• Journal of Korean Society of Environmental Engineers
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• v.34 no.8
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• pp.549-556
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• 2012

T-P removal efficiency was analyzed according to the metal to initial T-P ratio (mole basis) with respect to the samples from different WWTPs having various initial T-P and SS conditions. Also, operating costs were calculated based on the injected coagulant amount and the amount of sludge production. Most experiments were conducted by the standard jar-test protocol. Molar ratio of coagulant dose was varied considerably according to the initial SS concentration range in secondary clarifier effluent samples which had above 0.5 mg/L of initial T-P. Based on 90% T-P removal efficiency, results were: At the initial SS range of below 10 mg/L, Alum (8%) = 11 mol Al/mol P needed and PAC (17%) = 9.6 mol Al/mol P needed; At the initial SS range of above 10 mg/L, Alum (8%) = 3.9 mol Al/mol P needed and PAC (17%) = 3.2 mol Al/mol P needed.

• Journal of Korea Soil Environment Society
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• v.4 no.2
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• pp.77-86
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• 1999

Partitioning of two hydrophobic organic compounds (HOCs), phenanthrene and naphthalene, to kaolinite and sorbed surfactants was studied to evaluate the feasibility of surfactant-enhanced remediation (SER) of contaminated subsurface systems. Sorbed surfactant partition coefficients. $K_ss$, showed a strong dependence on the surfactant sorption isotherms at low sorbed surfactant levels $K_ss$ values were at their highest and then decreased with increasing surfactant sorption densities. $K_ss$ values for SDS were always larger than corresponding $K_mic$values. For Tween 80, however. $K_ss$ values $K_mic$ were higher than $K_mic$ values only at the lower sorbed surfactant densities. HOC distribution between immobile and mobile phases varied with surfactant dose distribution coefficients increased initially with increasing surfactant concentrations and then decreased at higher doses. This observation shows directly the competition between sorbed and micellar surfactants for HOC partitioning. Overall results of this study demonstrate that surfactant sorption to the solid phase can lead to increases in HOC retardation in some SER applications. Therefore, before an SER process is selected, appropriate consideration of surfactant sorption and HOC partitioning to immobile versus mobile phases pertinent to a specific subsurface system must be contemplated.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.9-15
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• 2019

The Daegi-cheon watershed is located in the upper part of the Han River, which has the representative highland vegetable growing complexes. This watershed has a large impact on the water quality and aquatic ecosystem in the upstream of the Han River by discharging a large amount of turbid water during rainfall season. For proposing an efficient turbid water management and policy, the analysis of the characteristics of flow rate and SS and its causes needs to be carried out preferentially. In this study, the relationship between flow rate and SS concentration was analyzed in the Daegi-cheon watershed, and in turn the turbidity characteristics were analyzed. As a result of the study, in the normal flood flow condition, it was shown that SS concentration changed arbitrarily due to various environmental factors. On the other hand, the SS concentration was considerably high in the very high flow condition. Based on the field survey, this could be the reason why the effects of the steep valley and slope collapse according to the very high flow rate as well as the source in the agricultural fields were greatly contributed. Therefore, it is necessary to develop a structural best management practice that can stabilize the steep slope and reduce river bed loss along with the typical source managements plans.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.10
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• pp.685-690
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• 2014

The treatment of combined sewer overflow (CSO) is one of potential concerns in domestic wastewater treatment in Korea due to the pre-announce of CSO regulations. This work investigated the effects of disinfectant (NaOCl) concentration (0.11 to 4.0 mg $Cl_2/L$), pH (6.5 to 8.0), temperature (15 to $25^{\circ}C$), ammonia (10 to 41 mg N/L), and suspended solids (91 to 271 mg SS/L) on the chlorine disinfection of CSO. The effect of NaOCl concentration on the pseudo-$1^{st}$ order reaction rate for total coliform inactivation was described well with a saturation-type model with the half-velocity constant of 1.212 mg/L. The total coliform inactivation reaction rate decreased with SS and pH, and increased with temperature. Ammonia in the examined range did not affect the disinfection kinetics. A chlorine contact tank with the injection chlorine level of 1 mg $Cl_2/L$ and the hydraulic retention time of 1.25 min is estimated to reduce total coliform from $1{\times}10^5MPN/mL$ to 1,000 MPN/mL at 271 mg SS/L, $15^{\circ}C$, and pH 8.0. Chlorine would be a proper option for the disinfection of CSO.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.540-550
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• 2013

Temporal increase of SS induces concentrations in various forms of organic matter including BOD, COD, TOC. Consequently, it causes hard to identify sources of water pollution during or after precipitation. The objective of this study is to investigate variations of DOC concentration caused by increase of flow and changes of external factors in river by comparing to SS concentration. In results, monitoring sites (e.g., Banbyeonchen) consisting of hard riverbed showed high correlation between SS and organic matters, except BOD. On the contrary, other sites (e.g., Naesungcheon) where riverbed consists of sand were found in a wide range of annual fluctuation in SS level, whereas these sites showed a narrow range in annual DOC fluctuation. In Gumhogang and Namgang, a lower correlation between SS and other factors was found most likely because of high concentration in organic matter. However, lower annual fluctuation values of DOC were observed in comparison to those of COD and TOC. Similar results were also confirmed in main river sites, Sangju and Mulgeum. In conclusion, DOC concentration is better indicator for monitoring organic matter which cannot be provided by BOD, COD, TOC in the Nakdong river basin.

• The Korean Journal of Physiology
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• v.7 no.2
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• pp.9-16
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• 1973

In view of the recent knowledge on the radioprotective action of reduced glutathione (GSH), the present study was designed the elucidate the effect of some concentrations of GSH on the levels of intrinsic non-protein sulfhydryl (NP-SH) and non-protein disulfide (NP-SS) of the mouse liver incubated at 4, 25 and 37C in vitro, respectively. The liver slice of the mouse was incubated at 4, 25 and 37C in the medium composed of 100 ml of Krebs-Ringer phosphate buffer (KRP) with the addition of 10, 20 and 30 mg of GSH, respectively. Measurement of NP-SH and NP-SS was made at 5, 30 and 60 min during the course of the incubation, and the results were compared with the controls which were incubated only in KRP medium, and the normal. The results thus obtained are summarized as follows: 1. When the mouse liver slice was incubated at 4C, the values of both NP-SH and NP-SS of the control and the group where 10 mg of GSH was added to the incubation medium were similar to those of the normal group, and the increase of NP-SH and NP-SS with the increased concentrations of GSH was not prominent. 2. When the liver slice was incubated in the concentrations of GSH 20 mg/100 ml KRP and GSH 30 mg/100 ml KRP at 25 C, the rate of increase of both NP-SH and NP-SS was proportional to the increase of GSH concentration. In the group where 10 mg of GSH was added to the incubation medium, the value of NP-SH and NP-SS reached the highest value at 30 min, but a tendency of decrease was observed at 60 min. 3. The rate of increase of NP-SH and NP-SS of the liver was most marked of all the group. studied when the incubation temperatuse was elevated to 37C, and the increase was proportional to the concentration of GSH and the incubation time.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.3
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• pp.304-310
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• 2007

The purpose of this research was to investigate the effects of the co-treatment of municipal wastewater with microwave-irradiated excess sludge on the treatment efficiency and excess sludge production of the activated sludge process. When 250 mL of excess sludge with a MLSS concentration of approximately 2,000 mg/L was microwave-irradiated at $20^{\circ}C$ for $40\sim300$ sec by a microwave oven (2,450 MHz, 700 W), the temperature of the sludge increased at a rate of approximately $20^{\circ}C/min$ and the SCOD, TKN and T-P concentrations of the sludge showed the highest increase in the irradiation time of $40\sim130$ sec. And, the oxygen uptake rate measurement of the sludge microorganism suggested most of the microorganisms in the sludge were destroyed at an irradiation time above 130 sec(above $65^{\circ}C$). When the municipal wastewater and microwave-irradiated excess sludge was co-treated by the activated sludge process, almost no effect was observed in the pH and alkalinity of both the influent and effluent, but the influent concentrations of SS, COD, T-N and T-P increased. Even though the effluent SS, BOD and T-P concentrations showed almost no effect, the COD and TKN concentrations increased. The microbial yield coefficient decreased at a rate of 0.91 g SS/g COD removed as the irradiation ratio increased at a rate of 1 g SS/g SS-day.

• Journal of Korea Water Resources Association
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• v.30 no.6
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• pp.621-628
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• 1997

Excavation works on stream beds have been done for various reasons including aggregate collection, sediment dredging, bridge constructions, or laying pipes under the ground. These activities may cause significant loadings of SS (suspended solids) resulting in water pollution and other detrimental effects to the surrounding environment. This research investigates application potential of a fickian diffustion model, derived from two dimensional advection-diffusion equation through some simplifying assumptions, as a planning tool for the estimation of SS loadings from excavation works and evaluation fo pollution prevention measures in case that sophisticated numerical simulation models are not applicable due to various practical reasons. Through a case study of the Juncheon stream in the Donghae City on the Kangwondo Province, this study demonstrates applicability of the fickian diffustion model as a practical method for the preliminary estimation of Ss loadings from excavation works and evaluation of performance of fabrics made of synthetic fiber for the reduction of downstream SS concentration with deficient field data.

• Korean Journal of Remote Sensing
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• v.26 no.2
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• pp.189-207
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• 2010

Several ocean color algorithms have been developed for GOCI (Geostationary Ocean Color Imager) using in-situ bio-optical data sets. These data sets collected around the Korean Peninsula between 1998 and 2009 include chlorophyll-a concentration (Chl-a), suspended sediment concentration (SS), absorption coefficient of dissolved organic matter ($a_{dom}$), and remote sensing reflectance ($R_{rs}$) obtained from 1348 points. The GOCI Chl-a algorithm was developed using a 4-band remote sensing reflectance ratio that account for the influence of suspended sediment and dissolved organic matter. The GOCI Chl-a algorithm reproduced in-situ chlorophyll concentration better than the other algorithms. In the SeaWiFS images, this algorithm reduced an average error of 46 % in chlorophyll concentration retrieved by standard chlorophyll algorithms of SeaWiFS. For the GOCI SS algorithm, a single band was used (Ahn et al., 2001) instead of a band ratio that is commonly used in chlorophyll algorithms. The GOCI $a_{dom}$ algorithm was derived from the relationship between remote sensing reflectance band ratio ($R_{rs}(412)/R_{rs}(555)$) and $a_{dom}(\lambda)$). The GOCI Chl-a fluorescence and GOCI red tide algorithms were developed by Ahn and Shanmugam (2007) and Ahn and Shanmugam (2006), respectively. If the launch of GOCI in June 2010 is successful, then the developed algorithms will be analyzed in the GOCI CAL/VAL processes, and improved by incorporating more data sets of the ocean optical properties data that will be obtained from waters around the Korean Peninsula.

• Journal of the Korean Society for Marine Environment & Energy
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• v.20 no.2
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• pp.76-83
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• 2017

In order to investigate the characteristics of water quality and heavy metals in Shihwa Lake, concentration comparisons according to land use types and mass discharge through streams were carried out. Based on classification for streams according to land use types, the concentration of DO, SS, POC, $NO_3$ and Chl-a showed higher concentrations in agricultural areas than in industrial and urban areas. However, COD, DIN, DIP, TN, TP, DOC, TOC and heavy metal concentrations showed relatively high values in industrial areas. The concentrations of water qualities and heavy metals were relatively high in March to May and the concentration decreased in summer seasons (July-August). The averages of stream discharges of water qualities were 1,172 kg/d for SS, 151 kg/d for TN, 11.1 kg/d for TP and 389 kg/d for TOC, respectively. The agricultural area, Jangjunbo(S8), accounted for 47.5%(TP)~75.1%(SS) in the total stream discharges. Cu, Zn and Cd in stream waters were found to be more than 92% of the total discharges in industrial area, showing descending order of Zn>Cu>Ni>Pb>Co>Cd.