정팔진 Paul Gene Chung , 조선영 Seon Yeong Jo , 현미희 Mi Hee Hyun , 김민정 Min Jeong Kim , 이은주 Eun Ju Lee , 전민식 Min Sik Jeon

DOI: Vol.20(No.6) 547-554, 2004

We found that the Bacterium Burkholderia cepacia in livestock wastewater treatment plant was predominant species. We investigated the growth rate of this and treatment characteristics for organic matter and nitrogen removal in livestock wastewater using this microorganism. First, we cultured B. cepacia. And then, to conducted treatment for livestock wastewater by using B. cepacia., we changed C/N from 0.2~4.4. When we operated A and B process, changing F/M ratio from 1.2 to 4.4. In experiment of C/N variations, when C/N was 1.8, we found that the optimal condition for organic matter and nutrient removal effect was higher and the removal efficiency of SCOD_(cr), SBOD_5, NH₄-N was 78.4%, 95% and 74.8%. So, It is possible to treat the wastewater having the lower C/N contents such as livestock wastewater using this microorganism. In experiment of A and B process for livestock wastewater, we found that the removal efficiency of organic matter and nitrogen in operating mode of A process was higher than that of B process. Also, the optimal F/M operating A process was 0.013 and the removal efficiency of SBOD_5, SCOD_(cr), TN and TP were 97%, 60%, 95% and 91%.

Livestock wastewater, Denitrification, Burkholderia cepacia, C/N ratio

한혜진 Hae Jin Han , 박석순 Seok Soon Park

DOI: Vol.20(No.6) 555-562, 2004

This paper presents the development and application of a riparian buffer zone design model(RBZDM). The model was developed as a decision-making tool for watershed management, by integrating geographic information system(GIS) and analytical hierarchy process(AFIP) theory. Several factors for watershed management, such as pollution removal capacity, land aquisition cost, distribution of point and non-point pollution sources, and possibility of new pollution source location, were analyzed based on AHP theory. The vegetated buffer zone width was designed using GIS-based riparian buffer analysis. The developed model was applied to the Kyoungan Stream watershed, which is an important part of Paldang lake catchment area. The Kyoungan stream watershed was divided into sixteen subbasins. Six of them belong to the main stem, where the model was applied. Ten alternatives of buffer zone width and five hierarchial levels were designed. The relative importance and the relative preference were computed by pair-wise comparison of evaluation criteria given in hierarchial levels. The buffer zone width was determined by linear function of the given alternatives and relative preferences. From this study, it was determined that the six buffer zone widths of Kyoungan main stems would be 1,594, 1,744, 1,856, 1,782, 1,338, 1,780 meter, from upstream to downstream.

Riparian buffer zone model, Watershed management, Analytical hierarchial process, Geographical information system, Kyoungan stream watershed

홍기호 Ki Ho Hong , 장덕 Duk Chang , 한상배 Sang Bae Han

DOI: Vol.20(No.6) 563-570, 2004

Phased isolation intrachannel clarifier ditch process developed in this study is an enhanced biological nutrient removal process employing two ditches with intrachannel clarifiers. Bench-scale phased isolation ditch process was used to evaluate the system performance on municipal wastewater and detailed assessment of internal behavior in a ditch and each reactions. When the system was operated at the HRTs of 6∼12hours, SRTs of 9∼31 days, and cycle times of 4hours, the system showed removals of BOD, TN, and TP as high as 88∼97%, 73∼78%, and 65∼90%, respectively. The internal behavior were well matched on each reactions such as nitrification, denitrification, and phosphorus release and uptake. As the SRT became longer, TN removal increased gradually, whereas TP removal decreased contrarily. However, the system was capable of producing an effluent TP concentration 1㎎/L or less even at longer SRTs except the case of solids discharge by malfunction of intra-clarifier occurred by its geometrical limit. The system performance slightly decreased by hydraulic shock loading(increasing of influent flowrate and decreasing of system HRT). However, the higher system performance could be achieved again after four cycles. Thus, the system reliability could be successfully achieved short-term hydraulic shock loading that occurred in medium- and small-sized wastewater treatment plants suffering fluctuation of influent quality and flowrate during wet season.

Biological nutrient removal, Municipal wastewater treatment, Oxidation ditch, Temporal phase separation, Phased isolation ditch process

김이태 I Tae Kim , 이희자 Hee Ja Lee , 김광수 Kwang Soo Kim , 배우근 Woo Keun Bae

DOI: Vol.20(No.6) 571-576, 2004

Since anaerobic/anoxic/oxic process, which is a typical mainstream biological nitrogen and phosphorus removal process, utilizes influent organic matter as an external carbon source for phosphorus release in anaerobic or anoxic stage, influent COD/T-P ratio gives a strong influence on performance of phosphorus removal process. In this study, a bench scale experiment was carried out for SBR process to investigate nitrogen and phosphorus removal at various influent COD/T-P ratio and nitrate loadings of 23∼73 and 1.6∼14.3 g NO₃-N/㎏ MLSS, respectively. The phosphorus release and excess uptake in anoxic condition were very active at influent COD/T-P ratios of 44 and 73. However, its release and uptake was not obviously observed at COD/T-P ratio of 23. Consequently, phosphorus removal efficiency was decreased. In addition, the phosphorus release and uptake rate in anoxic condition increased as the nitrate loading decreased. Specific denitrification rate had significantly high correlation with organic materials and nitrate loadings of the anoxic phase too. The rate of phosphorus release and uptake in the anoxic condition were 0.08∼0.94 ㎏ S-P/㎏ MLSS·d and 0.012∼0.1 ㎏ S-P/㎏ MLSS·d, respectively.

SBR, sequencing batch reactor, Phosphorus release and uptake, Denitrification, Anoxic condition, F/M ratio

박재홍 Jae Hong Park , 안상우 Sang Woo An , 장순웅 Soon Woong Chang

DOI: Vol.20(No.6) 577-582, 2004

The photocatalytic degradation of atrazine and PCP, a endocrine disruptors, has been investigated over TiO₂ photocatalysts under ultraviolet (UV) light irradiation. The effect of operational parameters, i.e., pH, light intensity and persulphate concentration on the degradation rate of aqueous solution of atrazine and PCP has been examined. The results presented in this work demonstrate that, as pH and the light intensity increased, the photocatalytic reaction rates were enhanced. Individual use of TiO₂-persulphate was far more effective than using only TiO₂ in atrazine and PCP removal. Based on the overall experimental results, the photocatalytic oxidation of atrazine and PCP with the coated TiO₂ photocatalyst is found to be very effective under the operational conditions delineated in this study.

TiO2, Atrazine, PCP, Persulphate

원철희 Chul Hee Won , 김병욱 Byoung Ug Kim , 한동준 Dong Joon Han , 임재명 Jay Myoung Rim

DOI: Vol.20(No.6) 583-588, 2004

This research examined the treatment efficiency and methane production rate in treating slurry-type swine waste using UASB (upflow anaerobic sludge blanket) reactor. The UASB reactor was operated at an organics volumetric loading rate (VLR) of 2.6-15.7 ㎏COD/㎥/day. A stepwise increase of the VLR resulted in a temporary deterioration in the COD removal rate in UASB reactor but recovered quickly. The COD removal rate were 65-70% for VLR up to 5 ㎏COD/㎥/day. When organics VLR was 10 ㎏COD/㎥/day, the COD removal rate decreased sharply and there was loss of 17.537g of the seeding biomass due to sludge washout. This result indicated that the UASB system cannot be adapted to more than 10 ㎏COD/㎥/day of VLR. As the organic load increased from 2.6 to 15.7 ㎏ COD/㎥/d, the biogas production rate varied from 3.2 to 10.8 L/d and the methane conversion rate of the organic matter varied from 0.30 to 0.23 ㎥CH₄/㎏ COD_(removed). The methane content showed the range of 70.1-81.5% during the experimental period. The volatile solids (VS) removal efficiency was similar at the low VLR (＜ 5 ㎏COD/㎥/day), but it decreased sharply at the high VLR (> 5 ㎏COD/㎥/day). The VS reduction rate was, moreover, large those of COD. The result shows that hydraulic retention time above 2 days is essential in case of treating wastewater containing 1% of solids.

Slurry-type swine waste, UASB, Methane conversion rate

김미아 Mi Ah Kim , 김영희 Young Hee Kim , 이홍근 Hong Keun Lee , 황대호 Dae Ho Hwang , 김지영 Ji Young Kim

DOI: Vol.20(No.6) 589-596, 2004

In this study, the reduction rates of nutrients were suggested to prevent eutrophication on the Hwaong reservoir in the year of 2008 and 2012. With EPA`s WASP6 model, future water quality were simulated. In 2008, T-N would be 1.36mg/L and T-P 0.100mg/L on average. ; In 2012, T-N 2.66mg/L and T-P 0.128mg/L. With all the water quality management plans that the government authorities are carrying out, these results indicate that the reservoir would be reach the eutrophic or hypertrophic state according to the Vollenweider`s trophic states. Therefore, the Hwaong reservoir requires additional plans for nutrients management. Here, the target water quality to prevent eutrophication of the reservoir sets into mesotrophic state ; T-N 0.475mg/L and T-P 0.02mg/L.(median of Vollenweider index for mesotropphic state) The reduction rates of nutrients on Namyang and Eoeun streams were estimated with uniform treatment method to meet the goal. The results showed that nutrients from two streams should be reduced up to 78% in 2008, and 84% in 2012. Since the ratio of T-N/T-P would be higher than 16 at target years, T-N was not considered as the limiting factor and was not reduced.

WASP6, Reliability index, Eutrophication, Nutrients, the Hwaong reservoir

황하선 Ha Sun Hwang , 공동수 Dong Soo Kong , 신동석 Dong Suk Shin , 전지홍 Ji Hong Jeon

DOI: Vol.20(No.6) 597-602, 2004

Field experimental study was performed to examine characteristics of nutrient export from paddy rice fields with irrigation practices. Experimental fields with surface-water and ground-water irrigation were monitored and analyzed during rice culture period. The water balance showed that outflow generally balanced the inflow showing that about half (58∼68%) of total outflow was lost by surface drainage. Water and nutrient export are more in surface-water irrigation paddy than in ground-water irrigation paddy. The reasons might be more irrigation water available and easy to use in surface-water irrigation. If irrigation water reduced, it could result in reduction of nutrient export in paddy rice fields, which can save water and protect water quality. However, deviation from conventional standard practices might affect the rice yield and further investigations are necessary.

Paddy field, Surface-water irrigation, Ground-water irrigation, Nutrient export, Water balance

황규대 Gye Dae Whang , 이봉희 Bong Hee Lee , 이현덕 Hyun Duk Lee

DOI: Vol.20(No.6) 603-609, 2004

The objective of this study was to determine the optimal operation conditions in an anoxic·oxic process to eliminate both organic and nitrogen matters in swine wastewater. For the purpose of this, the removal efficiency was evaluated with various HRTs and internal recycling ratio. During the whole 580 days of experiment, HRTs had been gradually decreased in an order of 20, 14, 12 and l0days, and the internal recycle ratio was kept at 20Q. So as to determine the effect of the internal recycle ratio on the nitrogen removal, the internal recycle ratio had been gradually increased from 20Q to 50Q while HRT was maintained at 12days. As a result, it was shown that the removal efficiency of organic matter was above 95% regardless of changing of HRTs. The average influent concentration of TCODcr and SCODcr were 24,854 ㎎/L and 18,920 ㎎/L, respectively. Average removal efficiency of TKN was shown to be nearly 98% when HRT was kept at 12days; however, the NH₄^+-N concentration of effluent was shown to be increased when the loading rate of NH₄^+-N was increased to 0.602 kgNH₄^+-N/m³-day by means of decreasing HRT to 10days. It was concluded that nitrogen loading rates should be more considered rather than organic loading rates in case of determining an optimal HRT. When gradually increasing the internal recycle ratio from 20Q to 50Q, the removal efficiency of organic matters and TKN were 96% and 98%, respectively so that no significant changes in removal efficiency was detected. However, when the internal recycle ratio was kept at 50Q, it was revealed that the NO₃-N concentration of effluent seemed to drop and the average NO₃-N concentration of effluent was around 52 ㎎/L.

Anoxic,oxic process, HRT, Internal recycle ratio

조창우 Chang Woo Cho , 유재웅 Jae Woong Ryou , 정팔진 Paul Gene Chung

DOI: Vol.20(No.6) 610-614, 2004

The objective of this study was to remove organics and color in livestock wastewater using coagulation and Fenton oxidation process. After coagulation process as 1^(st) treatment, organics in 1^(st) treatment water were removed by using OH radical produced in Fenton oxidation process. Removal efficiencies of COD_(Mn) and color were 87.2% and 95.7% separately. At that time, the ratio of Fe^(2+)/ H₂O₂ was 0.8∼1.0, and range of reaction pH was effective at the pH of 3.5∼3.8. The Reaction time of 120min more than 60min or 90min was sufficient in Fenton process. Removal efficiency of organics was higher two- or multi-stage treatment than one-stage treatment.

OH radical, Coagulation, Fenton oxidation process, Livestock wastewater

박혜경 H. K. Park , 변명섭 M. S. Byeon , 김은경 E. K. Kim , 이현주 H. J. Lee , 전명진 M. J. Chun , 정동일 D. I. Jung

DOI: Vol.20(No.6) 615-624, 2004

The distribution pattern of water quality parameters and phytoplankton biomass in upper inflow rivers of lake Paldang had surveyed. In North-Han river system, nutrient concentrations and algal biomass was below the standard of mesoand oligotrophy from lake Soyang to lake Paldang, maintaining good water quality, except the N5 site located near the Chuncheon-Si, showing high nutrients concentrations and algal biomass. The algal biomass of the South-Han river system showed oligotrophic level in the upstream near the lake Chungju, and increased along the flow direction showing eutrophic level in the downstream within the lake Paldang area. On the other hand, the highest concentrations of nutrients were detected in the middle stream near the Yeoju-Si and Yangpyung-Gun rather than in the downstream suggesting algal biomass in lake Paldang would not come from the upper river area but come from the growth within the lake area using nutrients from the upper inflow river.

Lake Paldang, Upper inflow rivers, North-Han river, South-Han river

김진근 Jin Keun Kim

DOI: Vol.20(No.6) 625-630, 2004

Granular media filtration is used almost universally as the last particle removal process in conventional water treatment plants. Therefore, superb particle removal efficiency is needed during this process to ensure a high quality of drinking water. However, every particle can not be removed during granular media filtration. Besides the pattern of particle attachment is different depending on physicochemical aspects of particles and suspension. Filtration experiments were performed in a laboratory-scale filter using spherical glass beads with a diameter of 0.55 mm as collectors. A single type of particle suspension (Min-U-Sil 5) and alum coagulation was used to destabilize particles. The operating conditions were similar to those of standard media filtration practice: a filtration velocity of 5 rn/h. More favorable particles, i.e., particles with smaller surface charge, were well attached to the collectors especially during the early stage of filtration when zeta potential of particles and collectors are both negative. This selective attachment of the lower charged particles caused the zeta potential distribution (ZPD) of the effluent to move to a more negative range. On the other hand, the ZPDs of the effluent moved from more positive to less positive when the surface charge of particles was positive and this result was thought to be caused by ion transfer between particles and collectors.

Filtration, Particle attachment, Destabilization, Zeta potential distribution, 여과, 입자물질부착, 불안정화, 제타전위분포

김이형 Lee Hyung Kim , 강주현 Joo Hyon Kang

DOI: Vol.20(No.6) 631-640, 2004

This research was conducted to understand the magnitude and nature of the stormwater emissions with the goal of quantifying stormwater pollutant concentrations and mass emission rates of pollutants. Eight highway sites in Southern California area were monitored for three years with collecting of grab and flow-weighted composite samples, rainfall and runoff flow. Generally the EMCs cannot be determined by simple statistical averaging of measured pollutant concentrations because of random characteristics of runoff quality and quantity. Therefore, this manuscripts will show a new EMC determination method. The EMC ranges of 95% confidence intervals are 102.78-216.37㎎/L for TSS, 104.53-251.79㎎/L for COD, 5.42-10.58㎎/L for oil & grease and 2.42-10.18㎎/L for TKN. The ranges of washed-off mass loading are determined to 0.06g/㎡-17.27g/㎡ for TSS and 0.1-3.23g/㎡ for COD.

EMC, Highway, Los Angeles, Nonpoint pollutant, Washoff

김이형 Lee Hyung Kim , 강주현 Joo Hyon Kang

DOI: Vol.20(No.6) 641-646, 2004

Vehicle emissions from highway landuse include different pollutants such as heavy metals, oil and grease and particulates from fuels, brake pad wear and tire wear. Since highways are impervious and have high pollutant mass emissions from vehicular activity, it is considered as stormwater intensive landuses. Therefore this research was performed to understand the magnitude of first flush and to suggest the criteria of first flush for storm runoff management in highways. The fractions of washed-off mass are very high in first 30% of runoff volume, which suggests a definition of first flush. The washed-off mass stabilizes after 30% of the runoff volume and it is apparent that treatment capacity in the early part of a storm is more valuable than treatment capacity in the later part of the storm. Using the criteria of "high" first flush and "medium" first flush, as 50% of the mass in the first 30% of the volume, and 30 to 50% in the first 30% volume, respectively, more than 30% of the storms showed high first flush. A "first flush friendly" best management practice(BMP), meaning a BMP that can treat a high percentage or all of the initial flow, would be advantageous up to 80% of the events.

Best management practices, First flush, Highway, Los Angeles

임세호 Se Ho Lim , 고광백 Kwang Baik Ko , 오영기 Young Khee Oh

DOI: Vol.20(No.6) 647-651, 2004

In this study, some of bacterial growth kinetic parameters were delineated and evaluated for the biological nutrient removal processes such as the A²/O, 4stage-BNR, Intermittent Cycle Extended Aeration System(ICEAS) and Intermittently Aerated Cylindrical Oxidation Ditch(IACOD) processes. Y_H values for the ICEAS process ranged from 0.71 to 0.74, and were higher than those for the other processes. It seems to indicated that organic carbons uptaked by microorganism were more used up for cell synthesis rather than for energy components in the ICEAS process. b_H for the ICEAS and IACOD processes were lower than those for A²/O and 4stage-BNR processes. The μ_(max·A) for the ICEAS was higher than those for the other processes, which indicated that desirable operating conditions for nitrifying bacteria`s growth were established.

YH, bH, μmax, A(2)/O process, 4stage-BNR process, ICEAS process, IACOD process

정용준 Yong Jun Jung , 민경석 Kyung Sok Min

DOI: Vol.20(No.6) 652-656, 2004

Both surface wash and backwash are considered as one of the most important methods that can improve the filtration efficiency in the existing water treatment plant. This study has mainly focused on the improvement of filtering efficiency by controlling surface wash and backwash time, and water level before backwash (when drained up to the trough, when drained up to 10 cm above filter bed, and when drained below 10 cm filter bed). Filtration efficiency was shown a little bit of differences depending on the operating conditions like surface wash injection pressure, the distance control between filter bed and the facility, and the types of surface wash. When the water level before backwash was reached up to 10 cm below filter bed after draining, however, the filtration velocity and the turbidity removal efficiency in the filter bed was improved. When the surface wash followed by backwash is longer, it showed a similar result. Because the proper adjustment of surface washing time makes filtration efficiency higher, therefore, it is necessary to set up the backwash time moderately.

Surface wash, Backwash, Rapid sand filter, Water treatment, Filtration

오영택 Young Taek Oh , 박제철 Je Chul Park , 김동섭 Dong Sup Kim , 류재근 Jae Keun Rhyu

DOI: Vol.20(No.6) 657-663, 2004

The aims of this study are the characterization of runoff from nonpoint source, the analysis of the pollutant loads and an establishment of a management plan for nonpoint source of Okcheon. For this purpose the basin of the stream So-okcheon was selected to the investigated. During the period from May 29 to July 21 in 2003, the water automatic sampler system has been installed in Okkagkyo and parameters such as SS, COD, TOC, TP and TN were analyzed. The pollutants of nonpoint source seem to be washed out along the stream water in the beginning of rainfall, remain in water and cause the stream pollution. The runoffs during heavy rainfall, especially, much higher concentration of SS than those during dry period. With respect to the annual loading of pollutants of the nonpoint source, the COD was 124 ton/yr, TOC 396 ton/yr, TN 1,429 ton/yr and TP 4.2 ton/yr in the year 2002. With respect to the pollutants loading of the nonpoint source, the COD was 375 ton/yr(95% of the total COD loading of 394 ton/yr), TOC 844 ton/yr(96% of the tatal TOC loading of 876 ton/yr), TN 1,985 ton/yr(96% of the total TN loading of 2,062 ton/yr) and TP 37.1 ton/yr(92% of the total TP loading of 40.3 ton/yr) in the year 2003.

Nonpoint source, Pollutant loading, Okcheon, Rainfall, Runoff

정용준 Yong Jun Jung , 배종홍 Jong Hong Bae , 권구호 Koo Ho Kwon , 민경석 Kyung Sok Min

DOI: Vol.20(No.6) 664-669, 2004

An upflow BAF(Biological Aerated Filter) equipped with an expanded clay media was applied to reuse weaving wastewater of water jet loom. The performance of lab-scale biofilter was investigated by the adjustment of EBCTs(Empty Bed Contact Time) and the packing ratio of media, which were changed 1.1 to 3.7hr and 38 to 63%, respectively. In most conditions except 1.1hr of EBCT, BOD, CODcr, SS and Turbidity of the effluent were 1∼4㎎/L, 7∼16㎎/L, 1∼5㎎/L and 5∼14NTU, where their removal efficiencies were 76∼95%, 82∼93%, 63∼94% and 59∼81%, respectively. From the observation of SEM(Scanning Electron Microscope) photographs of porous clay media, it was revealed that this media provided good performance of retaining microbes effectively. In addition, 0.44∼0.49㎏VSS/㎏BOD_(rem). of low sludge reduction was expected. The most efficient back washing cycle and procedure were once per 4 to 9 days and air including collapse-pulsing method, respectively. Therefore, this system can be of use as an weaving wastewater treatment for reuse

BAF, Weaving wastewater, EBCT, Reuse

민지은 Jee Eun Min , 박재우 Jae Woo Park

DOI: Vol.20(No.6) 670-675, 2004

Humic acids are macromolecules originated from natural water, soil, and sediment. The characteristics of humic acid enable it to change the distribution of metals as well as many kinds of organic contaminants and to determine the sorption of them from soil solution. To see the effect of humic acid on the removal rate of organic contaminants and heavy metals, batch-scale experiments were performed. As a natural geosorbent, black shale was used as a sorbent media, which showed hight sorption capacity of trichloroethylene (TCE), lead, cadmium and chromium. The effect of sorption-desorption, pH, ionic strength and the concentration of humic acid was taken into consideration. TCE sorption capacity by black shale was compared to natural bentonite and hexadecyltrimethylammonium (HDTMA) modified bentonite. The removal rate was good and humic acid also sorbed onto black shale very well. The organic part of humic acid could effectively enhance the partition of TCE and it act as an electron donor to reduce Cr(Ⅵ) to Cr(Ⅲ). Cationic metal of Pb(Ⅱ) and Cd(Ⅱ) also removed from the water by black shale. With 3 mg/L of humic acid, both Pb(Ⅱ) and Cd(Ⅱ) were removed more than without humic acid. That could be explained by sorption and complexation with humic acid and that was possible when humic acid could change the hydrophobicity and solubility of heavy metals. Humic acid exhibited desorption-resistivity with black shale, which implied that black shale could be an alternative sorbent or material for remediation of organic contaminants and heavy metals.

Sorption, Humic acid, Black shale, Reduction, Trichloroethylene, Chromate, Lead, Cadmium

김성진 Seong Jin Kim , 곽동희 Dong Heui Kwak , 임영환 Young Hwan Lim

DOI: Vol.20(No.6) 676-684, 2004

Many researchers have been carrying on study to figure out the exact collision efficiency between bubble and floc. Collision efficiency can has generally been quantified by using trajectory analysis which uses the hydrodynamic, the electrostatic and van der waals forces. Two types of method are considered to induce the hydrodynamic force in the trajectory analysis. One is to use stream function and the other is to use mobility function. There was some difference between stream and mobility function depending upon modelling factors and conditions in trajectory analysis.

Dissolved-air flotation, Bubble, Flotation separation, Streamline, Trajectory analysis

김상단 Sang Dan Kim , 유철상 Chul Sang Yoo

DOI: Vol.20(No.6) 685-691, 2004

Water quality forecasting with long term flow is important for management and operation of river environment. However, it is difficult to set up and operate a physical model for water quality forecasting due to large uncertainty in the data required for model setting. Therefore, relatively simpler stochastic approaches are adopted for this problem. In this study we try several multivariate time series models such as ARMAX models for the possible substitute for water quality forecasting. Those models are applied to the BOD and COD levels at Noryangin station, Han river, and also evaluated the effect of release from Paldang dam on them. Monthly BOD and COD data from 1985 to 1991 (7 years) are used for model building and another two year data for model testing. As a result of the study, the effect of improvement on water quality is much more effective combining with the water quality improvement of dam release than considering only increment of dam release in the downstream Han river.

Water quality, Dam release, Stochastic model

신응배 Eung Bai Shin , 김미경 Mee Kyung Kim , 홍준혁 Jun Hyeok Hong , 공동수 Dong Soo Kong

DOI: Vol.20(No.6) 692-697, 2004

Biological phosphorus removal is characterized by complex interactions between different intracellular components of energy as PHA. Therefore, fundamental understanding of the behavior of the intracellular components and their influence on the removal of phosphorus is essential before control strategies to stabilize the proper process. The purpose of this study is to investigate relationship between release of phosphorus and synthesis of intracellular storage polymer. Mass of stored intracellular storage polymer was 21.2 ㎎ PHA/L, 28.8 ㎎ PHA / g MLSS. And phosphorus release/ intracellular storage polymer synthesis rate was 1.8545 ㎎ stored polymer/㎎ Phosphate. In the aerobic phase, mass of PAOs synthesis is 49.37 ㎎ PAOs/L. And PAOs fraction was 6.7-6.9%. Thus intracellular storage polymer synthesis by PAOs is calculated as 493㎎ PHA / g PAOs.

Enhanced biological phosphorus removal, PAO, Intracellular storage polymer, PHA

이동석 Dong Seok Yi , 박갑성 Kap Song Park

DOI: Vol.20(No.6) 698-702, 2004

At five stations in Gyeongan River, a tributary of Lake Paldang, physicochemical and biological environmental factors of water, particulate matters, and sediments were investigated biweekly from April 11 to December 22 in 2001. The studied area was characterized as a stream-lake system. The system is primarily referred to a place where the environmental factors had considerably changed depending on the amount of precipitation. As a result, the river turned out to be strongly eutrophicated. Also, some characteristics of the water and the particulate matters at midstream such as average concentrations of conductivity, nutrients, and chlorophyll α were higher than the characteristics of up and down-stream. However, the concentrations of organic matters and ratio of clay and silt of the midstream were determined to be higher than up and down-stream sediments. As the result of the factor analysis, 4 major different patterns for environmental factors are found from samples of water, particulate matters, and sediments.

Environmental factors, Eutrophication, Gyeongan River, Water, Particulate matters, Sediments

김상단 Sang Dan Kim , 송미영 Mee Yong Song , 이기영 Ki Young Lee , 이성룡 Seong Ryong Lee

DOI: Vol.20(No.6) 703-707, 2004

In this study, a simple regression model is proposed in order to analyse the effect of population and urban land use on the water quality of Paldang lake, Gyeonggi. As a comparison result with Qua12E water quality model, the proposed model shows very good predicting performance in simulating several alternative scenarios. In order to accomplish BOD 1ppm of Paldang lake, various model applications show that the population incoming and urban land use management should be afoot in addition to stricter outflow water quality from sewer treatmement systems.

Population, Urban land use, Qual2E

이은주 Eun Ju Lee , 정팔진 Paul Gene Chung , 김민정 Min Jeong Kim , 현미희 Mi Hee Hyun

DOI: Vol.20(No.6) 708-713, 2004

This study was performed to investigate the variations of hydrophilic and hydrophobic organic matter fractions in soluble organic matter according to livestock wastewater treatment by ionized gas and coagulation effect to these fractions after ionized gas contact. As a result of experiment, because of ionized gas contact, particle in the surface of livestock wastewater was more smaller and the result was consisted of particle size analysis and the amount of small size was increased. Also, we confirmed that organic matters in livestock wastewater by ionized gas contact were removed. The relation equation between ionized gas contact time(X) and TCOD_(cr)(Y) was shown as yscale(y)=3.748-0.431^*xscale(X). That between ionized gas contact time(X) and SCOD_(cr)(Y) was yscale(y)=3.283-0.463^* xscale(X). As respects the HPL(hydrophilic matter)and HPO(hydrophobic matter) fractions of raw in livestock wastewater treatment plant, HPL fraction was 53.2% and HPO fraction was 46.8%. But, HPO fraction according to ionized gas treatment was increased at 30min and after that time, HPL fraction was increased. Also, when we performed coagulation process after ionized gas treatment of raw wastewater, the removal efficiency of organic matter was the highest at 30min of ionized gas treatment because of the variation of HPL and HPO fractions in organic matter by ionized gas. In coagulation process following after ionized gas process, HPO was removed more effective than HPL.

Ionized gas, Livestock wastewater, Hydrophilic matter, Hydrophobic matter, Coagulation, Particle size, Organic matter