams and treated sewage of Wangsong Reservoir, the T-N concentrations of 4.114 - 14.619 mg/L were higher than those in the Reservoir and the other pollutants were lower. As a result of investigation, Wangsong Reservoir exceeded the agricultural water standard level due to algal growth and accumulation from the upper streams and sewage. In order to achieve the targeted water quality in Wangsong Reservoir, it is required to be decreased in pollutants of internal and inflow streams.

• Proceedings of the SAREK Conference
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• 2007.06a
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• pp.15-15
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• 2007

• Journal of The Korean Society of Agricultural Engineers
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• v.53 no.4
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• pp.59-65
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• 2011

The purpose of this study was to analyze the water quality change when wastewater applied to study paddy fields. CREAMS-PADDY (Chemical, Runoff and Erosion from Agricultural Management System) model was used to estimate the field-scale water quality. Simulated results were compared with observed data monitored from Byeongjeom study paddy fields which is located near the Suwon sewage treatment plant in Gyeonggi-do. Significance analysis was performed for the three different irrigation water quality level and five fertilizer reduction scenarios using LSD (Least Significant Difference) and DMRT (Duncan's Multiple Range Test). Total nitrogen was found to be significant for both irrigation water quality level and fertilizer reduction while total phosphorus was not. Annual drainage load for total nitrogen was reduced by 66~92 % compared to irrigation load when treated wastewater irrigated to study paddy fields from 2002 to 2007. Total phosphorus was reduced by 70~86 %.

• Journal of Korean Society of Water and Wastewater
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• v.22 no.5
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• pp.505-510
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• 2008

Excess sludge and raw sludge were treated by ball mill in order to promote solubilization, and it was known that the level of solubilization was higher in excess sludge rather than raw sludge. About solid concentration, with the increase of TS, the amounts of solubilization was increased. And excess sludge was solubilized more effectively with the increase of ball mill treatment time. Especially, in case of excess sludge, within 5 min of ball mill treatment, 6 times of solubilization was achieved compared with raw sludge. The effect of bead size was also tested and 1 mm bead was most desirable when applied to the TS 4% of excess sludge. Particle size decrease by the ball mill treatment was more effective in raw sludge, nevertheless the level of solubilization was always higher in excess sludge. This means that the results of particle analysis could not be understood as a indicator for sludge solubilization. Generally, excess sludge and raw sludge are mixed at the thicker in the STP, but considering a ball mill pretreatment as an alternative for sludge solubilization, it is desirable to treat not raw sludge but excess sludge alone in the aspect of solubilization yield and economical process.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.3173-3177
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• 2007

Recently, we have many problems on the process of the sludge. In past, the sewage sludge was treated by reclaimed land or thrown away in the sea. But these methods caused environmental pollution. Today, many researchers are studying various methods for reducing its volume. One of these method, this study is to reduce the moisture of sewage sludge and to solidify it using a dryer and curing equipment. In this research, we investigated about design parameter and operation condition of the equipment. The curing equipment reduces the percentage of water content from 30% of dryer to 10%. So, we have to study the curing characteristics and performance of curing equipment. For example, there are internal flow characteristics and change of the percentage of water content. And we investigated the change of data at outlet along the initial condition, temperature, humidity and air flow. Using this data, we achieve the experimental results of curing efficiency by each geometry and operating condition. And we also investigated numerical analysis of internal flow using CFD code. This research is basic study for optimal design of the curing equipment.

• Journal of Korean Society of Water and Wastewater
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• v.18 no.5
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• pp.619-627
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• 2004

Purposes of this study were to examine closely the extracellular polymeric substances (EPS) which was a membrane fouling contaminant, to control detected EPS by powdered activated carbon (PAC) dosage etc. and to evaluate the possibility of practical reuse facility. With high removal efficiency of general pollutants, when the PAC is added to MBR, improvement of removal efficiency of $COD_{cr}$, and color was expected and treated wastewater can be reused. It was judged that the correlation between EPS and membrane fouling was very high. Carbohydrate and DNA in the EPS were judged to be cause of membrane fouling. If EPS could be controled, not only membrane fouling would be decreased but also operation time would be extended. In experiment of powdered activated carbon (PAC), characteristics of the best PAC for membrane fouling control were the particle size of $7{\mu}m$, lodine Number of 1,050, surface area of peat of $1,150m^2/g$. In lab test, operation time of MBR by PAC dosage of 200mg/gVSS was longer than one of MBR by without PAC dosage. Because EPS, especially carbohydrate and DNA, was controled successfully by PAC, membrane fouling in MBR could be decreased.

• Journal of Korea Water Resources Association
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• v.46 no.12
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• pp.1169-1180
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• 2013

The objectives of this study are to construct the natural streamflow in the Bokhacheon middle-upper watershed using the SWAT-K model and to assess the impacts of groundwater withdrawals, water intake, treated sewage water release on streamflow. The simulated natural streamflow from 2006 to 2013 showed the minimum discharge of $1.7m^3/s$, the annual average discharge of $26.2m^3/s$, the drought flow of $2.0m^3/s$ at the outlet of the study area. The simulated results indicated that the groundwater pumping has induced the decrease of 34% in drought flow against the natural condition and the net water release has caused the increase of 15%, while the combined effects of the groundwater pumping and the net water release have induced the decrease of 19%. It was found out from the simulated natural streamflow data that the specific discharges of the abundant flow, normal flow, low flow, drought flow in the upper-middle channels of the Bokha-cheon watershed have a tendency to increase as the drainage area increases, but the specific discharges showed almost constant values at any downstream point with drainage area more than about 180 $km^2$.

• ALGAE
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• v.23 no.3
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• pp.219-230
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• 2008

The structure of phytoplankton community was studied for one year round at 6 stations in the Beopsu Marsh, Haman-gun, Gyeongsangnam-do, Korea. One hundred seventy-eight taxa (69 taxa belonging to Chlorophyta, 55 taxa to Bacillariophyta, 33 taxa to Cyanophyta, 15 taxa to Euglenophyta, 2 taxa to Rhodophyta, 2 taxa to Dinophyta and 1 taxon to Xanthophyta) were observed. Phytoplankton bloom occurred at the staions 2, 3 and 4 where waters were polluted by sewage and treated water of purification plants from the vicinity. The species diversity index of phytoplankton was the lowest (0.66) in November at the station 3, which the station showed the most eutrophic water due to the diverse pollutants from surroundings of the marsh. For the whole seasons, Fragilaria sp. and Euglena sp. appeared in pollutant water at the station 3, while Cyclotella sp. and Pinnularia sp. inhabited in relatively clean water at the station 5. To reserve the natural treasure, the wetland should be more specially managed by a local governing institution.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.28-38
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• 2024

In this study, in order to analyze the water purification efficiency according to the influent water conditions of artificial wetlands, the purification efficiency was compared at two points where sewage treatment water flows in and one point where good effluent flows in. As a result of reviewing the results of the analysis of influent and effluent and the removal efficiency, the T-N and T-P removal efficiency was calculated at 54.7% and 77.4%, respectively, for the two points where sewage treatment water was treated, the treatment efficiency of SS 90.8%, BOD 51.1%, TOC 30.6%, T-N 38.8%, T-P 55.3% was shown. As a result, the efficiency of removing pollutants in the artificial wetland was found to be proportional to the concentration of influent water, and in order to create an efficient artificial wetland, it is judged that thorough review and management at the design stage are necessary considering that the removal efficiency of high-concentration contaminated water was high.