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Sewage treatment can remove more than 90% of microplastics, yet large amounts of microplastics are discharged into the ocean. Because microfibers (MFs), primarily generated from the washing of synthetic clothes, are the most abundant type of microplastics among various microplastics detected in the sewage treatment, reducing the amount of MFs entering these treatment plants is necessary. This study aimed to test whether the amount of MFs released from the washing process can be reduced by applying a chitosan pretreatment to the garments before washing. Before the chitosan pretreatment, the polyester clothes released 148 MFs/L, whereas 95% of MFs were reduced after the chitosan pretreatment with 0.7% of chitosan solution. The chitosan pretreatment was applied to other types of garments, such as polyamide and acrylic garments, by treating them with 0.7% of chitosan solution, subsequently, MFs reduced by 48% and 49%, respectively. A morphology analysis conducted after washing revealed that chitosan coating on the polyamide and acrylic were more damaged than on polyester, suggesting that the binding strength of polyamide and acrylic with chitosan was weaker than that of polyester garment. Thus, the results suggested that the chitosan pretreatment might be a promising solution for reducing the amount of MFs generated in the laundering process.

The object of this research is to analyze the water quality improvement of Lake Paldang by implementing Integrated Lake Basin Management (ILBM). To establish ILBM, the basin environment database was built as well as water environment management support system for monitoring present conditions, and predicting changes in basin environment. The major contaminants in Lake Paldang Basin are from domestic pollution, agricultural land, and livestock. Scenarios for reducing contaminants were targeting the increase percentage of sewered population, agricultural and livestock contaminants reduction to analyze the water quality improvement effects. This study applied the SWAT model to Lake Paldang Basin using the basin environment database to improve the water quality of Lake Paldang in Korea. The results of calibration and validation of flow rate, Suspended Solids (SS), Total Nitrogen (TN) and Total Phosphorus (TP) showed that the measurement values and simulation values turned out to be similar, and that it is possible to apply the SWAT model to Lake Paldang Basin. The reduction efficiency of SS by scenario was 11-45%, TN 8-37%, and TP 7-35% and this shows that water quality was significantly improved prior to application. Therefore, to improve the water quality of Lake Paldang, it is recommended to implement the ILBM which is considered to play an important role in making water quality management policy in Korea.

When phosphorus and nitrogen concentrations are high in lakes and reservoirs, enough for algae to grow, algal bloom prevention needs to be approached by circulation of stagnant water. A new circulation technology ‘Spiral vortex artificial circulation’ was developed that transports water to the surface without any hose and also provides sufficient oxygen as the water circulates. Artificial thermal and dissolved oxygen stratification was created in a water tank, and thermometers and DO meters were placed at each layer to evaluate the technology’s efficiency by comparing how fast the stratification broke. Two types of booster were used: a flow booster which promotes thorough mixing and a 12 cm flat round booster that protects the bottom of water column from disturbing, yet circulates the surface. Impeller speed was set at 60 rpm and 180 rpm to compare speed difference thus total of four experiments were conducted. The stratified water was completely mixed in two experiments with flow booster. However when 12 cm flat round booster was used at 60 rpm, even after 100 minutes of operation the stratification was not broken whereas it took 75 minutes at 180 rpm. The same or similar settings can be applied in situ without disturbing the benthic zone; if not, nutrients could be released to water bodies which might lead serious eutrophication. The further technology evaluation is in progress for improving its algal bloom suppression and energy efficiency since all technologies required to be environmentally sustainable.

The algae bloom in river has been issued in Korea. In order to alleviate treatment load of water treatment plant and to meet water treatment capacity of the plant, a high-speed algae pretreatment methods connected with water intake pipe are required. In this study, a pilot-scale of pretreatment system was tested. It was consisted of coagulation and electro flotation processes. The algae pretreatment efficiency by the comparisons of chlorophyll-a, nutrients (total nitrogen, total phosphorous), and chemical oxygen demand (COD) concentration was evaluated. As a result, the system showed about 45% of removal efficiency by the only flotation separation without coagulation judged by chlorophyll-a concentration. On the other hand, the removal efficiency was improved with increase of coagulant dosage and electric power. It was improved to about 80% of chlorophyll-a concentration. The system could treat algae containing solution within a few minutes on the basis of residence time of flotation tank. Consequently, this study suggests that the system could be used as an algae pretreatment step in water treatment process.

The first flush of rainwater in urban areas is highly contaminated and causes adverse effects on both the water environment and ecosystem. In this study, a novel filtration device using expanded polypropylene media (EPM) was developed for efficient control of pollutants in first flush of urban runoff. The effect of foaming ratio on EPM for filtration efficiency and clogging potential was examined under various operating conditions. Experimental results using a laboratory-scale filtration device indicated that the removal efficiencies of suspended solids were initially high (>90% removal until 60 minutes) and decreased with filtration time (60% for EPM15 at 180 minutes and less than 10% for EPM45). Similarly, more than 90% of Cr, Pb, and Zn were removed for EPM15 within 30 minutes and decreased with filtration time. The surface area and specific hydraulic resistance of EPM were sensitive to foaming ratio. Optimum conditions for foaming ratio increased pollutant removal and minimized head loss. A simple model was derived and applied for theoretical analysis of the filtration device with EPM.

Recently, environmental pollution from microplastics (MPs) has become a significant reason for increasing the number of studies to develop analysis methods. The Nile red staining method (NR-S), which is staining polymer particles with Nile red (NR) dye, has been widely used for the analysis of MPs in environmental samples. However, this method has several limitations, as it is difficult to stain MPs covered with organic matter residues. In this study, we modified the NR-S method into an NR plate method (NR-P), where the plate is coated with NR instead of staining MPs directly. The optimum concentration of NR solution was obtained (1000 mg/L), and the effectiveness of the NR-P method for the analysis of MPs was assessed using different types (polypropylene, polyethylene, polyethylene terephthalate, and polystyrene), sizes (100&ndash, 1000 &micro, m), and shapes (sphere, fiber, film, and flake) of plastic materials. The NR-P method demonstrated improved resolution in the overall types, shapes, and sizes of MPs and was better than the control (without NR plate method) and NR-S method. In particular, the NR-P method can effectively observe MPs covered with organic matter, which was a major limitation of the NR-S method. Finally, MPs in sewage field samples were analyzed by the NR-P method with an accuracy of 78% confirmed by FT-IR. We demonstrated that this method is a convenient and efficient alternative for identifying MPs, even for field samples.

A biofilm filtration for the removal of gaseous pollutants has been recognized as a process with a complex interaction between the gas flow characteristics and the process operating variables. This study aims to develop an one dimensional dynamic numerical model which can be utilized as a tool for the analysis of biofilm filtration process operated in plug flow mode. Since, in a plug flow system, minor environmental changes in a gaseous unit process cause a drastic change in reaction and the interaction between the pollutants is an influencing factor, plug flow system was generalized in developing the model. For facilitation of the model development, dispersion was simplified based on the principles of material balance. Several reactions such as competition, escalation, and control between the pollutants were included in the model. The applicability of the developed model was evaluated by taking the calibration and verification steps on the experimental data performed for the removal of BTX at both low and high flow concentration. The model demonstrated a correlation coefficient () greater than 0.79 under all the experimental conditions except for the case of toluene at high flow condition, which suggested that this model could be used for the generalized gaseous biofilm plug flow filtration system. In addition, this model could be a useful tool in analyzing the design parameters and evaluating process efficiency of the experiments with substantial amount of complexity and diversity.

Cyanobacteria frequently dominate the freshwater phytoplankton community in eutrophic waters. Cyanotoxins can be classified according to toxicity as neurotoxin (Anatoxin-a, Anatoxin-a(s), Saxitoxins) or hepatotoxin (microcystins, nodularin, cylindrospermopsin). Microcystins are present within cyanobacterial cells generally, and they are extracted by the damage of cell membrane. It has been reported that cyanotoxins caused adverse effects and they are acculmulated in aquatic oganisms of lake, river and ocean. In natural, microcystins are removed by biodegradation of microorganisms and/or feeding of predators. However, in process of water treatment, the use of copper sulfate to remove algal cells caused extraction of a mess of microcystins. Microcysitns are removed by physical, chemical and biological methods according to reports. The reduction of nutrients (N and P) inflow is basic method of prevention of cyanobacteria bloom formation. However, it is less effective than investigation because nutrients already present in the eutrophic lake. In natural lake, cyanobacteria bloom are not formed because macrophytes invade from coastal lake by eutrophication. Therefore, a coastal lake has to recover to prevent of cyanobacteria bloom formation.

Electro-coagulation experiments were conducted with aluminum (Al) or iron (Fe) electrode in order to determine the optimal electrode material and operation conditions for algae removal. Al electrode showed higher removal rate of algae than Fe electrode because Al flocs have positive surface charges which electrostatically attract algae species having negative surface charges. Removal rate of algae and total phosphorous (T-P) was increased as current density and electrode area increases. It was also found that initial pH with neutral range was optimum for T-P removal by electro-coagulation. Bench-scale continuous flow experiments consisted of electro-coagulation reactor, agitation tank and settling tank were conducted. In electro-coagulation reactor, a large fraction of Al flocs were distributed to scum layer, due to the gas bubbles generated by electrolysis reaction. In agitation tank, most of Al flocs were settled and the optimal mixing intensity was found to be 50 rpm to achieve good settleability. The removal rate of algae was about 90-95%. Additionally, the removal rate of the T-P and COD was observed to be 73.8±8.0% and 75.0±3.8%, respectively. Meanwhile, the removal rate of total nitrogen (T-N) was relatively low at only 24%.

Cavitation generated by ultrasonic irradiation can enhance the diffusional transport of organic contaminants from soilsurfaces or pores. Therefore, ultrasound soil washing can be an alternative of traditional soil washing process. In this study,soil was artificially contaminated with n-tetradecane, n-hexadecane and phenanthrene. A plate type ultrasonic reactor at25 kHz frequency and 1000 W power was used for laboratory soil washing experiments. Ultrasonic soil washingefficiency was compared with those of traditional soil washing using mechanical mixing. Various operational parametersuch as soil/liquid ratio, irradiation time, particle size, and soil organic matter content was tested to find out the optimumcondition. It was found that ultrasonic soil washing demonstrates better performance than mechanical soil washing.Optimum soil:liquid ratio for ultrasonic soil washing was 1 : 5. Desorption of organic contaminants from soils by ultrasonicirradiation was relatively fast and reached equilibrium within 10 minute. However, decrease in the soil particle sizes byultrasonic irradiation results in re-adsorption of contaminants to soil phase. It was also observed that soil particle sizedistribution and soil organic matter content have significant effects on the efficiency of ultrasonic soil washing. Key words :Ultrasound, Desorption, Soil Washing, Soil organic matter, Particle size distribution

A three-dimensional ocean circulation model was applied to a shallow estuary, Mobile Bay, to study local wind setup and setdown. Tides started from the northern Gulf of Mexico propagates up to the Mobile River system which is located in the north of the Mobile Bay. However, the tides started in the south of Mobile Bay were distorted when travelling upstream while affected by river discharge and local winds. The water surface elevation was less/over predicted responding north/south winds, respectively, when winds only at the Dauphin Island station (DPI) were used. However, the model predicted water surface elevation better when using two local winds from DPI and Mobile Downtown Airport (MDA). Wind speeds were greatly reduced (~ 88%) in about 43 km distance between DPI and MDA, and the canopy effects may be the reason for this. For this reason, the local winds are greatly responsible for local surface elevation setup and setdown especially at the shallow estuary like Mobile Bay.

The object of this study was to evaluate the combined toxic interactions of the perfluorooctanoic acid (PFOA) or perfluorooctane sulfonate (PFOS) with six heavy metals (Cu, Zn, Cr, Cd, Hg, and Pb). The individual and combined toxic effects were assessed using the Vibrio fischeri assay. In case of the individual toxicity, PFOA was higher toxic than PFOS and toxicity of PFOA and PFOS were lower than heavy metal. In the toxicity of heavy metals, the was found to be most toxic followed by , , , , and . The combined toxicity of PFOA or PFOS with were synergistic effect because the mix values were less than 1 TU. PFOA + , PFOS + , PFOA + and PFOS + produced addictive effect. Except in these case, all of binary mixtures show antagonistic effect. This study proved potential risk of coexistent with perfluorinated compounds and heavy metals in water environment.

This study explores membrane distillation (MD) is suitable to recover pure water and to generate the supersaturation condition for the crystal formation. The system was carried out under a different temperature of feed solution. It was observed that the increase in the mass flux of product solution is due to the increase in the temperature difference between the feed and product solution. Although the temperature difference is important for the mass flux of product solution, it needs to consider a reasonable temperature difference. The highest rejection (%) was observed at feed temperature 60°C and it is easy to control. It was found that both surface crystallization and bulk crystallization influenced the flux decline of MD. Calcium sulfate crystals can be produced by MD crystallization with a growing crystal size distribution and average size of 100 μm.

The high-speed algae pretreatment system consisted of coagulation and electro coagulation process was tested. This study examined algae removal efficiency by the comparison of chlorophyll-a concentration before and after treatment. As a result, the system showed about 45% of removal efficiency by the only flotation separation without coagulation. As increase of electric power and coagulant dosage, the removal efficiency was improved to about 80%. The system could treat algae containing solution with a few minutes on the basis of residence time of flotation tank. Consequently, this study suggests that the system could be used as a pretreatment step in water treatment process.

The field study was carried out to investigate runoff characteristics of non-point source (NPS) by cultivation activity in river district. Two sites were selected mainly as G region (paddy field, green house), located in Kwangju, Gyeonggi Province, and S region (ordinary field), located in Namyangju, Gyeonggi Province, those belong to Paldang reservoir watershed. The paddy field with water storage capacity showed a slow increase in runoff as rainfall intensity increases. Meanwhile, both green house and ordinary filed revealed a rapid increase. The average BOD runoff concentration of paddy field, green house, and ordinary field was 2.0 mg/L, 2.8 mg/L, 7.9 mg/L, respectively. It indicates that ordinary field shows the highest value in BOD, SS, T-N, and T-P concentration due to the soil loss during rainfall. As a result of runoff load estimation according to the field, a T-N runoff load of paddy field was 1,793.9 kg/year, higher than that of ordinary field. It was estimated that a SS runoff load of ordinary field was 69,704 kg/year and accounts for more than 70% of overall runoff load.

The degradation of 30 pharmaceuticals and personal care products (PPCPs) subjected to O3, O3/UV, and O3/H2O2 treatments were investigated using semi-batch tests and evaluated by their pseudo-first-order rate constants. The additional application of UV or H 2 O 2 during O3 treatment significantly improved the degradation rate of most of the PPCPs. At the same O 3 feed rate, O3/UV treatment exhibited much higher PPCP degradation efficiency than that of O 3 treatment. This was probably due to degradation of the PPCPs by O3, direct UV photodegradation, and OH radicals that formed from the photodegradation of O3 during O3/UV treatment. PPCP degradation by O 3 was also promoted by adding H 2 O 2 during the O 3 treatment. However, when the initial H 2 O 2 concentration was high during O3 treatment, OH radicals were likely to be scavenged by excess H2O2, leading to low PPCP degradation. Therefore, it is important to determine the appropriate H 2 O 2 dosage during O 3 treatment to improve PPCP degradation when adding H 2 O 2 during O 3 treatment.

Waternode station is a floating composite water quality monitoring device. The waternode station houses the multiple water quality measurement devices, control panel for wireless communication and solar cells for applying electric power. The floating devices are classified into general model with vertical dropping system and river model without vertical dropping system. The water quality measurement device measures pH, water temperature, conductivity, dissolved oxygen, turbidity and nitrate. And it measures all parameters simultaneously. The control panel is used for IP-USN system. USN (Ubiquitous Sensor Network) is a network system by water quality measurement devices. IP-USN is a USN system that identifies particular sensor connected to the internet. The data information is transferred by wireless modem based on TFB (Triple Frequency Band). Field application results showed that the waternode station is a reliable and cost-effective water quality monitoring solutions.

Metal elements or other constituents transported in urban and transportation land use rainfall runoff are often adsorbed on or incorporated with entrained particles that are ubiquitous in such runoff. EPP(Expanded Polypropylene) engineered media with a large surface area was developed to treat road runoff. Field application of particle filtration reactor(PFR), which combined the EPP engineered media with filtration called EcoTank system, provided control of water quality. Under the operating conditions with 0.55 hours hydraulic retention time(HRT) and a capable of treating a maximum road runoff 9.5 m3/h, the mean residual Cd, Cr, Cu, Pb and Zn were 0.24, 2.8, 13.4, 11 and 112.3 ㎍/L and corresponding percentage mean removal values were 91, 93, 85, 91 and 80%, respectively. Results suggest that a properly designed PFR can provide effective in situ control for particles and could be combined with or function separately from source control.

The water quality measurement device that we developed measures pH, water temperature, conductivity, dissolved oxygen, turbidity and nitrate. And it measures all parameters simultaneously. The water resistant and screw packing technology also applied for improved mechanical reliability during water quality monitoring. A comparison between the performances of major company products (YSI, Hydrolab etc.) and this device don't provide a stark contrast. This device was verified through the KOREA’s Environmental Examination Methods. This device is offered reliable and cost-effective water quality monitoring solutions. Upgrades will be available and will include the technologies that are self-cleaning optical sensors with integrated wipers remove biofouling and maintain high data accuracy and optimal power management and built-in battery compartment extends in situ monitoring periods.

Due to its irregular structure, the efficiency of the pelletized fibrous filter can be improved if the target substance is line-shaped. Thus, this study was conducted to examine the applications of the pelletized fibrous filter for biological sewage water with line-shaped particles. Towards this end, the pelletized fibrous filter was applied to advanced treatments in which the particles in the sewage water in the supernatant using solid-liquid separation from the final-settling reservoir was filtered with pelletized fibrous filters. To determine the process efficiency of the filter device, a multiparameter water quality analyzer and a data transmission system were established, which showed the efficient process even at a large distance, as well as the good operational status of the filter device. The pilot plant operation results showed that the concentration of TSS in the influent at 20-75 mg/L was reduced to 0.4-10 mg/L in the processed water. The average processing efficiency was 94.9% between 71.4 and 97.9%, and particularly, that of the suspended solids was very high. The results also showed that 27.2% CODMn, 22.5% T-N, and 30.0% T-P were removed.

In case of cleaning the tap water in Korea, focus has been concentrated on how to improve water quality during the process of purification after taking in original water. However, the interest in human health has been increased, so 'secondary contamination' ,polluted in the process of crossing water reservoir, distributing pipes, indoor water tanks and water pipes after water left a filtration plant, is soared up as an important object of water quality control. Especially the copper pipe for the tap water, its characteristic was acknowledged as a pipe with many merits such as excellent corrosion resistance and easy assembly at the time to lay, is being frequently used in the advanced countries like East Europe, North America, Australia, etc, and is also being used as the material of pipe laying among the pipes for distributing water in Germany and Netherlands. But in case of Korea, the blue or green water problem is found even in the less than 6 year old copper pipes after being installed newly in indoor pipe laying for water distributing that causes to bring about aesthetic distrust to citizens, so the necessity of study is raised to control this situation. In this study tried to control the corrosion and the blue and green water problem happening in the copper pipe using corrosion inhibitors to settle down the various problems available to happen by this problem and suggested an optimized method to manage this situation.

EPP(Expanded Polypropylene) media with a large surface area was developed to treat the first flush of storm water from motorway. A series of studies have been carried out concerning the main mechanism of physical characteristics with the filtration and adsorption of EPP media in EcoTank system in order to evaluate the performance risk for treating trace metals (Cd, Cr, Cu, Pb and Zn) under uncertainty. In view of quantitative and qualitative risk analysis, this study assesses the uncertainty analysis involved in predicting of treating heavy metals from road runoff using an EcoTank system. Results of treatment performance estimation after the treatment of trace metals using an uncertainty analysis were 50.0.% probability (class 3; moderate) for Cd, 52.0% probability (class 4; high) of Cr, 47.1% probability (class 3; moderate) for Cu, 44.4% probability (class 3; moderate) for Pb and 51.2% probability (class 4; high) for Zn, respectively. The performance risk values of all the heavy metals satisfied the acceptable criteria.

With the acceleration of urbanization, impervious surface spreads due to increase of rainfall effluent; consequently, plenty of pollutants occur instantaneously, and severity of a problem caused by being worse of the river and water system is coming to the forefront. Nation Water Quality Inventory reported that 30% of the cause of water quality getting worse is caused by non-point pollutants, and 64% of the cause of polluted water quality of the lake around North Carolina is resulted from non-point pollutants of urban area. This study developed a system that treats and removes pollutants occurring in an impervious area of the urban district by using polymer media. Polymer media, made from polypropylene materials, has float ability and an irregular form. Also this study showed that polymer media has an excellent filtering function of pollutants due to porosity on the surface, and the increase of specific surface area, so that it has an excellent function to remove suspended solids (SS), organic materials and nutritive salts in effluent water on the road side. Treatment efficiency of pollutants in an impervious area of the urban district through application of polymer media to the site is 92.1% and average EMC of suspended solids (SS) is 19.74 mg/L. In addition, treatment efficiency of CODcr is 82.3%, and the efficiency of TN and TP is 50.4% and 73.9%, respectively.

The cost for nonpoint source in urban area tends to increase as it's distanced farther from the pollution source. Thus it's more effective to dispose of the pollution at the pollution source. It becomes more difficult when nonpoint source is flowed into the surface water by stormwater. In case of combined sewer, increasing stormwater on impermeable surface causes the Combined Sewer Overflows (CSOs) containing the high level of pollutants which runs into the water system through the storm overflow diverging tank without treatment process. A huge amount of CSOs is generated instantly and as it carries the pollutants on impermeable surface as well as the deposits in sewage pipe, it's necessary to develop the technology for treatment of CSOs. This study was intended to develop the solid fabric filter which will be suitable for treatment of CSOs and the characteristic and performance of solid fabric filter were evaluated.

In this study, to effectively control urban non point source pollution, natural and artificial materials which were processed in various ways were charged as a filter media in a real size urban non point source pollution plant(EcoTank) and compared and evaluated the efficiency of filtering solid and organic compounds. The efficiency of filter media was evaluated after collecting dust from urban surface and artificially producing runoffs to evaluate runoff control efficiency of pollutants that caused from pollution in urban streets. To evaluate the efficiency of pollutants runoff control depending on different filter types, EPP(Expanded polypropylene), GAC(Granular activated carbon), Zeolite, Mix-1(EPP in the upper part, GAC in the lower part), Mix-2(GAC in the upper part, EPP in the lower part) was charged to the EcoTank and conducted experiments in an identical condition[6]. As a result of the filter evaluation using real size reactor, EPP was identified as the best filter media for non point source pollution runoff control, and the efficiency was in the following order: EPP > Mix-1 > Mix-2 > GAC > Zeolite.

This research was conducted to investigate the application of the novel upflow-type filtration device using hydrophobia media made of expanded polypropylene (EPP) from driveways site. The higher level of motorway-derived heavy metal contamination exists in stormwater runoff from a road section and the heavy metal levels were higher than the regulated Korean environmental guideline in lake and river. For Cd, Cr, Cu, Pb and Zn, the influent event mean concentrations (EMCs) during 8 storm periods were 2.75, 37.3, 90.5, 118.5 and 546.5 µg/L, respectively. The novel upflow-type filtration device with main mechanism of filtration and adsorption showed removal (>91%, >93%, >85%, >91% and >80%) of the studied heavy metals (Cd, Cr, Cu, Pb and Zn) and differences of medians of removal efficiencies among heavy metals were not statistically signficant by Kruskal-Wallis test (p>0.05) during 8 storm events. It is found that EPP media is very effective at the removal of the heavy metals, and the magnitude of heavy metal removal in a decreasing order is Cr, Cd, Pb, Cu and Zn.

Since the non point source is unspecified and estimating the degree of occurrence or identifying causing factors are difficult, it is not easy to control. Road runoff is considered a major source of pollution in developed urban sites. Road surfaces accumulate significant quantities of pollutants including nutrients, heavy metals and polycyclic aromatic hydrocarbons(PAHs). Many studies have characterized the constituents of stormwater. These constituents include polycyclic aromatic hydrocarbons(PAHs). Urban non-point source pollutant reducing treatment System is a part of the road runoff treatment which expanded polypropylene(EPP) media with a large surface area to treating the first flush of stormwater from road in field. Urban non-point source pollutant reducing treatment System consist of a container, a total 8.89m2 volume(3.6m(L), 1.3m(W), 1.9m(H)) which is made up of two element; sedimentation chamber of storage tank and filter tank. Under the operating conditions with 0.55h hydraulic retention time(HRT) and a capable of treating a maximum road runoff of 9.5m3/hr, the mean residual total PAHs were 0.699~1.339 µg /L and the percentage mean removal values were 61.4~69.7%, respectively.

本研究は嫌気性硫酸塩還元条件における高分子リグニンの分解について調べたものである。硫酸塩還元条件で，セルロースを共存基質として与え連続運転を行い，高分子リグニンの変化を定性的，定量的に追跡した。特に，高分子リグニンの分解に伴う分解産物として水溶性低分子リグニンであるAPPL (Acid Precipitable Polymeric Lignin) や芳香族化合物に着目した。その結果，高分子リグニンは硫酸塩還元条件下で最大12%の減少 (分解速度としては3.49mg/L/day) がみられ，低分子リグニンの構造を持つAPPLは増加する傾向を示した。この時hydrocinnamic acidなどの芳香族リグニンモノマーも同時に検出された。本研究の結果から高分子リグニンは硫酸塩還元条件下で，共存基質としてセルロースを利用して分解が促進されること，また，その分解が低分子化によって起こることが明らかになった。

This paper represents the statistical characteristics of sources and receptors for road traffic noise in apartment complex. Also we suggested that the site-specific characteristics of vertical and horizontal distributions in the complex apartment have been derived using a different analysis for evaluating levels of Leq1h by the apartment floor at a given distance from a road in terms of the flow rate, the mean speed of the traffic, and the percentage of the type vehicles in the day and night periods. As a result, the contribution orders of traffic quantity by the type of vehicles showed as followed: light vehicle>medium vehicle>heavy vehicle>motorcycle. Especially, the mixing ratio of entering the road on the heavy vehicle in the daytime was two times higher than that of in the night. The speed in all types of vehicle is in the range of 41 and 81 km/hr and noise level was not significantly different in day and night-time. The sources of road traffic noise had different variations and uncertainties using a random variable and probability distribution. The sound distribution to receptors by the apartment floor showed S curve between 1st floor and floor With the normality test, the normal distributions using Anderson-Darling Test followed and , floor in the daytime and all floors except floor in the night (p>0.05). And also, the value of the pearson correlation coefficient (r) obtained in this study have significantly different at the range of floor. In conclusion, the results suggested that the distribution characteristics of levels of on the sources and receptors of road traffic noise in apartment complex must be improved and developed on the guideline of regulation of road traffic noise.

Runoff from bridge impermeable surface is discharged directly into the receiving river or sewage pipe. However, generally, a bridge does not have sufficient space to place some treatment system. In this study, therefore, we investigated the down-flow filtration using expended polypropylene media (EPM) to treat runoff from bridge. Experiments were conducted employing down-flow filtration column (dh, 50600mm) to investigate the removal efficiency of pollutants. The EPM5, EPM10, EPM15 and f-EPM10 filters were developed from high molecular material, and were classified by different foaming rates and present of functional material. The experiment using f-EPM10 showed good hydraulic filtration performance without overflow for 1hr. But overflow, in the experiments using EPM5, EPM10 and EPM15, was observed within 1hr. Since f-EPM contains functional material, that can be improved water flow without clogging. The total SS removal efficiency of filtration equipment was rapidly decreased after overflow. In addition, a down-flow experiment, having slope of 15°, to avoid SS deposition at top of the column was carried out. Though SS deposition was found to be similar in two types flow, the flow of down-flow experiment, having slope of 15°, made progress without overflow for 3hr. This is because deposited SS didn’t intercept water inflow.

Lab-scale batch experiments using several 150-L transparent acrylic reactors were conducted to develop optimum capping materials that can capture phosphorous released from polluted lake sediments. The sediment used in the experiment was very fine clay (7.7 Φ in mean grain size), and organic carbon (Corg) content was as high as 2%. Four kinds of batches with different capping materials; powdered-gypsum (CaSO4·2H2O), granular-gypsum, sand, composite material (gypsum+sand), and one control batch were operated for 45 days. Phosphorous fluxes released from bottom sediments in the control batch were estimated to be 4.3 mg·m-2·d-1, while 0.9 mg·m-2·d-1, 1.0 mg·m-2·d-1, 2.2 mg·m-2·d-1, and 0.5 mg·m-2·d-1 in the batch capped with powdered-gypsum, granular-gypsum, sand, and composite material, respectively. The results obtained from lab-scale batch experiments show that there were 80% reduction of phosphorous for some materials such as powdered-gypsum, granular-gypsum, and composite material, whereas sand only about 50%. Increase in apatite-P fraction (48% → 80%) in the gypsum batches, compared to the control batch, indicates that abundant Ca2+ and SO4 2- ions from the gypsum added into oxygen-depleted sediment surface might have supplied abundant oxygen by reducing the sulfate ions very actively, resulting in Ca-P precipitates.

We developed the remodeling techniques of water storage tanks and the residual chlorine remaining devices. Eco-TIR((Total Internal Remodeling) is remodeling technique that cover the inside wall of concrete tank with SMC(Sheet Mold Compound) Block. Eco-SL(Stainless steel Lining) and Eco-GS(Glass sheet) is similar to Eco-TIR(Total Internal Remodeling) but stainless steel or glass tile is substituted for SMC block as a cover material. We tested the residual chlorine remaining devices and the results are as follows. First, it was estimated that mixing efficiency is increased if inflow energy to the water tank is used in the results of variation of residual chlorine concentration. Secondly, result showed that the removal percent of residual chlorine concentration was up to 90% by using ACF filter and feed water of high residual chlorine concentration can be controlled to 0.2mg/L〜0.4mg/L by using ACF and by-pass of inflow to the water tank. Also, in the water tank inlet pipe of 3-ways out using inflow energy is more effective in mixing than conventional inlet pipe. It is expected to enhance the safety of service water and management efficiency by applying mentioned techniques properly.

TiO2 nanocrystals (rod shape, ≤ 100 nm) were synthesized from TTIP/H2O2/H2O systems, and utilized as photocatalysts for degradation of humic acids (HAs) in the aqueous solution. The high purity TiO2 nanocrystals were obtained by excluding the use of inorganic acids that might consequently cause contamination of active catalytic surface sites of the nanocrystals by Cl, NO3 and SO4 . By varying H2O2/Ti=5.5~ 55, the crystalline phase of anatase/rutile ratio of the nanocrystals was controllable. The photocatalytic properties of the nanocrystals were strongly dependent upon the crystallinity and particle size. The DOC removal of humic acid was most effective for the nanocrystals prepared at H2O2/Ti=5.5 due to the mixed crystalline phase of anatase/rutile and the increased surface area by smaller particle size. The decreases of UV254 absorbance of HA solutions, which is caused by the conjugate double bond breakage, were much faster than those of DOC.

Electrooxidation is widely used to remove harmful organic and inorganic substances as well as pathogenic microorganisms. This study investigates the removal of Microcystis ichthyoblabe cells and their hepatotoxin microcystin-LR by the electrooxidation process using Pt/Ti electrodes. Additionally, the morphology changes and cell sizes were determined by scanning electron microscopy and a particle size analyzer, respectively. The algal cells were severely damaged by the electrooxidation process. During the initial treatment, intracellular microcystin-LR was released from the cells, increasing the extracellular microcystin-LR concentration. The electrooxidation charge required to remove cells and MC-LR was 3 × 10(4) C and 6 × 10(4) C, respectively. The removal efficiencies of M. ichthyoblabe cells and microcystin-LR were insensitive to initial cell density, initial microcystin-LR concentration and solution conductivity, but were heavily reduced at large algal suspension volume. Therefore, to achieve simultaneous removal of Microcystis cells and their MC, it is necessary to control the volume of algal suspension.

While more attention has been paid in recent years to urban point source pollution control, no considerable measures have been taken to control urban non-point source pollution. Contaminants from non-point sources deposited on urban impermeable surfaces such as road and highway are easily released to the public waters by rainfall, leading to the deterioration in water quality in urban area. Experiments were performed using a reactor and real rainwater runoff obtained from road surfaces at various pollutant loading and rainfall intensity to determine the criteria for the first flush rainwater and to evaluate the applicability of the reactor for treating road runoff. The results at different rainfall intensities show that the medium PPB is superior to the other media for water permeability. PPB was not blocked at 10 mm/hr rainfall, and its permeability was stable. On the other hand, PVS and PPF resulted in a substantial overflow ratio even at 1 mm/hr rainfall intensity. Comparison of treatment efficiencies for suspended solids showed that all media showed similar removal efficiency ranging from 91% to 95%. However, PPB seems to be better than the other media considering its higher water permeability. PPB and PPF, both hydrophobic, yielded over 76% of heavy metal removal. But the hydrophilic media PVS showed much smaller removal efficiency ranging from 26% to 47%. The treatment efficiencies over PAHs (Poly Aromatic Hydrocarbons) showed the similar removal efficiency ranging from 66% to 97% for all three media. In this study a reactor using filter media was investigated to reduce the level of contamination in urban road runoff.

Urban runoff is one of the major sources that contaminates water supplies because it contains toxic compounds such as heavy metals and PAHs (poly aromatic hydrocarbons) as well as suspended solids, organic compounds, and nutrients. The eingineered polymetric media in this research were developed as filtering media in the storm water treatment equipment. The media used in this study can remove contaminants in urban runoff via adsorption and filtration. The engineered media composed of polypropylene and anion surfactant were foamed to have buoyacy and then shattered by mechanical device for efficient filtration. Surface characteristics of the engineered media were determined by using a scanning electron microscope and a microscope. Results indicated that surface area of the engineered media were increased from less than 0.05m2/g for the neither foamed nor shattered media to 7.82m2/g for the foamed and shattered media. Specific gravity of the media that were foamed and shattered was 0.108~0.154 whereas the non-treated media had specific gravity of 0.914. Fractal dimension of media was measured for the irregularity of the media shape and the media that had high fractal dimension value was performed high filtration efficiency of suspended solids in runoff.