임연택 Im Yeon Taeg

DOI: Vol.19(No.4) 2-2, 2003

김동하 Kim Dong Ha , 김경진 Kim Gyeong Jin , 유환모 Yu Hwan Mo , 박선영 Park Seon Yeong

DOI: Vol.19(No.4) 349-356, 2003

In this research, we investigated the possibility of applying biosorption reaction to the advanced wastewater system with the analysis of the various operating conditions using the contact stabilization system. Biosorption is common reaction that makes biological removal, adsorption and coagulation achieved using the MLSS in the endogenous respiration. In the paper, we researched the influence of operating conditions, such as MLSS. adsorption time, DO, and activity of microorganism etc. in the biosorption reaction. And it was calculated the mass-balance lor the quantity analysis. The results were abtained as follows: 1. The optimal biosorption condition were determined adsorption time 15min, MLSS 2200㎎/L. DO 0.2㎎/L. Under this optimal condition, the carbon adsorption ratio was 65.5% and the total removal ratio was 81%. 2. The T-N. T-P adsorption ratio is 25.3%, 50.8% respectively under the optimal biosorption condition 3. The adsorption velocity is expressed as the Freundlich isotherm : COD_(ad)/MLSS=19.44(COD_(ex))^(0537). 4. In the optimal biosorption condition, the BOD_(5) amounts are 12.5g/day, which are able to remove the 3.7gNO₃-N/day.

Biosorption, adsorption ratio, coagulation, endogenous respiration

김성철 Kim Seong Cheol , 박청길 Park Cheong Gil , 조현서 Jo Hyeon Seo , 이대인 Lee Dae In

DOI: Vol.19(No.4) 357-366, 2003

Nonylphenol(NP) and Bisphenol A(BPA) are endocrine disruptors causing estrogenic effect and genital trouble etc This study was carried out to survey the characteristics of NP and BPA distribution in the surface sediments of Nakdong river. Concentration of NP and BPA ranged ND-25,144 and ND-57ng/g-dry wt in October, ND-56,696 and ND-84ng/g-dry wt in January, and ND-49.569 and 1 -48ng/g-dry wt in March respectively Results of grain size analysis, gravel was dominated at the upper reaches, sand at the middle reaches and mud in the river estuary dyke Maximum values of NP and BPA were found at river estuary dyke that sediment was composed of mud nearly and organic matters and metals was severely contaminated High levels of nomalized NP and BPA by mud showed at industrial complex nearby the Kumho river that was greatly affected sewage and wastewater NP and BPA concentration of this study area were relatively high in comparison with the other sites, it is necessary to control of noxious materials input to the water environment for water quality management

Nonylphenol, Bisphenol A, Nakdong River, Grain Size, Water Quality Management

유혜진 Yu Hye Jin , 박석순 Park Seog Sun

DOI: Vol.19(No.4) 367-375, 2003

The GWLF (Generalized Watershed Loading Functions) model was applied to the Kyungan stream watershed to estimate monthly nutrient loads. Based on the model structure, the Kyungan stream watershed was divided into 360 grid cells. Each cell had the size of 1,200×1,200 m. The model input parameters were obtained from Digital Elevation Model, Landsat TM imagery, soil map, and published literature on the study area. The model predictions were compared with the field measurements in stream flow as well as in nutrient loads. In most cases, there were reasonable agreements between measurements and predictions, where the coefficients of determination for stream flow, TN, and TP were 0.90, 0.83, and 0 73, respectively. The validated model was used to analyze the seasonal contributions of nutrients according to the types of sources. It was estimated that 7% of TN loads would originate from point sources, 49% from non-point sources and 44% from ground water during rainy season(August), while loads from non-point sources and ground water would be very low during dry season. 46 % of the total annual TN loads was from ground water, 30 % from point sources and 24 % from non-point sources. For land use loads, 14% of total loads were from dry field, 4% from paddy field, 3% from forest and 1% from residential. The contributions of TP loads were more than 90% for non-point sources in August, rainy season, while that of TP loads from non-point sources is very low in dry season. Of the total loads, loads from point sources were 44% and loads from non-point sources were 56% in the annual TP loads. For land use loads, 35% of total loads were from dry field, 11% from paddy field, 7% from forest and 4% from residential. Because nutrients from non-point sources are loaded in rainy season concentrically, appropriate action should be taken for this. In TN loads, contribution of loads from ground water was estimated very high. The results of GWLF model showed reasonable agreement with observed TN, TP loads in Kyungan stream watershed. In summary the GWLF model can be used to quantity non-point source loads effectively.

Seasonal load, GWLF model, Kyungan stream, Non-point source, Runoff flow, Nutrients

염철민 Yeom Cheol Min , 조순행 Jo Sun Haeng , 정현미 Jeong Hyeon Mi , 손진식 Son Jin Sig , 박수영 Park Su Yeong , 윤제용 Yun Je Yong

DOI: Vol.19(No.4) 377-384, 2003

The removal behavior of indicating microorganisms, such as HPC (Heterotrophic Plate Counts) and Bacillus subtilis endospore in water treatment process was investigated. Jar and column test were chosen to simulate flocculation/sedimentation. filtration process, and disinfection individually. The 1.7-1.8 log removal of HPC was achieved in flocculation/sedimentation. And 2.5 -2.6 log and 2.8-2.9 log total removal of HPC was reached by combined process of sand filter and dual media filtration process. This result indicates that a good flocculation/sedimentation process is important to acquire a high level of removal of indicating microorganisms. This tendency may be more important for protozoa removal such as Giardia and Cryptosporidium which is much larger in size. In addition, the flocculation/sedimentation/filtration process contributed to the 35 % reduction of CT values required for achieving the inactivation of 2-109 Bacillus subtilis under the same chlorine exposure environment.

HPC, Heterotrophic Plate Counts, Bacillus subtilis, flocculation, sedimentation, filtration

이순홍 Lee Sun Hong , 박종철 Park Jong Cheol

DOI: Vol.19(No.4) 385-392, 2003

In order to enhance the adsorption capacity of harmful heavy metal ions such as Cr(Ⅵ), Cu(Ⅱ), Pb(Ⅱ) and Fe(Ⅱ) from aqueous solution, the modified activated carbon(MAC) was made through the processes of ultrasonic and stirring treatment to increase the contact probability between the activated carbon and chitosan-acid solutions(1wt%-acrylic acid, acetic acid). Chitosan with high molecular weight-acid solutions was used as a coupling solution for existing many chemical adsorption sites onto the activated carbon exterior Surface and micropore, Specific surface area, micropore distribution and micropore diameter of MAC and pure activated carbon were very similar each other by BET measurement. These results suggest that the pore blocking phenomenon hardly occur during the modillcallon processes wth chitosan-acid solution. The amount of removed Cr (Ⅵ) by MAC was mostly higher than that 01 pure activatea carbon independently of pH. adsorption time and dosage at the same conditions. Regardless of the composition of heavy metal ions in the aqueous solution. the adsorption capacity of MAC for heavy metal ions was in the order of Cr (Ⅵ) > Fe(Ⅱ) > Cu(Ⅱ) > Pb(Ⅱ). Therefore. Cr(Ⅵ) can be preferentially removed in the wastewater containing Cr(Ⅵ) and other heavy metal ions

modified activated carbon, chitosan, heavy metal ions, ultrasonic and stirring treatment, chitosan-acid solutions, coupling solution

김용구 Kim Yong Gu , 박성천 Park Seong Cheon , 표영평 Pyo Yeong Pyeong

DOI: Vol.19(No.4) 393-400, 2003

Environmental pollution caused by population increase and industrial development influences river ecosystem. In order to conserve the water quality of the Tamjin river, it is necessary to estimate the BOD reduction rate. The BOD concentration is estimated by QUAL2E model applying in the target year 2007. The study basin of the Tamjin river is divided into 52 elements of 5 reaches. A target reduction rate of the BOD pollutant load which is satisfied mth target water quality in 2007 is predicted. A formula for calculating water quality management using regression analysis based on the various BOD reduction rates of the target basin is suggested.

QUAL2E, BOD reduction rate, Regression analysis

이웅 Lee Ung , 이성재 Lee Seong Jae , 박규홍 Park Gyu Hong , 배범한 Bae Beom Han , 장윤영 Jang Yun Yeong , 장윤석 Jang Yun Seog

DOI: Vol.19(No.4) 401-414, 2003

The objective of this research was to investigate the role of steelers` dust as a catalytic reagent in H₂O₂/steelers` dust system. In acidic condition, FeO and Fe₂O₃ in steelers` dust could be dissociated to produce ferrous ion and ferric ion, which reacted with hydrogen peroxide to produce hydroxyl radicals and then degrade 4-chlorophenol. The batch experiments showed that 0.51 5mM 4-chlorophenol and its oxidation intermediates could be totally decomposed within 60 minutes by 1g/L steelers` dust and 0.485mM hydrogen peroxide at pH 2.7. The removal of 4-chlorophenol in H₂O₂/steelers` dust system was affected by the concentration of hydrogen peroxide rather than the dose of steelers` dust. The rate constants in the simplified kinetic model proposed in this study were estimated by fitting to the experimental data obtained in H₂O₂/steelers` dust system. Using the estimated kinetic rate constants, the simulation of 4-chlorophenol, ferrous iron, hydrogen peroxide, and hydroxyl radical concentration was performed. The predicted concentrations of 4-chlorophenol and hydrogen peroxide corresponded to the actual concentrations. The concentration of ferrous iron tended to be underestimated while that of hydroxyl radical was overestimated by the proposed model. For the experimental conditions conducted in this study, a value of 0.3mM hydroxyl radical could be suggested to calibrate the overestimated prediction.

H2O2/steelers` dust system, 4-chlorophenol, Hydroxyl radical, Kinetics

손대희 Son Dae Hui , 정윤철 Jeong Yun Cheol , 유명진 Yu Myeong Jin

DOI: Vol.19(No.4) 415-424, 2003

Continuous experiments in laboratory scale SBBR(Sequencing batch biofilm reactor) with granular natural zeolites were conducted to investigate the effect of ammonium removal and regeneration by ion-exchange and nitrification. The proposed process used the ion exchange material as the media for the nitrifying and denitrifying biomass. The entire process was carried out in a single reactor. The SBBR type of three reactors were prepared for comparison of removal of nitrogen, organics and phosphorus. The first (modified Zeo-SBBR) and the second(Zeo-SBBR) reactors were filled with granular zeolite, and the third(A.C-SBBR) with granular activated carbon. Modified Zeo-SBBR and A.C.-SBBR were operated in new mode ; fill, mix, drain, backwash, and aeration, and Zeo-SBBR in conventional mode ; fill, mix aeration, backwash, and drain. The synthetic wastewater having 200㎎/L of NH₄^(+) was tested in this process. Results of this experiment were that modified zeo-SBBR showed the highest nitrogen removal efficiency. Total nitrogen removal efficiency showed 94%(modified zeo-SBBR), 75% (zeo-SBBR) and 79% (A.C-SBBR) respectively. In the case of modified zeo-SBBR, nitrogen removal was effectively enhanced by ion-exchange of the zeolite. And the zeolite saturated by ammonium was continuously regenerated by nitrification without a regeneration chemical such as NaCl. The results support that the proposed nitrogen removal process is very effective for treating ammonium bearing wastewater.

zeolite, modified zeo-SBBR, nitrification, denitrification, regeneration

황병기 Hwang Byeong Gi , 김경원 Kim Gyeong Won

DOI: Vol.19(No.4) 425-436, 2003

In this study, we perlormed 8 times of water quality sampling surveys and conducted continuous measurement of flows to identify wastewater flow characteristics for wastewater treatment basins of Guri city. The field survey has been conducted 6 times in dry weather period and 2 times in wet weather period. Each survey conducted 24-hr water quality sampling in the interval of 2-hr. Using automatic flowmeter. we obtained wastewater flow record in the interval of 10 minutes for more than MI days. From the analysis of flow data and water quality data the following conclusions can be drawn. Flow of Guri-1 station. which represents residential and commercial mixed area, rises early in the morning before office-going hour and moves UP and down within narrow range. and lasted alter office-leaving hour, resulting from continuous commercial activity. In contrast, Guri-3 station representing community and Guri-4 station representing residential area, the flow immediately falls down after rising early in the morning and later rises again at the olfice-leaving hour, and arrives at peak llows around late evening . In the analysis of wastewater characteristics for weekdays and weekends, without landuse types the flow rate of weekends is higher than that of weekdays because it rellects population being not contributed to generate wastewater during the working hours of weekdays stay home and produce wastewater for weekends period.

Guri, water quality sampling, flow measurement, landuse types, wastewater

김이태 Kim I Tae , 서재승 Seo Jae Seung , 이동률 Lee Dong Lyul

DOI: Vol.19(No.4) 437-444, 2003

Although the urban water demand per capita per day (lpcd) had an increased trend Until mid-l990s, since then it has become reducer and stable In this paper, the urban water demand divided into domestic water and others. which is business, commercial. public bath, and industrial water demand in city This paper evaluates the characteristics of urban water demand use and trend, and forecasts long-term demand considering the recent character with two exponential models Modified exponential model (Model 1) and least square method exponential model (Model 2) applied to the whole country and five cities The results of two models show that urban water demand is predicted to approach to stable level in 2011 year The forecasting of domestic water demand gives better results compared with that of other water demand in evaluation to mean absolute percentage error of both models

Water supply per capita per day, Modified exponential trend model, Least square method model, Domestic water use. Other water use

홍재용 Hong Jae Yong , 신응배 Sin Eung Bae , 김연권 Kim Yeon Gwon , 김백중 Kim Baeg Jung

DOI: Vol.19(No.4) 445-454, 2003

Recently, in order to meet the Strengthened effluent standard retrofitting the conventional activated sludge process into the advanced treatment process is on the increase, and the changes in microbial biomass fractions within the corresponding process largely affect the effluent water quality. depending on the operational condition. In this study, in order to evaluate the Changes in microbial fractions within the process, depending on the process change. weekly monitoring and respirometric method performed. As results from observing profile changes. the acclimation towards corresponding process and substrate was completed after about 4-5 weeks of adaptation period. The biomass fractions of heterotrophs and autotrophs for activated sludge and BNR process sludge changed from 19.0-21.8 to 15.8-16.1% and from 0.8-1.0 to 7.6-8.8% in VSS. respectively. Based on these results, it was concluded that the Changes in characteristics of activated Sludge process and advanced treatment process, depending on the microbial acclimation, can be better explained.

Retrofit, OUR, BNR, Active biomass fraction

이용두 Lee Yong Du , 현승규 Hyeon Seung Gyu , 송희경 Song Hui Gyeong

DOI: Vol.19(No.4) 455-461, 2003

The purpose of this study was to identify nitrate pollution level and Sources in groundwater at the watershed of Ongpo stream. For this study, two springs(S1 and S2) and 8 wells(W1 - W8) were Selected and investigation was accomplished from April to October, 2001 In using nitrate-nitrogen concentration and stable N isotopes. five sampling sites(S1, S2. W1, W2 and W5) were affected by livestock manure or sewage, but temporarily affected by chemical fertiiizer. Effects of livestock manure or sewage and chemical fertilizer for W3 and W4 were similar but they were affected by chemical Fertilizer in temporal.

nitrate, nitrogen isotope, groundwater, chemical fertilizer, livestock manure, sewage

학회자료

DOI: Vol.19(No.4) 463-464, 2003