KNU-Tottori Exchange Symposium Proceeding

12th International Conference on Integrated Diffuse Pollution Management (IWA DIPCON 2008)

The Proceeding of

The 8th Joint Symposium ofKangwon National University and Tottori Universityon Environmental Science and Technology

October 10-13, 2010Kangwon National University Chuncheon, Korea

Chairman of Local Organizing Committee: Bomchul Kim

Organized by: Department of Environmental Science, Kangwon National University, KoreaDepartment of Social Systems Engineering, Tottori University, JapanInstitute of Environmental Research at Kangwon National University, KoreaResearch Institute for Basic Science at Kangwon National University, Korea

Program schedule

October 11, 2010 (Mon) 09:00~17:30

Opening Ceremony Professor Bomchul KIM (Kangwon National Univ.)

Oral Session (20 min each)

Session 1 09:10~10:10 - Plenary lecture Yoshihiko HOSOI (Tottori Univ. Prof.) : Water Quality Deterioration in Aging Drinking Water Supply Pipelines Satoshi AKAO (Tottori Univ. Prof.) : Fermentation of Lignocellulosic Biomass Derived Sugars to L-Lactate by Thermophilic Hiroshi YAJIMA (Tottori Univ. Prof.) : Relationship between Hydrodynamics and Removal Effect of Periphyton by Artificial Flood in the Hoo Stream (Korea)

Session 2 10:30~11:50 Ichiro WAKIMOTO (Tottori Univ.) : Planning of Efficient Garbage Collection System in Depopulation Areas Hyungjun LEE (Tottori Univ.) : Effect of Surface Condition of Paddy Fields on Pollutants Runoff during Non-irrigation Period Myoungsun SHIN (Kangwon National Univ.) : Long-term Variation of Water Quality in the Lower Han River Saeromi LEE (Kangwon National Univ.) : Total Dissolved Gas and Gas Bubble Disease

Lunch 12:00~13:30

Session 3 13:30~14:30 Jaesung EUM (Kangwon National Univ.) : Export of Phosphorus and Nitrogen from Agricultural River Basins in Korea Heewon NAM (Kangwon National Univ.) : The Analysis of the Effect of Land Use and Forest Physiognomy on the Stream WaterTatsuya KONDO (Tottori Univ.) : Estimation of Collection and Transport Costs of Septic Tank Sludge in Tottori PrefectureSession 4 15:00~16:00 Jungkyu CHOI (Tottori Univ.) : Effect of Clear Water bypass Operation on the Water Quality in a Reservoir Koutarou MAEDA (Tottori Univ.) : Pretreatments Affecting Enzymatic Saccharification and L-lactate Fermentation Misook PARK (Kangwon National Univ.) : Removal Effects of Periphyton by Artifitial Floods at the Downstream of a Dam (The Hoo Stream, Korea)Sunjung KIM (Kangwon National Univ.) : Real-time Water Quality Monitoring

Session 5 16:30~17:30 Yunkyoung LEE (Kangwon National Univ.) : Ecological Health Assessment of Lake Ecosystems Based on Water Quality and Plankton Hitoshi JINGUSHI (Tottori Univ.) : 3D Hydro and Water Quality Simulation in Lake Nakaumi Focusing an Artificial Dredging Hyunoh KOO (Kangwon National Univ.) : Effects of Diversion from the Soyang River on the Gongji Stream

October 12, 2010 (Tue) 09:00~11:30

Session 6 09:00~10:00 - Poster Session (10 min each)

Yeonju KIM (Kangwon National Univ.) : Study of BOD and Deoxygenation Coefficients in Imjin River Systems Soonjae YOON (Kangwon National Univ.) : Comparison of Lethality of Daphnia magna caused by Concentration Change of Ginkgo Mitsuru KITAMURA (Tottori Univ.) : Reduction of Greenhouse Gases using Wood Biomass and Domestic Wastewater Junya ARIMOTO (Tottori Univ.) : Reduction of Administrative Cost and Greenhouse Gas by Utilization of Organic Waste Hirofumi IHARA (Tottori Univ.) : A Trial to Direct Utilization of Starch in Thermophilic L-lactate Fermentation Yosuke OGAWA (Tottori Univ.) : Harvesting Stage and Extraction Solvents Effect Allelopathic Polyphenols Recovery from Trapa

Session 7 10:30~11:30 - Poster Session (10 min each)

Yuichi OGIHARA (Tottori Univ.) : Joint Management Plan of Small Water Wupply Wystems in Tottori Prefecture Yuhei SAKAI (Tottori Univ.) : Protease Produced by Bacillus coagulans Enhances a Value of Feed Keisuke NANJO (Tottori Univ.) : Biodegradation Characteristics of Particulate Matter in Eda River Yoshiya HARAFUJI (Tottori Univ.) : Growth Acceleration Effect on Plant by Bacillus coagulans Teruaki INAMI (Tottori Univ.) : Examination of Durability of Living Drainage Processing Business Which Made Towns and Villages in Tottori Example Iwao YAMAGUCHI (Tottori Univ.) :Improvement in Prediction Technology of Raw Water Pollution Risk

Closing Ceremony Professor Yoshihiko HOSOI (Tottori Univ. )The 8th Joint Symposium of Kangwon National University and Tottori University on Environmental Science and Technology. 11-13 October 2010.

Water Quality Deterioration in Aging Drinking Water Supply Pipelines

Yoshihiko HOSOI Department of Social Systems Engineering, Tottori University, Tottori city, Japan.*E-mail: [email protected]

AbstractThe population served by drinking water supply systems is 97% of total population in Japan. Most of water supply facilities are aging and replacement is required. In order to indicate necessity of replacement of aging pipelines, the effect of pipe aging on water quality was examined. The experiments on water quality in aging pipes were carried out in laboratory and actual field.The chlorine decrease rate and Fe concentration was high in grey cast iron pipe without lining. Those pipes were buried in early time of construction of water supply systems. Therefore, replacement of old pipelines is significant to maintain water supply systems at the high level.

1. IntroductionThe population served by drinking water supply systems is 97% of total population in Japan. Most of water supply facilities are aging and replacement is required. The aging of water supply pipelines affect on water quality such as coloring of water and decrease in residual chlorine. The Japan Water Research Center conducted the project named New Epoch Project which stands for New Evaluation and diagnosis of Pipeline functions by Observing pipe Characteristics. The aims of this research project were examination of water quality deterioration in aging pipelines and water quality control measures and development of diagnostic technology for the aging of pipelines. The author joined one of the research groups of the project. In this group diagnosis and evaluation methods for water quality deterioration in pipelines was examined. In order to study water quality deterioration mechanism, the effect of pipe material and water velocity on residual chlorine decrease and the relationships between pipe aging level and suspended matters were examined.

2. Effect of pipe material on residual chlorine Four test specimens were prepared for chlorine consumption laboratory test. Three of them were obtained from the buried sites, they are no lining CIP (grey cast iron pipe) of which buried year was unknown, no lining CIP buried in 1921 and mortar lining steel pipe buried in 1966, and one was new steel pipe. Diameters of all pipes were 200 mm. They were filled with water and stirred with 100rpm. Residual chlorine concentration was observed. Temporal variation of residual chlorine concentration is shown in Figure 1. In the old no lining pipes, chlorine concentration became 0 in 6 or 12 hours. Higher water temperature accelerated chlorine consumption. Chlorine gradually decreased and showed 0.7 mg/L after 24 hours in the mortar lining pipe used since 1966. In contrast, chlorine was not consumed in the new pipe.

Figure1. Change of residual chlorine concentration

The change of residual chlorine concentration is described by first order reaction equation as follows,

dC/dt=-kC (1)

where C is concentration of residual chlorine and k is reaction rate coefficient. From the equation (1), the following equation is obtained.

C=C0exp(-kt) (2)

where C0 is initial concentration. By fitting experimental results to the equation (2), the values of k were estimated as 0.150 to 0.316 for the no lining pipes and 0.015 for the mortar lining steel pipe.

Table 1 Results of field survey about chlorine consumption in actual pipelines3. Effect of water velocity and pipe aging on residual chlorine in actual pipelineThe field surveys to examine the effect of water velocity and pipe aging on residual chlorine decrease were carried out in actual pipelines in Y city and K city. Some sections of pipeline were chosen as examination sections. Two observation sites were set for each section of pipeline. The distances between two sites were from about 300m to 1200m. Residual chlorine concentration and water velocity were measured for a few days. The average velocity and k value obtained from residual chlorine concentrations are shown in Table 1. There was the largest consumption of chlorine in no lining CIP section in U district Y city. Chlorine decrease was smaller in DCIP (ductile cast iron pipe) pipeline partly equipped with no lining pipes than in the lining CIP pipeline partly equipped with no lining pipes. Slow velocity rather showed large consumption of chlorine. Comparing the results between before and after pipe replacement carried out at the section of U district Y city, it is found that chlorine consumption problem by old pipeline was significantly improved by pipe replacement. It indicates the importance and necessity of replacement of aging pipes.

4. Suspended matters in aging pipelineWhen the field survey described above was carried out, water samples were taken and filtered to analyze suspended matters. Dry weight, ignition loss, ignition mass, Al, Mn, Fe and Zn were analyzed. The concentration of suspended matters was generally higher in the downstream site than the upstream site. The concentration of inorganic matter estimated by ignition mass such as irons was greater than that of organic matter estimated by ignition loss. The concentration of Fe was far great among those of other inorganic matters. It means generation of rust in pipeline. Especially, the concentration of inorganic matters including Fe was dominantly high in the no lining CIP pipeline.

Figure 2 Relationship between Fe and k

The relationship between Fe concentration and the reaction rate coefficient of chlorine is shown in Figure 2. There is positive correlation between Fe and k. Fe concentration and chlorine consumption are large in the no lining pipelines.

5. Concluding remarks CIP pipes without lining were generally used in the early time of construction of water supply systems. Therefore, most of aging pipes are CIP without lining. This study demonstrated that chlorine consumption and concentration of Fe were dominantly greater in no lining CIP pipelines than in others. Residual chlorine is important from the point of view of water quality safety. High concentration of Fe induces color problems of water. The accumulation of rust becomes friction. It relates to water flow resistance and pressure loss. Therefore, from the point of not only water quality but also water distribution control and energy saving, replacement of aging CIP is required as soon as possible.

The 8th Joint Symposium of Kangwon National University and Tottori University on Environmental Science and Technology. 11-13 October 2010.

Fermentation of Lignocellulosic Biomass Derived Sugars to L-Lactate by Thermophilic Bacillus coagulans

S. AKAO*, Y. SAKAE, Y. HOSOI, H. NAGARE, M. MAEDA and T. FUJIWARADepartment of Social Systems Engineering, Tottori University, Tottori city, Japan.*E-mail: [email protected]

AbstractSugar assimilation of some strains of Bacillus coagulans was investigated in order to confirm whether thermophilic L-lactate fermentation can utilize lignocellulosic biomass or not. Strain JCM 2258 can produce L-lactate from wide varieties of sugars such as mannose, xylose and cellobiose. Batch fermentation of a mixture of glucose and xylose that are main derived sugars from lignocellulosic biomass was carried out. The conditions were set at 55C and pH 5.5 and sugar concentrations were set at 5 g/L, respectively. In the fermentation, xylose might be consumed simultaneously with glucose; however, complete consumption of xylose required a long period (about 2 days). Saccharification and L-lactate fermentation of whole biomass of corn without underground section was conducted as an example of lignocellulosic biomass utilization. Two kinds of cellulases (2 g/L of Meiselase and Amano 4, respectively) were used for saccharification of alkaline peroxide pre-treated biomass (50 g/L, dry weight basis). After 24 hours saccharification (45C and pH 4.5), strain JCM 2258 was inoculated. 18.7 g/L of L-lactate was produced in 4 days fermentation under non-sterile condition (55C and pH 5.5); however, long lag phase over 1 day was observed in this fermentation.

Keywords: Bacillus coagulans, lignocellulosic biomass, L-lactate, saccharification and fermentation

1. IntroductionUtilization of renewable resources, especially non-edible lignocellulosic biomass, for energy or alternative products have been urged for prevention of global warming, escape of food crisis and price stabilization of fossil fuels. Lignocellulosic biomass mainly consists of polysaccharides, which are cellulose and hemicellulose, and lignin. Polysaccharides account for about 70% by weight and have many possibilities to convert wide varieties of chemical commodities (Saha and Cotta, 2003; Patel et al, 2004; Gaspar et al, 2005); therefore, utilization of polysaccharides is one of major applications for lignocellulosic biomass. Ethanol (bio-ethanol) and L-lactate production are involved in the applications. Ethanol is familiar to us as drinking or automobile fuel, but L-lactate is also used widely in food and pharmaceutical industries. It is also used as a raw material for biodegradable polymers (poly lactic acids) and solvents (lactic acid esters), which are recognized as environmentally-benign.

In ethanol or L-lactate production, saccharification that means hydrolysis to monosaccharides is required prior to fermentation since microorganisms producing such chemical commodities metabolize monosaccharides mainly. There are two major proposed procedures for saccharification, one is acid-using and the other is enzymatic hydrolysis. Commercially biomass utilization facilities have been operated with acid-using process (http://www.bio-ethanol.co.jp/); enzymatic process has been intensively studied or applied in recent years due to its moderate reaction conditions (Nakasaki et al, 1999; Gaspar et al, 2005; Koreishi et al, 2009). We have also adopted enzymatic process for utilization of lignocellulosic biomass (Akao et al, 2010).

In enzymatic saccharification process, cellulose is hydrolyzed into glucose via cellobiose, which is one of disaccharides and behaves as an inhibitor of enzymatic hydrolysis; hemicellulose is decomposed into varieties of sugars such as xylose, arabinose and mannose. Microorganisms sort out lignocellulosic biomass derived sugars; in turn, sugar assimilation depends on species or strains of microorganisms. Saccharomyces cerevisiae and Zymomonas mobilis, which are representative ethanol producing microorganisms, cannot utilize hemicellulose derived sugars naturally; therefore, genetically modified organisms have been developed and applied to utilization of those sugars (Lawford and Rousseau, 2002; Matsushika et al, 2009).

On the other hand, some species or strains of L-lactate producing bacteria can metabolize hemicellulose derived sugars (Hofvendahl and Hahn-Hagerdal, 2000; Tanaka et al, 2002). Moreover, cellobiose utilization by L-lactate producing bacteria has been announced recently (Adsul et al, 2007; Romero et al, 2009). One of strains of Bacillus coagulans, which is newly thermophilic L-lactate producing bacteria (Rosenberg et al, 2005), has been reported to utilize pentose efficiently (Patel et al, 2006). We have also proposed unique thermophilic L-lactate fermentation process using B. coagulans with 55C and pH 5.5 conditions, which can be carried out non-sterile fermentation (Akao et al, 2007); therefore, we have aimed to combine lignocellulosic biomass utilization and non-sterile L-lactate fermentation.

In this paper, we describe the strain that can produce L-lactate from lignocellulosic biomass derived sugars under thermophilic L-lactate fermentation conditions. Xylose utilization process, main monosaccharide derived from hemicellulose, is also discussed. As an example of lignocellulosic biomass utilization, we demonstrate enzymatic saccharification and L-lactate fermentation of whole biomass of corn, which is used for animal feed.

2. Materials ans MethodsOrganism, biomass and materialsB. coagulans JCM 2257, JCM 2258 and JCM 9076 were purchased from Riken Bioresource Center as L-lactate producers. Each strain was incubated in LB medium (Bacto Tryptone 10g/L, Bacto Yeast Extract 5 g/L, NaCl 10 g/L, 5 M NaOH solution 0.2 mL) at 55C for 2 days with shaking and stored at room temperature (stock culture). Cellulases which were Meiselase (Meiji Seika Kaisha, Ltd.) and Amano 4 (Amano Enzyme Icn.) were obtained from each supplier. Whole biomass of corn for animal feed (KD730) without underground section was used for saccharification and sequential L-lactate fermentation. The biomass that was grown in Kochi University and harvested in about 60 days in summer had not produced corn grains. Corn biomass was dried at 70C for 2 days, milled for 5 minutes with an electronic coffee grinder and kept in a desiccator until use. Analytical grade reagents were purchased from Wako Pure Chemical Industries, Ltd.

Sugar assimilation testCulture media was mixed equal amount of mineral solution and sugar solution. The mineral solution consisted of Bacto Yeast Extract 10 g/L, (NH4)2HPO4 1 g/L, MgSO47H2O 0.2 g/L, MnSO44H2O 0.04 g/L, FeSO47H2O 0.02 g/L (Rosenberg et al., 2005) and CaCO3 10 g/L for pH adjustment. 10 g/L of sugar solutions (glucose, mannose, fructose, galactose, xylose, arabinose, cellobiose, soluble starch, corn starch, cellulose/microcrystalline (Alfa Aesar, Avocado), pectin) were prepared in this test. The mineral solution and the sugar solutions were autoclaved (121C, 20 minutes) separately. 10 mL of culture media was added to 15 mL sterile disposal tube; stock cultures of the three strains above mentioned in LB media were planted with sterile inoculating needle. Those cultures were incubated for 48 hours at 55C with shaking. After incubation, D-,L-lactate concentration was determined by HPLC. Each case on eleven types of sugars and three types of strains was carried out six times and the first through the third data from the top of L-lactate production yield on each case were evaluated.

Thermophilic L-lactate fermentation of glucose and xyloseMineral solution consisting of 4 g of Bacto Yeast Extract and 4 g of Bacto Tryptone in 200 mL (Payot et al., 1999) and sugar solutions consisting of 4 g of glucose, 4 g of xylose or 2 g of glucose and xylose, respectively, in 200 mL were autoclaved separately. These solutions were added into 500 mL Erlenmeyer flask, in which L-lactate fermentation was conducted with 4 mL of stock culture as inoculum. The fermentation conditions were set at 55C in a hot water bath and pH 5.5 (Akao et al, 2007). A pH-controller (NPH-660, Nisshin-rika Ltd.) with a peristaltic pump maintained the given pH value using 5 M ammonium hydroxide solution. Magnetic stirrers mixed culture broth. Nitrogen gas was purged to the flasks before starting fermentation. Aliquots of the fermented broth samples were collected periodically and determined for D-,L-lactate concentration, monosaccharides concentration and colony forming units (CFU).

Pre-treatment of corn biomassAlkaline peroxide treatment was applied as a pre-treatment for saccharification of corn biomass (Saha and Cotta, 2003). Firstly, 10 g of milled biomass and 100 mL of 1% sodium hydroxide solution were added to 200 mL beaker. The slurry was kept for 12 hours with random stirring. Next, 1 mL of 30% hydrogen peroxide solution was added to the beaker and kept for 12 hours with random stirring. This pre-treatment was carried out under room temperature. Solid-liquid separation was conducted with centrifugation (about 1000g for 10 minutes). Collected biomass was washed three times using 0.1 M sodium acetate buffer (pH 4.5) and dried at 70C for 2 days. After drying, the biomass was grinded in a mortar and kept in a desiccator until use for saccharification. Recovery rate of biomass in pre-treatment based on dried weight was measured in duplicate.

Saccharification and thermophilic L-lactate fermentation of corn biomass5 g of pre-treated biomass and 2 g of Bacto Yeast Extract were added into 100 mL of glass bottle, which was a reactor for saccharification and sequential L-lactate fermentation, and autoclaved (121C, 20 minutes). Saccharification was conducted in cellulases solution (2 g/L of Meiselase and Amano 4, respectively, in distilled water). 100 mL of the solution was poured into the reactor. The condition was set at 45C in a hot water bath and pH 4.5 with a pH-controller and peristaltic pumps using 1 M hydrochloric acid and 5 M sodium hydroxide solution. A magnetic stirrer was used for constant mixing. Duplicate incubations were carried out for 24 hours. Following thermophilic L-lactate fermentation was conducted after the saccharification. 1 ml of stock culture of B. coagulans JCM 2258 was inoculated into each reactor. The fermentation conditions were set at 55C and pH 5.5. Aliquots of the fermented broth samples were collected periodically and determined for D-,L-lactate and monosaccharides concentrations by HPLC.

AnalysisD-,L-Lactate concentration was determined by HPLC (mobile phase, 5% 2-propanol and 1 mM CuSO4 solution; column, SUMICHIRAL OA-5000, SCAS Ltd.; UV detector, 254 nm). Monosaccharide concentrations were also analyzed by HPLC (mobile phase, deionized water; column, SUGAR SP0810, Shodex; detector, refractive index detector). CFU was determined for counting thermophilic acid-producing bacteria using Dextrose Tryptone Agar (Difco) incubated at 55C for 24 hours.

3. Result and DiscussionSugar assimilation test

Figure 1. Summaries of sugar assimilation test by Bacillus coagulans.10 g/L of each sugar was utilized. l-Lactate yield was calculated based on initial sugar weight. Each case was conducted six times and the 1st through the 3rd data from the top of the yield were evaluated.L-Lactate production from several sugars was investigated in order to seek the strain that can metabolize derived sugars from lignocellulosic biomass in particular. Figure 1 presents L-lactate yields from given sugars based on initial weight. D-Lactate was not detected in this test. Strain JCM 2258 utilized wide varieties of sugars with relatively high yields that include the derived sugars such as mannose, galactose, xylose and arabinose. Cellobiose was also utilized by strain JCM 2258 despite little information about cellobiose assimilation (Adsul et al, 2007; Romero et al, 2009). Cellobiose is usually hydrolyzed with added -galactosidase to glucose in enzymatic saccharification using cellulase (Koreishi et al, 2009); therefore, the feature of utilization of cellobiose would be advantage in enzymatic saccharification. Sugar assimilation test indicates that strain JCM 2258 would be preferred to be used for thermophilic L-lactate fermentation of lignocellulosic biomass. In turn, thermophilic L-lactate fermentation can utilize derived sugars from lignocellulosic biomass and this is one of advantages of the fermentation for production of alternatives to fossil fuels. S. cerevisiae and Z. mobilis, which are ethanol producing microorganisms, cannot metabolize xylose, arabinose and mannose naturally. In the following fermentation, strain JCM 2258 was used.

Thermophilic L-lactate fermentation of glucose and xyloseBatch fermentation was conducted in order to confirm glucose or xylose consumption, L-lactate production and time variation of viable bacterial counts (CFU) since strain JCM 2258 can metabolize xylose. D-Lactate was not produced in this and following fermentation. Figure 2 indicates that lag phase, L-lactate producing rate and time variation of viable bacterial counts were different on sugar types. It would result from the difference of metabolic pathways, which are EMP pathway and pentose-phosphate/phosphoketolase pathway (Patel et al, 2006). Glucose provided rapidly L-lactate production and bacterial growth; however, cumulative amount of viable bacteria in xylose case were larger than that in glucose case if about 106 CFU/mL was consider as the baseline. Long-period observation of viable bacterial counts in stock culture (LB media) revealed that the counts would stabilize at between 106 and 107 CFU/mL (Figure 3). This means that xylose might sustain larger amount of thermophilic L-lactate producing bacteria than glucose. Patel et al (2005) have obtained the same result of bacterial cell mass between glucose and xylose and pointed out that larger cell mass would compensate low L-lactate production rate in some degree. In L-lactate yield, that of xylose is generally lower than that of glucose based on weight. Theoretically, L-lactate yield through EMP pathway for glucose and pentose-phosphate pathway for xylose are equal based on weight (1.0 g/g). However, L-lactate yield through phosphoketolase pathway for xylose is 0.6 g/g based Figure 2. Time courses of l-lactate, glucose and xylose concentrations and viable bacterial counts in thermophilic l-lactate fermentation (left, glucose; right, xylose).10 g/L of each sugar, Bacto Yeast Extract and Bacto Tryptone, respectively, were used.on weight (Patel et al, 2004, 2006). On the other hand, ATP yield through phosphoketolase pathway (6.8 g/g) is higher than that through EMP pathway and pentose-phosphate pathway (5.6 g/g). Xylose metabolic pathway has also been reported to be shifted depending on xylose concentration (Tanaka et al, 2002). Xylose metabolic pathway was vague in this fermentation, but lower L-lactate yield might result from higher ATP yield and bacterial yield.

Figure 3. Time courses of viable bacterial counts in stock culture (LB media).Heat treatment (70C, 30 minutes) was carried out for counting of spores of B. coagulans.The fermentation of a mixture of glucose and xylose was also carried out (figure 4). In this fermentation, xylose was consumed simultaneously with glucose consumption; however, complete consumption of xylose required a long period (about 2 days). Viable bacterial counts were once decreased after rapid growth in figure 4; bacteria utilizing glucose did not utilize xylose immediately after depletion of glucose. L-Lactate production rate and viable bacterial counts were, however, increased in the final stage of the fermentation in figure 2 and figure 4. Induction of enzymes for xylose metabolic pathway by B. coagulans might call for long time. In order to utilize xylose in thermophilic L-lactate fermentation, large amount of bacteria utilizing xylose should be kept in a reactor with continuous xylose feeding. Continuous fermentation with attached media might be suitable considering not requiring sterilization in thermophilic L-lactate fermentation, which is one of advantages (Rosenberg et al, 2005; Akao et al, 2007).

Figure 4. Time courses of l-lactate, glucose and xylose concentrations and viable bacterial counts in thermophilic l-lactate fermentation.5 g/L of each sugar and 10 g/L of Bacto Yeast Extract and Bacto Tryptone were used.Figure 5. Batch thermophilic l-lactate fermentation of whole biomass of corn hydrolysate. 50 g/L of alkaline peroxide pre-treated biomass was saccharified using 2 g/L of Meiselase and Amano 4, respectively, for 24 hours. The fermentation was conducted duplicate and averages were shown in the figure.Pre-treatment, saccharification and thermophilic L-lactate fermentation of corn biomassAlkaline peroxide pre-treatment of whole biomass of corn was conducted. Biomass recovery rate was 0.69 g/g based on initial weight in the pre-treatment process. Indeed concentration of monosaccharides in waste water of the pre-treatment were marginal (its loss rate was under 0.01 g/g), some amount of oligo- and polysaccharides might be also lost (Gaspar et al, 2005). It would be preferable to utilize these mono-, oligo- and polysaccharides for fermentation although we did not use those sugars in this study.

Saccharification of pre-treated biomass and following L-lactate fermentation of the hydrolysate was conducted (figure 5). In the fermentation, consumption of glucose and xylose were confirmed. High L-lactate yield based on initial amount of glucose and xylose (0.88 g/g) was also obtained, which was almost same as Patel et al (2004). On the other hand, long lag phase over 1 day was observed in this fermentation. We also observed long lag phase several times when using whole biomass of corn and sorghum hydrolysate (data not shown) although the lag phase did not emerge in the references nor in our previous study using whole biomass of Trapa (Akao et al, 2010). Some inhibitors might be produced at pre-treatment or saccharification stage. In the chromatogram for D-,L-lactate analysis, some peaks that existed at the beginning of the fermentation disappeared after starting of L-lactate production. We dont know whether those peaks are inhibitors or not, but continuous exposure of inhibitors might shorten the lag phase, i.e. inducing some enzymes for removing inhibitors. Continuous fermentation with attached media might be suitable at this point.

4. ConclusionsIn order to confirm whether thermophilic L-lactate fermentation can utilize lignocellulosic biomass or not, sugar assimilation of the fermentation was investigated. We also conducted the fermentation of glucose and xylose, which are main derived sugars from lignocellulosic biomass, and hydrolysate from whole biomass of corn without underground section. Major findings in this study are as follows:(1)B. coagulans JCM 2258 can metabolize wide varieties of sugars such as mannose, galactose, xylose, arabinose and cellobiose with relatively high L-lactate yield (over 0.6 g/g based on weight). In turn, thermophilic L-lactate fermentation can utilize lignocellulosic biomass derived sugars.(2)Batch fermentation of a mixture of glucose and xylose indicated that xylose might be consumed simultaneously with glucose; however, complete consumption of xylose required a long period. Time variation of viable bacterial counts presented that bacteria utilizing glucose did not immediately utilize xylose after depletion of glucose.(3)Batch fermentation of corn biomass hydrolysate was conducted and 0.37 g/g of L-lactate yield based on pre-treated biomass weight was obtained. Glucose and xylose consumption was also confirmed in the fermentation. On the other hand, production of L-lactate fermentation inhibitors at pre-treatment or saccharification stage might be pointed out since long lag phase (over 1 day) was observed.

Acknowledgement

This work was supported by JST, CREST. We also thank Riken Bioresource Center for the supply of microbial strains and Meiji Seika Kaisha Ltd. for the supply of Meiselase.

References

Adsul, M., Khire, J., Bastawde, K. and Gokhale, D. 2007 Production of lactic Acid from cellobiose and cellotriose by Lactobacillus delbrueckii mutant Uc-3. Appl. Environ. Microbiol. 73(15), 5055-5057.Akao, S., Tsuno, H., Horie, T. and Mori, S. 2007 Effects of pH and temperature on products and bacterial community in L-lactate batch fermentation of garbage under unsterile condition. Water Res. 41(12), 2636-2642.Akao, S., Sakae, Y., Nakatani, S. and Hosoi, Y. 2010 Simultaneous saccharification and L-lactate fermentation of an aquatic plant (Trapa) under unsterile condition by Bacillus coagulans. Proceedings of World Water Congress and Exhibition, Montreal. In Press.Gaspar, M., Juhasz, T., Szengyel, Z. and Reczey, K. 2005 Fractionation and utilisation of corn fibre carbohydrates. Proc. Biochem. 40(3-4), 1183-1188.Hofvendahl, K. and Hahn-Hagerdal, B. 2000 Factors affecting the fermentative lactic acid production from renewable resources. Enzyme Microb. Technol. 26(2-4), 87-107.Koreishi, M., Imanaka, H., Imamura, K., Kariyama, M. and Nakanishi, K. 2009 Efficient ethanol production from wheat bran by enzymatic saccharification using commercially available enzyme products and fermentation using bakers yeast (in Japanese). Seibutu-Kougaku Kaishi 87(5), 216-223.Lawford, H. and Rousseau, J. 2002 Performance testing of Zymomonas mobilis metabolically engineered for cofermentation of glucose, xylose, and arabinose. Appl. Biochem. Biotechnol. 98-100(1-9), 429-448.Matsushika, A., Inoue, H., Kodaki, T. and Sawayama, S. 2009 Ethanol production from xylose in engineered Saccharomyces cerevisiae strains: current state and perspectives. Appl. Microbiol. Biotechnol. 84(1), 37-53.Nakasaki, K., Akakura, N., Adachi, T. and Akiyama, T. 1999 Use of wastewater sludge as a raw material for production of L-lactic acid. Environ. Sci. Technol. 33(1), 198-200.Patel, M., Ou, M., Ingram, L. and Shanmugam, K. 2004 Fermentation of sugar cane bagasse hemicellulose hydrolysate to L(+)-lactic acid by a thermotolerant acidophilic Bacillus sp. Biotechnol. Lett. 26(11), 865-868.Patel, M., Ou, M., Ingram, L. and Shanmugam, K. 2005, Simultaneous saccharification and co-fermentation of crystalline cellulose and sugar cane bagasse hemicellulose hydrolysate to lactate by a thermotolerant acidophilic Bacillus sp. , Biotechnol. Prog. 21(5), 1453-1460.Patel, M., Ou, M., Harbrucker, R., Aldrich, H., Buszko, M., Ingram, L. and Shanmugam, K. 2006 Isolation and characterization of acid-tolerant, thermophilic bacteria for effective fermentation of biomass-derived sugars to lactic acid. Appl. Environ. Microbiol. 72(5), 3228-3235.Payot, T., Chemaly, Z. and Fick, M. 1999 Lactic acid production by Bacillus coagulans: Kinetic studies and optimization of culture medium for batch and continuous fermentations. Enzyme Microb. Technol. 24(3-4), 191-199.Romero, S., Hernndez, B., Merino, E., Gosset, G. and Martinez, A. 2009 Homolactic fermentation from glucose and cellobiose using Bacillus subtilis. Microbial Cell Factories. 8, 23.Rosenberg, M., Rebros, M., Kristofikova, L. and Malatova, K. 2005 High temperature lactic acid production by Bacillus coagulans immobilized in LentiKats. Biotechnol. Lett. 27(23-24), 1943-1947.Saha, B. and Cotta, M. 2007 Enzymatic saccharification and fermentation of alkaline peroxide pretreated rice hulls to ethanol. Enzyme Microb. Technol. 41(4), 528-532.Tanaka, K., Komiyama, A., Sonomoto, K., Ishizaki, A., Hall, S. and Stanbury, P. 2002 Two different pathways for D-xylose metabolism and the effect of xylose concentration on the yield coefficient of L-lactate in mixed-acid fermentation by the lactic acid bacterium Lactococcus lactis IO-1. Appl. Microbiol. Biotechnol. 60(1-2), 160-167.


Relationship between Hydrodynamics and Removal Effect of Periphyton by Artificial Flood in the Hoo Stream (Korea)

Hiroshi YAJIMA1*, Sungmin JUNG2, Misook PARK2, Jaeyong LEE2, Bomchul KIM2 and Changkun PARK31 Department of Social Systems Engineering, Tottori University, Tottori city, Japan.2 Department of Environmental Science, Kangwon National University, Chunchon, 200-701, Korea3 Department of Civil Engineering, Kwandong University, Kangnung, Korea*E-mail: [email protected]

AbstractWe jointly conducted artificial floods in the downstream of the Yangyang pumped storage power plant dam, in Gangwon-Do. The purpose of this experiment is to remove periphyton biomass in the river. Before and after artificial flood events, periphyton biomass was measured and compared at 6 sites in the downstream reach of the dam. We also conducted 2-D vertically averaged steady flow model simulations to evaluate shear stress in the river bed.Periphyton biomass was clearly reduced after the artificial flood. It was effective up to the distance of about 4km from the dam. Removal rates of attached algae ranged from 3 to 46%. The results of the simulations along with the analysis of periphyton revealed that larger shear stress areas under the normal flow condition have more algae than smaller shear stress areas before the flood event but these characteristics became unclear after the event.

Keywords: Artificial flood, 2-D hydrodynamic model, flow velocity, removable rate, periphyton.

1. Introduction The local, or site-specific, alterations caused by dam have been studied extensively over the last few decades. Storage of water and capture of sediment by dams caused profound downstream changes in the natural patterns of hydrologic variation and sediment transport, which has often leaded the degradation of the environment for downstream of a dam. One of the common problems is attached algae on the bed materials and moreover siltation on the bed load and stagnant water with bad odor can be often the case. In Japan, some artificial flood experiments using sands were conducted in order to remove attached algae (ex. Sagae Dam, Miharu Dam and Sogurigawa dam). It is considered that each algae has different attached toughness and they can grow depending on the shear stress by flows. Nevertheless we do not have the quantitative analysis between the shear stress and the toughness of algae. In order to study the effect of flood events on periphyton sloughing, we conducted surveys for artificial floods with sand supply in the Hoo Stream that flows through the eastern part of Korea.

2. Method and materials The river for the experimental area is located in the downstream of the Yangyang pumped storage power plant dam (Figure 1). The study area has been suffering from turbidity problems caused by shore erosion of the dam, and the accumulation of inorganic sediments and attached algae on the river bottom is the major factor of aquatic habitat deterioration. The deposition of sediments and attached algae is believed to have been enhanced by the regulation of flood and blocking of sediment supply by the construction of dam. Therefore, in order to restore naturalness of the stream habitat, artificial flood discharge from the dam and artificial addition of sand at the discharge point of the dam was suggested as a curative of periphyton increase problem (Figure 2).

Figure 1. Map of study area

Figure 2. A rock covered with periphyton

The artificial floods were conducted in 2008, 2009 and 2010. The amount of water discharge for each flood event was from 300,000 to 600,000 m3. For the event of 7th July, 2010 and its total flooding volume was approximately 500,000 m3. Before and after the flood we sampled the attached algae and inorganic sediment on gravels. And we also measured water quality (turbidity and chl-a) by every 5-minute auto-logging at two stations and water depth by every 1-minute at 5 stations during the flood. Before and after artificial flood events periphyton biomass was measured and compared at 6 sites in the downstream reach of the dam. At each site 5 - 10 substrate were measured across the river at the interval of 1 - 2m. Periphyton was collected by scraping a 5cm x 5cm area with a brush and chlorophyll a concentration and inorganic sediment. Moreover we conducted 2-D vertically averaged steady flow model simulations based on the Navier-Stokes equations. The model we used is called iRIC, which is under development by the informal group of scientists and engineers working together to make river modeling software. We evaluated the velocity and bottom shear stress distribution for two flow conditions (one for the maximum flood discharge during the event and the other is for a normal flow rate).

3. Result Figure 3 shows the example result of 3-D hydraulic simulation model.

Figure 3. Example result of 2-D hydraulic simulation model.

Table 1 shows the relationship between distribution of periphyton biomass and removal rate. In this table, 100 mg Chla/m2 is nuisant eutrophic level. We can see 20-80 % of periphyton was removed by an artificial event. And removal rate was higher near the dam discharge point. Moreover removal is effective down to 4 km from the dam discharge.

Table 1. Distribution of periphyton biomassand removal rate.

Figure 4 and Figure 5 show the comparison of friction velocity and periphyton biomass and removal rate. From Figure 4, it can be seen that the stations with high friction velocity for the average flow have more periphyton biomass. This suggested that the species of periphyton biomass are different depending on the friction velocity for the average flow and more biomass can grow in the area of higher friction velocity. On the other hand, we cannot see any relationship between the friction velocity for the flood and removal rate.

Figure 4. Comparison of friction velocityand Periphyton biomass.

Figure 5. Comparison of friction velocityand removal rate.

4. ConclusionPeriphyton biomass was clearly reduced after the artificial flood. And it was effective up to the distance of approximately 4 km from the dam. The river sections with larger shear stress for the ordinary discharge seems to have more periphyton biomass. We could not see the clear relationship between the removal rate and shear stress. Algaes species and the movement of sand and silt might have the influence.In order to make an artificial flood event efficiently, we should evaluate the shear stress considering the algal attached toughness and sediment transport before flood events using a hydrodynamic model.


Planning of Efficient Garbage Collection System in Depopulation Areas

Ichiro WALIMOTO*, Yoshihiko HOSOI and Takanori MASUDADepartment of Social Systems Engineering, Tottori University, Tottori city, Japan.*E-mail: [email protected]

AbstractPopulation is decreasing in most rural areas. Expansion of garbage collection area should be taken into consideration to make garbage disposal plan of those areas from the long term perspective. The optimal sites and number of incineration plant and garbage collection areas are affected by population and its distribution. Therefore, planning of garbage disposal system should be based on the estimation of change of population and its distribution in order to seek cost efficiency. In this study, a model treatment area is used to examine garbage disposal cost for 20 years. And the effects of incineration plant management plans and depopulation patterns on garbage disposal cost are examined.

Keywords:, garbage, incineration plant, cost, plan, collection system, depopulation area,

1. IntroductionNational population has been decreasing since 2006 in Japan and sparsely-populated areas are growing [1]. In addition, the percentage of elderly people is increasing. Change of population composition gives local society structure various effects. For incineration plants, Japanese government asks to construct large plants which operate 24 hours a day when intermittent operating plants are renewed. This wide-area plan is contrary to method of managed several small scale incineration plant as traditional, method of consolidate a large incineration plant in area. The large incineration plant can reduce dioxin emissions, implement thermal recycle and reduce running cost. At the same time, wide-area plan is not only merit. In contrast, the expansion of collection area increases collection cost. Herewith if expand range of wide area plan in large excess, have prospects of high cost for waste collection cost than reduce garbage disposal cost. There is trade-off between garbage disposal cost and collection cost in the expansion of collection area. Especially, it is significant problem in sparsely populated area, because collection cost becomes high to collect certain amount waste with the objective of effective garbage disposal. In addition, the service life of an incineration plant is 20 or 30 years. Even if the plants are constructed at the optimal sites from the point of current population, there is a possibility that it is not optimal solution in future population because of population decrease and change of population distribution.Planning of garbage disposal system should be based on the long term perspective of population decrease and change of population distribution in plant service life. The choice of strategies among construction, prolongation and integration of incineration plants and its timing are important under the condition of population decrease.

2. Purpose of a researchIn this study, the effect of management of incineration plants on disposal cost is examined and optimal management plant which glues the least cost is determined. A few management plans of incineration plants in the model area are designed. Their costs are calculated and compared to each other. Differences of cost due to depopulation patterns are also examined.

3. Method of a research The model area is shown in Figure 1 which is rectangle with 40 km length and 20 km width. Incineration plants are constructed in the area and garbage disposed at each mesh is transported to the plant.

Figure1. Model treatment areas

The amount of garbage is proportional to the population of the mesh. The population is given as shown in Figure 2. Initial condition is 1000 people in all meshes, and total population is 800,000 people. The population of each mesh constantly decreases every year for 20 years.

PopulationInitial condition

1000 people

750 people

500 people

250 people

1000 people/mesh800 meshes

Pattern 1

500 people/mesh800 meshes

Pattern 2

750 people/mesh400 meshes250 people/mesh400 meshes

B areaA area 3 patterns population decreases are assumed. In pattern 1, all meshes have same decreasing pattern. In pattern 2, left side (A area) districts have larger decrease than right side districts. Pattern 3 is opposite decrease (B area) pattern to pattern 2. Population is 400,000 people after 20 years in all patterns.Initial condition is that there are two plants, plant A is in area A and plant B is in area B. Plant A can be used 5 years, plant B however, can not be used still more. Either incineration plant can not treat garbage in whole areas. There are three alternatives of plant management describe as follows (Figure 3). In Type 1, plant B is prolonged for 5 years with restoration. A new plant which treats garbage from all meshes is constructed after 5 years. In Type 2, a new plant same as plant B is constructed now. Plant A is also renewed after 5 years. In Type 3, a new plant which can treat garbage from all meshes is constructed now.The total cost of 3 types with 3 population decreasing patterns for 20 years are examined.

4. References Book[1] Japanese Ministry of the Environment: White paper on environment in 2006

Figure2. Depopulation patterns

Tenure of useIncineration plantRemainder yearsSelectionCourse of time20 yearsTYPE 0Plant A15 years5 yearsPlant B20 yearsPlant CTYPE 3After 20 years20 years15 years5 yearsPlant ATYPE 2Plant CPlant DPlant C20 years15 years5 yearsAfter 5 yearsAfter 15 years20 years15 years5 yearsPlant ATYPE 1Plant B5 yearsPlant C20 yearsAfter 5 yearsAfter 15 years

Figure3. Incineration plant management plans The 8th Joint Symposium of Kangwon National University and Tottori University on Environmental Science and Technology. 11-13 October 2010.

Effect of Surface Condition of Paddy Field on Pollutants Runoff during Non-irrigation Period

Hyungjun LEE*, Takanori MASUDA and Yoshihiko HOSOI Department of Social Systems Engineering, Tottori University, Japan.*E-mail: [email protected]

AbstractThe aims of this study are to identify the effect of surface condition of paddy fields on pollutants runoff and quantify the pollutant loading during non-irrigation period. Water samples drained from land surface and culvert were collected in four types of paddy fields during three rain events. From the result of the survey, we identified that amount of flow and substance concentration are affected by surface condition after harvest, and flow rate is an important factor for pollutants loading outflow. On the basis of surveys results, we made a regression model to quantify runoff loading during non-irrigation period. According to the results of model analysis, if rainfall will increase in some region by global warming, pollutants loading will increase dramatically in the future. To reduce pollutants loading runoff, it seems effective to set a weir near surface outlet and close culvert which focused on prevention of flow rate discharge.

Keywords: surface conditions; pollutants loading; non-irrigation period

1. Introduction

(a) Type A1(b) Type B1(c) Type C1(d) Type E1Fig. 1 Surface condition of study paddy fieldsThere are many studies which focus on pollutants during irrigation period, because farmers used much water and fertilizers. However, we should not ignore pollutants loading during non-irrigation period while there are no irrigation activities. When it is rain, pollutants materials are easily drained out by rainfall from surface and culvert which always open during non-irrigation period. In this study, we carried out rainfall survey during non-irrigation period to identify the effect of surface condition of paddy field on pollutants loading. The purposes of this study are to identify the pollutants runoff characteristics and to propose effective methods for reducing pollutants runoff.2. Method and materials The study area is the Obatake area which is located around Lake Koyama in Tottori prefecture, Japan. We selected four types of paddy fields according to difference of surface condition after harvest. Figure 1 illustrates the surface condition of paddy fields. Type A is an untouched paddy field, Type B is a ploughed paddy field, Type C is a paddy field on which straws were scattered after harvest, and Type E is a fallow field. Type E was paddy field until 2005.Water samples were collected from surface and culvert outflow in four types of paddy fields during three rain events on 5th December 2008, 30th January and 10th November 2009. Total precipitation in each event was 23mm/13hr, 23mm/10hr and 81mm/40hr, respectively. Flow rate was calculated by time check during collecting water. We measured SS, VSS, T-N, DTN, NH4-N, NO3-N, T-P, DTP and PO4-P by Japanese standard analysis methods.

3. Result Figure 2 shows the cumulative flow rate and pollutants loading in 10th November in 2009. We identified that flow rate from surface runoff is largest in type A among the paddy fields. We thought that lots of flow rate from surface is caused by surface state in type A. There are no activities in type A. So it makes a difficult condition for rainfall water to infiltrate into land. On the other hands, flow rate was low in type B and C. We consider that rainfall water is easily infiltrate into a land in cultivated paddy field like type B, and rainfall water is adsorbed by spreading straws in type C. Among the paddy fields, the order of SS, T-N and T-P loading amount was same with the order of flow rate. Although we couldnt show concentration data in this abstract, we identified that pollutant loading was affected by not concentration but flow rate. From the 3 rainy event surveys, we made R-Q models on the basis of relationship between rainfall Fig. 2 Comparison of pollutants loading in November 2009and flow rate, and we made L-Q models on the basis of relationship between flow rate and runoff loading. These models can calculate pollutants loading for rainfall of 4~81mm per day. We consider 1st October ~ 30th April as non-irrigation period. Daily precipitation is used as input data of the model. The sum during the period is regarded as pollutant loading during non-irrigation period. To apply the models, we selected three years according to precipitation, in 2006 (less than average precipitation; 752mm), 2002 (average precipitation; 1152mm) and 2004 (more than average precipitation; 1536mm). The results are shown Figure 3. And we compared 2004s results with unit loading of irrigation period (LEE, 2008) in Figure 4. As the result, pollutants unit loading of non-irrigation period accounted for 15~51% in type A, 4~7% in type B, 1~7% in type C and 34~42% in type E compared with irrigation period unit loading. We can see easily paddy fields like type A and fallow fields like E are getting increase in Japan with aging society. Therefore, runoff loading from type A and E during non-irrigation period cant be ignored and it should be controlled.

Fig. 3 Result of estimated loading during non-irrigation period Fig. 4 Unit loading comparison

4. ConclusionFrom the models, it was estimated that type A and type E discharged lots of pollutants loading during non-irrigation period. It seems that main factor is not concentration but flow rate. Pollutants loading will be reduced by controlling concentration or flow rate. When you want to control concentration, no management is good for water quality without ploughing paddy fields or scattering straws on it after harvest. On the other hand, pollutants loading also can be reduced by flow rate control. For example, surface runoff can be reduced by ploughing paddy fields and setting a weir near the surface outlet, and culvert runoff can be reduced by closing the culvert outlets. Both methods are effective to reduce water runoff to canals directly during non-irrigation period.

ReferenceHyungjun LEE, Takanori MASUDA, Yoshihiko HOSOI (2008) : Study on Characteristics and Pollutant Loading of Particulate Matter discharged from small Agricultural area. Environmental Engineering Research. vol.45. pp.9-17 (in Japanese)


Long-term Variation of Water Quality in the Lower Han River

Myoungsun SHIN, Jaeyong LEE, Bomchul KIM*Department of environmental science, Kangwon National University, Chunchon, Korea.*E-mail: [email protected]

AbstractAvailability of long-term data are critical when evaluating trends in water quality, processes and functions of biotic systems, ecosystem health and many other ecosystem functions or values. This study reports on trends in water quality in the lower Han River, Korea. Some of the water quality parameters we measured were BOD, COD, and total phosphorus and river discharge (from Paldang Dam). The long term average of BOD was 1.820.67 mg/L and it showed a decreasing trend, while COD did not vary consistently with the long-term average of 3.460.87 mg/L. Based on these trends, the BOD/COD ratio has decreased. This pattern might be related to the change of character of organic matter in the Han River, with an increasing ratio of (nonbiodegradable organic matter/total organic matter). Total phosphorus concentration did not show a consistent long-term trend, but seasonal variation in total P needs to be accounted for. Concentrations of total phosphorus were especially elevated during high water discharge periods of summer monsoon. Overall, our results show that BOD has decreased in the lower Han River system, but nonbiodegradable organic matter concentrations have increased. In order to document continued improvements in water quality in the Lower Han River, not only must monitoring continue, but monitoring of additional parameters, and more sophisticated measurement tools and approaches are needed.

Keywords: Long term trend, Han River, water quality, summer monsoon

1. Introduction

This study is to report on trends in water quality, and find a major factor of causing of changes of water quality in the Lower Han River.

2. Method and materials Data was collected from 2 methods. One part is data for long term trend, the others is data for seasonal variation. For the long term trend analysis, data got from Korea Water Resources Corporation (www. wamis.go.kr) during 1989 to 2006. For the seasonal variation, I investigated water quality in the lower Han River monthly during March, 2005 to July, 2010.

Gui Gui Figure 1. Study site(the Lower Han River).

3. Result The long term average of BOD was 1.820.67 mgO2/L and it has decreasing trend. Average of COD was 3.460.87 mg/L and it did not decrease like BOD trend. Based on these trend, BOD/COD ratio has decreased.

Figure 2. Long term trend of water quality constituent for 19 years.

Figure 3. Seasonal variation of suspended solids in the lower Han river during study period.

Figure 4. Comparison of concentration between Paldang Dam and the Lower Han River.

4. Conclusion- BOD has a decreasing trend, but COD is not decreasing.-BOD/COD ratio has a decreasing trend, it means this pattern might be related to the change of character of organic matter(increasing ratio of nonbiodegradable organic matter/total organic matter).-TP was 63.357.4 mgP/L which is at eutrophy level. Phosphorus did not decrease.- TN conc. was 2.521.22 mgN/L with increasing trend.


Total Dissolved Gas Supersaturation and its Effect in the Downstream of a Large Dam

Saeromi LEE, Bomchul KIMDepartment of Environmental science, Kangwon National University, Korea.

Introduction

When it comes to aquatic organisms and dissolved gases, more is not always better. Gas supersaturation can be harmful to aquatic life of various forms. Seasonal and other temporal variations in supersaturation may occur. Water can become supersaturated with atmospheric gases through various means. Supersaturation may also result from the mixing of waters of different temperatures, a decrease in hydrostatic or other confining pressure, or ice formation. The primary sign of gas supersaturation is the formation of bubbles on submerged surfaces or within the vascular systems and tissues of aquatic organisms.

Definitions and Caculations

Total dissolved gas(TDG) is an amount of gases, typically the constituents of air, dissolved in water. Usually measured as pressure or percent of saturation relative to ambient barometric pressure(BP).

TGP (%) = (TGP/BP)100

TGP is total gas pressure. P, the preferred variable for indicating hyperbaric or hypobaric conditions, represents the difference between TGP and BP(B.J. Watten and D.R. Smith, 1997). P (mmHg) = TGP BP

Why did TDG supersaturated?

Generally TDG supersaturation regulation is an issue associated with dams that potentially spill water or cooling water effluents that substantially raise the temperature of saturated water. These sources are present on major rivers and estuaries where there is commonly sufficient depth to provide compensation for the TDG supersaturation. Naturally produced TDG supersaturation can also occur in smaller and shallower streams downstream from falls and some rapids where there is little depth available for compensation(Don.E.Weitkamp Ph.D., 2008).

Hydrostatic compensation (depth)

TDG supersaturation is nearly always described in reports and regulations as relative to surface (ambient atmospheric) pressure. Figure 1 graphically shows the relationship between reported levels of TDG supersaturation (relative to surface pressure) and the true level of supersaturation experienced by fish at various near-surface depths. The compensation rate is about 10% of saturation or 74 mm Hg per meter of depth(Don.E.Weitkamp Ph.D., 2008).

Gas bubble disease

Gas bubble disease(GBD) can result when the water is supersaturated with gas (bottom of a waterfall or overactive aquarium aerator).Both oxygen and nitrogen enter the fish via the gills, where it is rapidly distributed bia the bloodstream to the tissues. At this time, supersaturated gases come out of solution and form gas bubbles, thus leading to the condition known as GBD. Unfortunately, many cases of GBD do not present specific clinical or pathological changes(Point Four System Inc., 2005)

The main symptoms are: Bubbles visible in the lateral line, gill filaments, gill covers and fins Exophthalmia (bulging eyes) No visible signs Result in: Damage to blood capillaries Impaired organ development and function, particularly in relation to the gills An increased susceptibility to disease Behavioural effects(more vulnerable to predation)

Safe level limits

In natural circumstances, the limit of safe gas supersaturation levels depends on the escape depth available and species behavior, but this limit usually occurs between 105% and 120% of equilibrium total gas saturation pressure (ambient atmospheric pressure). Under captive conditions, the total dissolved gas pressure should be as close to 100% as possible. For sensitive species and life stages, sublethal and lethal effects of Gas Bubble Disease have been observed at total dissolved gas pressures as low as 101%(G. Carlson and T. krikbride, 2005).Result

Total dissolved gas (TDG) supersaturation is a unique parameter in the water quality regulation. There is still no research in Korea. It was started in 1960s in the Columbia River system when TDG or nitrogen supersaturation was identified as potential threat to fish and other aquatic resources downstreams from dams(D.E. Weitkamp Ph.D., 2008). Currently, they are monitoring in many dams: Project names are Bonnebille, The Dalles, John Day, McNary, Ice Harbor, Little Goose etc. (L. Hamilton, 2008). That is a field completely unfamiliar to Korean researchers. We found a high TGP supersaturation in August, 2008 in the Soyang River(Table 1), but we found no direct observation of gas bubble disease of fish yet, because the area is not inhabited by fish.. However, the study of TGP will be necessary in monitoring of the Soyang River because it is one of the serious problems in aquatic ecosystem. Reference

Hamilton, L.. 2008. History of the total dissolved gas monitoring system. Corps of engineers, NWDPoint Four Systems Inc. 2005. Total gas pressure information sheet.Watten, B.J. and D.R. Smith. 1997. Continuous monitoring of dissolved oxygen and total dissolved gas pressure based on head-space partial pressure. journal of the World Aquaculture Society. Vol. 28, No. 4.Weitkamp, D. E., R. D. Sullivan, T. Swant, and J. DosSantos. 2003a. Behavior of Resident Fish Relative to TDG Supersaturation in the Lower Clark Fork River. Transactions of the American Fisheries Society 132: 856-864.Weitkamp Ph. D., D.E. 2008. Total dissolved gas supersaturation biological effects, review of literature 1980-2007. Carlson, G and T. kirkbride. 2005. Supersaturation and gas bubble disease why measure total dissolved gas?. InSitu Inc. Technical note 17.

Table 1. TGP, N2, O2, PN2, PO2, in the discharge water of the Soyang DamDateTimeWeatherTGP(%)N2(%)O2(%)PN2PO2

2008.08.2713:30Sunny11111985105-23

2008.08.2717:45Sunny11111889100-17

2008.08.281:04Sunny11712395130-7

2008.08.2815:30Sunny114117105937

2008.08.290:58Sunny11411899101-1

2008.08.3115:12Sunny1131179993-2

2008.09.011:40Sunny1131179997-1

2008.09.0115:13Rainy1091158983-17

2008.09.0123:19Rainy1091149081-15

2008.09.028:40Cloudy1081109859-3

2008.09.0213:20Cloudy111115101842

The 8th Joint Symposium of Kangwon National University and Tottori University on Environmental Science and Technology. 11-13 October 2010..

Export of Phosphorus and Nitrogen from Agricultural River Basins in Korea

Jaesung EUM*, Bomchul KIM Department of Environmental Science, Kangwon University, Chuncheon city, Korea.*E-mail: [email protected]

Abstract

We investigated transport of phosphorus and nitrogen in agricultural river basins was measured over a period of 1 year (May 2009-May 2010). The basins were typical of agricultural land use (about 35% of total basin area) in the Korea. The crop mainly was vegetables (potato, radish, Chinese cabbage). During rainy season, flow weighted total phosphorus (TP) averaged 1.043 mg/L. It was 18 times higher than TP of dry season (0.057 mg/L). On the contrary, flow weighted total nitrogen concentration averaged 2.271 mg/L during rainy. It was 2 times lower than TN of dry season (5.092 mg/L). The low concentration of TN in rainy season may be due to dilution by precipitation. More than 83% of TP was consist of particulate phosphorus (PP) in rainy season. Most of the nitrogen export was in the dissolved form all season. More than 85% of TN was nitrate and ammonia was less than 1%. Specific areal loading from agricultural river basin for TP, TN was 9.2, 21.3, kghayr-1, respectively. The specific areal loading from agricultural basin was much higher than other agricultural area. In the next phase of this study, these results will be used to validate a watershed ecosystem model to quantify nutrient and hydrologic fluxes.

Keywords: total phosphorus, total nitrogen, specific areal loading

1. Introduction

Phosphorus and nitrogen losses from agricultural soils to water can pose a threat to water quality. High phosphorus and nitrogen inputs in chemical fertilizers and organic manure to agricultural soils can exceed crop requirements. This practice often results in excessive phosphorus and nitrogen accumulation in the soil, and such soils represent a potential nonpoint source of pollution as an important role in the eutrophication of surface waters and lake. Control of phosphorus and nitrogen in drainage water is usually recommended as the best way to minimize the eutrophication process. Most of agricultural land is consist of upland (48%) which is cultivated in high slope in Haean catchment. Sloping uplands can cause severe soil erosion during rainy season. For that reason, farmers input the dressed soil that consists of sandy loam in every year. One of the main reasons for application of the dressed soil in agricultural land is to prevent failure by monocropping and increase crop productivity thereby developing better drainage. However, the dressed soil has a negative effect on soil erosion with water contamination.In this study, we investigated stream discharge and phosphorus and nitrogen in rain event from agricultural river basin with various crops and slopes.

2. Method and materials

Water samples were collected at 7 sampling sites of the Haean catchment for 4 rain events in 2009. Phosphorus in all stream were determined by the colorimetric molybdenum-blue method of APHA (1998). Particulate phosphorus was calculated as the difference between TP and total dissolved phosphorus.

Fig. 1. Map of the sampling sites of the Mandae stream.

Fig. 2 Land use of the subcatchments.

Fig. 3. The crops of in cultivated in catchment.

3. Results

Fig. 4. The comparison of FWMC (flow weighted mean concentration) in rainy season with dry season.

Fig. 5. Spatial distribution of areal loading of TN and TP.Table 1. The comparison of export coefficient for TP and TP.WatershedLand useTN TP Ref.

EPA, USA mixed agricultural 16.51.13Reckhow et al.(1980)

forested2.860.24

urban9.971.91

USA and Europe forest1.0~6.30.007~0.88Loehr et al.(1989)

Rural cropland21~79.6 0.06~2.90

Wisconsin, USA agricultural6.690.26Clesceri et al.(1986)

forest4.070.176

Eastern, USA. forest30.05~0.10Rast and Lee (1978)

agricultural50.5

Mandaeagricultural - forest16.514.482003

67.948.592004

9.221.32009

4. Summary

1. During storm event, export of phosphorus and nitrogen were in particular form (about 97%)

2. Spatial variations of FWMC for nitrogen and phosphorus was very large

3. During storm event, FWMC of Phosphorus were about 10 times higher than dry season

4. Annual areal loadings of phosphorus were much higher than other studies (10~100times)

5. It is evident that more research is needed to characterize of the nonpoint N, P load from agricultural catchments.

6. Even if this research was conducted for 1yr, it could be useful to validate on simulation hydrologic or ecosystem model.


The Analysis of the Effect of Land Use and Forest Physiognomy on the Stream Water

Heewon NAM, Bomchul KIMDepartment of Environment Science, Kangwon National University, Kangwon-do, Korea.*E-mail: [email protected]

Abstract

Land use there is relationship which is close with the water quality of the rivers. The effect of land use according to exhaust time and exhaust space is a characteristics which changes independently to about the water quality of the rivers. The ostensible outflow in compliance with the rainfall the contaminant movement is because in the rivers, the land use of the cultivation area is affecting the nitrogen and phosphorus. But, the forest area did the duty which decreases the contaminant. It showed a big difference in the water quality which from the forest area it follows in type of the forest. It excepted NO3-N and all parameters of water quality showed the negative correlation of the forest.

Keywords:

Land Use, Water Quality, Exhaust time and space, Rainfall, Forest area

1. Introduction

With result of growing population and industrial advancement etc. the many contaminant occurs from the watershed and the effect which is big in the water quality of the rivers and reservoirs. The effect of land use according to exhaust time and exhaust space is a characteristics which changes independently to about the water quality of the rivers, (Allan et al., 1997; Townsend et al., 2003). Tong and Chen (2002) said that there is relationship with land use of the residential area and the business area, the agricultural area and the nitrogen and phosphorus concentration, announced. Brainwood et al., (2004) announced that there is high relationship phosphorus case with residential areas and NO3 with land use of grassland. Also the watershed of agriculture made make as the nutrition salt or considerably flows out many sediment. (Kimmel et al., 1990; Knowlton and Jones, 1995; Knowlton and Jones, 2000).Data of water quality use that is calculated discharge loading as accumulation of huge data national population, livestock, industry, land, sewage disposal plant etc., it is caused by recently with introduction of total maximum daily loads (TMDL) (choi et al., 2004), but it is a condition where the part which still it will improve is considerable.This study which it sees 133 important rivers of the entire country executed a correlation analysis to about it affects in the water quality of rivers which in the object it follows in land use and pollutant source. With data of this study which it sees it could be used with fundamental data of the management where the analytical result land use and contaminated source is effective.

2. Method and materials

This study carries out analysis about rivers 133 of the entire country managed by from Water Information System (WIS). The land use classified with the waters as city, paddy field, field, forest, grassland, wetland, watershed used by data of Water Management Information System (WAMIS).The watershed is 43.87~2783.26 km2 with feature of the basin, the average watershed is 507.11 km2. The forest above 65% of the watershed as typical non-city type agrees with the area ratio of the forest with national ratio. The cultivation area with average 24%, the paddy field area average 18%, the field area it corresponds to an average 6%. The case conifer of the forest average 27%, the broad-leafed tree the average 17% mixed-tree it corresponds to an average 17%.The parameter of water quality used water quality of BOD, SS, TN, TP, NO3-N and Chlorophyll-a until of 2004 January 2005 December. BOD average 2.63 mg/L and SS 8.9 mg/L and TN 3.636 mg/L and TP 0.140 mg/L and Chlorophyll-a 6.1 mg/m3 is the water quality standard level which corresponds to 2 grade of BOD and 1 grade of SS.Correlation analysis carry out that used the collected data by SPSS of statistical program (Ver. 18). The higher officer analysis measures the degree of relationship between variable and it expresses it is an analysis. The correlation analysis used multiple regression and it showed it was it recognized the higher officer degree of land use and parameter of water quality and between within level of significance 5% and the interrelation of usual, the case which will be bigger 5% than judged that the interrelation is not formed.

3. Result

It respects the standardization of parameter of water quality Log it did in parameter of water quality. It had this, result NO3, which accomplishes stepwise multiple regression of parameter of water quality and land use, showed positive correlation with grassland, the different parameter of water quality showed the negative correlation with forest in all season.

Table 1. Stepwise multiple regression between water quality and land useStepParameterEstimatepRR2

LogBOD

Intercept0.912

1Forest(%)-1.1280.0000.6520.425

LogSS

Intercept1.642

1Forest(%)-1.5300.0000.5940.353

2City(%)-0.8330.0280.6130.376

LogTN

Intercept0.635

1Bare(%)5.2870.0000.4960.246

2Forest(%)-0.3940.0000.5470.299

LogTP

Intercept-0.154

1Forest(%)-1.7280.0000.6570.431

LogNO3-N

Intercept0.181

1Grassland(%)1.7030.0150.2250.050

LogChlorophyll-a

Intercept1.022

1Forest(%)-0.9700.0000.4580.210

2Grassland(%)-3.2980.0100.5260.217

3Water(%)3.4310.0040.5680.323

4Field(%)1.4960.0330.5880.346

Table 2. Stepwise multiple regression between water quality and forest physiognomyStepParameterEstimatepRR2

LogBOD

Intercept0.912

1Conifer(%)-1.2460.0000.4360.190

2Mixed-tree(%)-1.3430.0000.5590.312

3Broad-leaved tree(%)-1.0220.0000.6550.429

LogSS

Intercept1.412

1Conifer(%)-1.2600.0000.4300.120

2Mixed-tree(%)-1.5410.0000.5450.222


LogTN

Intercept0.828

1Conifer(%)-0.7020.0000.3180.101


3Mixed-tree(%)-0.6020.0050.4470.199

LogTP

Intercept-0.180

1Conifer(%)-1.8740.0000.4300.184

2Mixed-tree(%)-1.9670.0000.5450.297


LogChlorophyll-a

Intercept1.007

1Mixed-tree(%)-1.1660.0000.2810.079


3Conifer(%)-0.8120.0000.4850.236

Accomplishes multiple regression with forest physiognomy, the result, NO3 is no relationship with forest physiognomy because NO3 isnt related with the forest.Also with R2 of the forest similar aspect it seemed with 3 level of forest physiognomy, it showed the all negative correlation. BOD showed order of multiple regression with conifer, mixed-tree and broad-leaved tree, like this SS and TP degrees it showed an order, TN showed order of multiple regression with conifer and broad-leaved tree, with mixed-tree Chlorophyll showed order of multiple regression with mixed-tree and broad-leaved tree, appeared with conifer.

4. Conclusion

Forest of the above 65% of the country is high relationship with parameter of water, also it showed the negative correlation, it is the recording the many forest and the better improve water quality. There is little difference or not, but excepted NO3, forest is high relationship with water quality improvement. Like this resultant forest affects in the water quality as affirmation it will be able to judge very.

5. Reference

Allan, J.D., D.L. Erickson and J. Fay. 1997. The influence of catchment land use on stream integrity across multiple spatial scale. Freshwater Biology 37:149-161Brainwood, M.A., S. Burign and B. Maheshwari. 2004. Temporal variations in water quality of farm dams: impacts of land use and water sources. AgriculturalwaterManagement 70:151-175Kimmel, B.L., O.T. Lind, and L.J. Paulson. 1990. Reservoir primary production, pp. 133-193. InK.W.Thornton,B.L.Kimmel,andF.E.Payne(eds.),Reservoirlimnology:Ecologicalperspectives.Wiley.Knowlton, M.F., and J.R. Jones. 1995. Temporal and spatial dynamics of suspended sediment, nutrients, and algal biomass in Mark Twain Lake, Missouri. Arch. Hydrobiol. 135: 145-178.Knowlton, M.F., and J.R. Jones. 2000. Non-algal seston, light, nutrients and chlorophyll in Missouri reservoirs. Lake Reserv. Manag. 16: 322-332Tong, S.T.Y. and W. Chen. 2002, Modeling the relationship between land and surface water quality.J.Environ.Manage.66(4):377-393Townsend, C.R., S. Doledec, R. Norris, K. Peacock, C.J. Arbuckle. 2003. The influence of scale and geography on relationships between stream community composition and landscape variables: description and prediction. Freshwater Biology. FunctionalEcology3:385-397., , , , (2004). (1)- , , , pp. 19


Estimation of Collection and Transport Costs of Johkasou Sludge in Tottori Prefecture.

Tatsuya KONDODepartment of Social Systems Engineering, Tottori University, Japan.E-mail:[email protected]

1. IntroductionDomestic wastewater discharged by 1150 million people is treated by treatment facilities and it is 90% of the total population in Japan. 29million people use Johkasou to treat wastewater. There are 6 night soil treatment plants in Tottori prefecture. Almost all of the Johkasou sludge is transported to the night soil treatment plants. Night soils are collected by each Municipality. Night soil treatment plants disposed of 85,000 kiloliter sludge in 2008.The Johkasou is individual sewage treatment equipment to treat wastewater. The Johkasou is used in area where sewage system is not constructed.Organic pollutants are decomposed by microbe and treated water is disinfected and discharged into river. Sludge product through treatment accumulates in the tank of Johkasou. Therefore, the Johkasou owner has to do inspection, cleaning and other maintenance regularly.Sewage systems are developed in big cities. Johkasou are used in mainly small cities. Sewer systems need sewage pipelines. Long sewage pipeline person is needed in the sparsely populated areas like small towns and villages. As most of sludge of Johkasou is collected and transported by private companies, its cost has not been published. It is also difficult to find the actual situation of Johkasou maintenance, because it is carried out by each owner. The Johkasou sludge is treated in the night soil treatment plants with collected night soil. Therefore, the Johkasou sludge treatment cost is not accounted being separated from night soil. The amount of the Johkasou sludge will decrease due to population decrease. It affects on cost efficiency of sludge collection and treatment. In order to investigate effective management of the Johkasou sludge treatment, current cost structure of the sludge treatment should be investigated. In this study, management of Johkasou is considered. First, current situation of the Johkasou sludge treatment is examined. Next, cost analysis of the Johkasou sludge under the condition of population decrease is carried out. On the basis of those results, effective system of the future treatment of Johkasou sludge including the treatment plants relocation is considered.

2. Methods The number of Johkasou is counted with the list of the registered Johkasou in Tottori prefecture. Items of the list are the name of town where Johkasou is equipped and type of Johkasou, and so on. Johkasous were classified according to the town and type. They are displayed on the map with GIS.

3. ResultAbout 31000 Johkasous are registered in Tottori prefecture. There are about 11000 Gappei-shori Johkasous which treat night soil and domestic wastewater and about 20000 Tandoku- shori Johkasous which treat night soil only in March 2010 in Tottori prefecture. Number of Johkasou in each grid cell is obtained. It is shown in Figure1.

(km) Figure1. Number of Johkasous in Tottori

There are a lot of Johkasous in city areas on Tottori prefecture. It shows there are areas where sewer systems are not developed in city areas. Night soil treatment plants and relay plants are displayed by Address Matching method of GIS. Address Matching is function which each point is identified on the map with its address. Collective points put on the center of every gird cell. Collective Points are shown in Figure2.

Figure2. Collective area in eastern Tottori

Eastern area of Tottori prefecture has one night soil treatment plant and 7 relay plants, central and western areas have 5 plants. Johkasou sludge is transported from collective point to night soil treatment plant or relay plant. Network Analyst is displayed the shortest route of sludge transportation on the map from collective point to night soil plants. Road of the shortest route shown in Figure3.

Figure3. The shortest root of collective sludge

The collective distance is calculated the road distance which is displayed on map. The collective cost is calculated with collective distance and amount of the Johkasou. 4. Future subjectThe amount of the Johkasou sludge grid cell will be calculated in order to calculate collection sludge cost. Night soil treatment plants cost will be investigate. The actual cost of Johkasou sludge treatment will be estimated. Future Johkasou treatment cost will be examined the change amount of Johkasou sludge in population decrease. Night soil treatment plants will be considered life span and relocation.

Reference Johkasou list in Tottori prefecture (2010.3) Ministry of the Environment(2008) : result counted treatment night soil in Japan Ministry of the Environment(2008) : result counted treatment night soil in Tottori prefecture]


Effect of Clear Water Bypass Operation on the Water Quality in a Reservoir

Jungkyu CHOI* and Hiroshi YAJIMA Dept. of Manage. of Social Systems and Civil Eng, Tottori University, Tottori city, Japan.*E-mail: [email protected]

AbstractMany reservoirs have difficulties in their management due to water quality problems. The aim of this research is to compare the reservoir water quality change caused by a bypass operation. Urayama Dam has a bypass tunnel facility that enables the reservoir to directly discharge clear water from upstream from during the non-flood season. It is possible to improve the water quality downstream by using the bypass, but the study to evaluate the influence inside the reservoir has not been conducted. Therefore using ELCOM-CAEDYM model, 3 scenario simulations has been done for this evaluation. First scenario is the simulation with the actual bypass operation in 2009 (scenario 1), second one is the simulation without bypass operation (scenario 2) and third one is the simulation with maximum discharge operation by the bypass tunnel (scenario 3). The model results showed small differences between the scenario 1 and 3. But the results of scenario 2 were much different from others and especially SS concentration showed high concentration comparing with scenario 1 and 3. Scenario 2 is the highest inflow amount in scenario because of the without bypass operation.

Keywords: Clear water bypass, ELCOM-CAEDYM model, water quality management

1. IntroductionAlgal bloom and turbid flow are both major water quality issues for the management of lakes and reservoirs in Japan. In addition, it is expected that the frequency and strength of algal bloom and turbidity will increase with the global warming in the future because of increased temperature, runoff, nutrient load, and enhanced biological metabolism. In order to confront effectively with the reservoir water quality problems, various facilities for water conservation such as selective withdrawal system, curtain weir, aerator system and bypass facilities has been already established and some reservoirs has installed more than two facilities. Asahi Dam installed a turbid water bypass tunnel for the first time in Japan, and it helps to restore the downstream environment as well as to reduce the turbid water problem. The turbidity in the reservoir was found fairly low compared with that of before the operation and it was also found that sedimentation became 1/10 compared with the before the operation. The same system in Miwa Dam also showed similar effectiveness. Urayama Dam at the non-flood clean water to discharge directly to downstream was used. The study area is located in Arakawa river basin, Saitama prefecture, Japan. Urayama Dam was completed in 1999 and has a watershed of 51.6 km2 and an effective storage of 58106 m3. The reservoir is considered as one of the most important water resources since it supplies 350,000 m of drinking water per day and also used for flood control, irrigation, and hydropower generation.

2. Method and materials The ELCOM (Estuary, Lake and Costal Ocean model) developed by CWR (Centre for Water Research), is a three-dimensional, hydrodynamic model. The CAEDYM (Computational Aquatic Ecosystem DYnamic Model) also developed by CWR is a water quality and ecosystem model. Coupled these two models is applied to Urayama Dam.The model domain of Urayama Dam was discretized into a x=y=100m in the horizontal direction, and z=1.0m in the vertical direction, forming 7,299 computational cells. ELCOM requires wind speed and direction, air temperature, relative humidity, solar radiation, and cloud cover.CAEDYM requires water quality and relative parameters (configuration, initial, sediment, chemistry, biological).Table 1 showed scenario of model application. Scenario 1 is the actual bypass operation condition in 2009, scenario2 is without bypass operation condition and scenario 3 is the maximum discharge operation through the bypass tunnel.

Table 1. Scenario for the model applicationScenario #bypass discharge

# 1currently operation(2009)

# 2without bypass

# 3maximum discharge

3. ResultThe performance of the ELCOM-CAEDYM model for the simulation of water temperature, SS, Chl.a, TN and TP was validated by comparisons of the observed and simulated data at the monitoring station in front of the dam wall in 2009 (Figure 1). Overall the model well reproduced the temporal changes of stratification structure, SS profile and other water quality in the reservoir.

(a) temperature(b) SS

(c) Chl.a, TN, TP

Figure 1. Comparison of simulated (line) and observed (circle) data

The temporal variation of water quality at the monitoring station for applied scenarios was presented in Figure 2. Water temperature profiles showed a similar pattern for all scenarios. But scenario 3 water temperature was a little lower simulated after September. Scenario 2 results showed very different profiles of SS. They showed high concentration after flood than that of scenario 1 and 3. This is because scenario 2 has the highest inflow amount and much resuspension occurred for this scenario. Chl.a and TN showed a similar pattern for all scenarios. TP concentration was the highest for scenario 2.The water quality for the total outflow is presented in Figure 3. Scenario 2 was estimated highest water temperature, SS and TP for the total outflow. Chl,a and TN showed a similar pattern for all scenarios.

(a) temperature(b) SS

(c) Chl.a, TN, TP

Figure 2. Simulated profiles (a, b) and time series(c) of concentration according to scenarios in 2009

Figure 3. Simulated time series of outflow water quality according to scenarios in 2009

4. ConclusionIn this study, we characterized the variation of water quality due to the bypass operation at Urayama Dam. The model showed good performance in reproducing the water temperature profiles, SS profiles, Chl.a, TN and TP at surface within the acceptable errors. Moreover the SS and TP both in reservoir and outflow were higher in the order of scenarios 2, 1and 3. Scenario 2 has the highest inflow amount among the scenarios because of the without bypass operation. So x-velocity was higher to dam direction and reduce the natural settling time for SS.


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