본 사례는 최근 준공된 “구미하수처리장 하수처리수를 이용한 재이용시설”에 대한 것으로 이 시설은 구미하수처리장의 2차 처리수를 원수로, 응집침전시설, 전처리시설, 주처리시설과 재이용수 공급시설로 구성되어 있으며, 설비의 성능 확인을 위한 시운전을 완료하였다. 주처리시설로는 역삼투막(RO Membrane)을 적용하였으며, 하수처리수 내 잔류물질로 인한 역삼투막 성능저하방지와 수요처의 요구수질 충족을 위해 활성탄 주입을 포함한 응집침전공정과 정밀여과막(Micro Filter)을 전처리시설로 구성하였다. 사업 초기단계에 현재 시공된 것과 동일한 공정으로 구성된 Pilot Plant를 건설, 운영하여, 반영된 각 단계별 공정의 적정성과 주요 설계 인자를 확인하였으며, 일부 확인된 개선 사항은 실시설계시 반영하였다.

The ecosystem in the Gwangju Stream has taken a wide range of disturbance such as the discharging water of sewage treatment plant, the lake water and the river water from different water system over the past decade. This study was figured out some significant influence factors by analyzing the relationship between biotic and abiotic factors in the urban stream. Abiotic components included 15 water quality variables which were measured in five sampling sites along the stream from October 2014 to July 2015, whereas the benthic macroinvertebrates found in those sites were used to estimate various biotic indices representing the ecological status of the community. The results of correlation analyses indicated that abiotic factors by human activities affected on the inhabitation of benthic macroinvertebrates more than biotic factors. The results of cluster analyses and ANOVA tests also showed that biotic and abiotic characteristics were clearly different in season. The main influence factors of cluster analysis by sites were NH3-N, EPT(I) and DO. It was considered that more various statistical analyses would be necessary to find some different relationships and influence factors between biotic and abiotic variables in the urban stream.

The sewage and wastewater (SAW) are a well-known major source of eutrophication and greentide in freshwaters and also a potential source of thermal pollution; however, there were few approaches to thermal effluent of SAW in Korea. This study was performed to understand the behavioral dynamics of the thermal effluents and their effects on the water quality of the connected streams during winter season, considering domestic sewage, industrial wastewater and hot spring wastewater from December 2015 to February 2016. Sampling stations were selected the upstream, the outlet of SAW, and the downstream in each connected stream, and the water temperature change was monitored toward the downstream from the discharging point of SAW. The temperature effect and its range of SAW on the stream were dependent not only on the effluent temperature and quantity but also on the local air temperature, water temperature and stream discharge. The SAW effects on the stream water temperature were observed with temperature increase by 2.1~5.8℃ in the range of 1.0 to 5.5 km downstream. Temperature effect was the greatest in the hot spring wastewater despite of small amount of effluent. The SAW was not only related to temperature but also to the increase of organic matter and nutrients in the connected stream. The industrial wastewater effluent was discharged with high concentration of nitrogen, while the hot spring wastewater was high in both phosphorus and nitrogen. The difference between these cases was due to with and without chemical T-P treatment in the industrial and the hot spring wastewater, respectively. The chlorophyll-a content of the attached algae was high at the outlet of SAW and the downstream reach, mostly in eutrophic level. These ecological results were presumably due to the high water temperature and phosphorus concentration in the stream brought by the thermal effluents of SAW. These results suggest that high temperature of the SAW needs to be emphasized when evaluating its effects on the stream water quality (water temperature, fertility) through a systematized spatial and temporal investigation.

Control degree and property changes of dissolved organic matter (DOM) were conducted by coagulation of chemical treatment for 2 sewage treatment plants with different technical methods. As the result, SUVA value of the second treated water (supernatant of the second settling pond after biological treatment) was increased and DOC was reduced in comparison with supplied raw water. And, SUVA value and DOC were reduced by coagulation after coagulation treatment of the second treated water. Properties of dissolved organic matter for 2 sewage treatment plants's DOC were divided. As the result, there was lots of hydrophilic component with hydrophilicity in case of plant A. In case of the second treated water, Plant A showed fulvic acid with little molecular weight was reduced among the hydrophobic component with hydrophobicity, but numic acide with lots of molecular weight was increased. However, in case of plant B, both fulvic acid with little molecular weight and humic acid with lots of molecular weight were increased among the hydrophobic components with hydrophilicity. Before the operation of phosphorus facility, properties of dissolved organic matter after biodegradation with effluent water showed hydrophilic components were reduced and hydrophobic components were increased. However, after coagulation treatment of the second treated water, hydrophilic components and hydrophobic components were outstandingly decreased or increased. During the biodegradation after coagulation treatment, hydrophilic components were significantly decreased and hydrophobic components were increased.

비료를 유도용액으로 사용하는 정삼투를 하수처리수(2차 침전지 유출수)의 재이용에 적용하여 유도용액의 성능을 평가하였다. 일반적으로 많이 사용되고 있는 비료 중에서 삼투압, 용해도 및 pH 등을 고려하여 NH4H2PO4, KCl, KNO3, NH4Cl, (NH4)2HPO4, NH4NO3, NH4HCO3 및 KHCO3을 유도용액 후보군으로 선정하고, 수투과선속 및 역용질선속을 측정하 여 유도용액의 성능을 평가하였다. 평균 수투과선속은 KCl > NH4Cl > NH4NO3 > KNO3 > KHCO3 > NH4HCO3 > NH4H2PO4 > (NH4)2HPO4의 순서로 나타났으며, KCl을 유도용액으로 사용하였을 때, 평균 수투과선속은 13.49 LMH이었다. 하수처리장 2차 침전지 유출수의 삼투압은 탈이온수의 삼투압에 비해 큰 차이가 없었다. 역용질선속은 NH4H2PO4 < NH4Cl < (NH4)2HPO4 < KNO3 < NH4HCO3 < NH4NO3의 순서로 나타났으며, NH4H2PO4를 유도용액으로 사용하였을 때, 역용질선 속은 4.96 × 10-3 mmol/m2⋅sec이었다.

본 연구에서는 하수처리수를 원수로 사용하여 직접 접촉식 막증발법을 적용하여 원수 온도와 원수 유량 변화에 따 른 하수처리수의 COD, TN, TP, TOC의 제거율 변화와 여과플럭스의 변화를 측정하였다. 또한 하수처리수에 의한 분리막의 오염 가역성을 평가하기 위해 1차 증류수만을 사용하여 물리세정을 수행한 후 플럭스의 회복률을 측정하였다. 실험결과 원수 의 온도 및 유량에 관계없이 원수가 3배 농축될 때까지 여과를 진행하였음에도 불구하고 하수처리수의 주요 오염물질인 COD, TN, TP, TOC에 대한 제거율이 92% 이상으로 높게 나타났다. 또한 비교적 낮은 온도인 50°C와 60°C에서 원수의 유량에 따라 최소 13.8 LMH에서 20.3 LMH로 높은 여과플럭스를 나타냈다. 그리고 높은 농축계수까지 여과 실험을 진행했음에도 불구하 고 낮은 여과플럭스의 감소를 나타냈으며 1차 증류수를 이용한 짧은 시간 동안의 물리세정만으로 최소 90% 이상의 높은 여과 플럭스 회복율을 나타냈다. 따라서 하수처리수 재이용을 위한 공정으로 막증발법의 적용이 충분히 가능할 것으로 판단된다.

본 연구는 하수를 공업용수로 재이용하기 위한 분리막 시스템 적용에 관한 연구이다. 정밀여과와 역삼투시스템으로 구성된 bench scale 실험장치를 이용하여 하수처리장 현장에서 실험을 수행한 결과, 정밀여과 시스템은 이온성분은 제거할 수 없었으나 SS를 70% 이상 처리할 수 있어 처리수는 직접냉각수로 재이용이 가능하였다. 그리고 역삼투 시스템은 SS는 물론 이온성분도 95% 이상 제거할 수 있어 처리수는 간접냉각수 및 제품세척수로 사용이 가능하였다. 100 m3/일 용량의 pilot Plant를 제작하기 위해서는 정밀여과 모듈은 20개, 역삼투 모듈은 12개가 필요하였다.

본 연구는 온배수가 인근 소하천의 수질과 농경지내 오염성분함량 변동에 미치는 영향을 구명하고 이에 대한 대책을 수립하는데 활용하고자 1997년 1월부터 1998년 9월 사이에 수행되었다. 온배수 유입으로 인근 소하천 물 중의 PO43-, SO42-, Cl-, NH4 -N, Ca2+, Na+ 및 COD성분함량은 농업용수 기준보다 낮았으며 유거 거리가 길어질수록 이들 농도는 더욱 낮아졌다. 유출된 온배수 중 SO42

This study was carried out to investigate the economic and environmentally friendly process of drying sludge by combining a mechanical dewatering filter press and thermal dryer. The dryer for 40 kg/hr of dewatered sludge consisted of a main dryer, a heat exchanger, a pre-dryer, and supplementary equipment. During the dewatering process, 100 kg of sludge with 80.11% water content was diluted and mixed with 400 kg of water and ferric chloride solution was added as a sludge conditioner. The average water content of dewatered sludge cake was 60.9% and the energy consumption rate (ECR) for removing water was 226.9 kcal/kg-H2O. Hot flue gas generated from the main dryer was utilized as heating air for the pre-dryer in the heat exchanger. When 36 kg/hr of dewatered sludge cake was dried, the ECR was 1,009 kcal/kg-H2O with 3.96% water content. The combined operation of the dewatering and the thermal drying processes showed that the ECR was reduced sharply to 521 kcal/kg-H2O. The high humidity gas generated from each drying unit in the main dryer was recirculated to the odor decomposition chamber in the main dryer to destroy odor components at a high temperature. The odor concentration of humid gas generated by the pre-dryer was very low due to the relatively low operating temperature.

The efficiencies of Gang-Byeon sewage treatment facilities, which are based on GPS-X modelling, were analysed and used to design recycle water treatment processes. The effluent of an aeration tank contained total kjeldahl nitrogen (TKN) of 1.8 mg/L with both C-1 and C-2 conditions, confirming that most ammonia nitrogen (NH3 +-N) was converted to nitrate nitrogen (NO3 --N). The concentrations of NH3 +-N and NO3 --N were found to be 222.5 and 227.2 mg/L, respectively, with C-1 conditions and 212.2 and 80.4 mg/L with C-2 conditions. Although C-2 conditions with higher organic matter yielded a slightly higher nitrogen removal efficiency, sufficient denitrification was not observed to meet the discharge standards. For the total nitrogen (T-N) removal efficiency, the final effluent concentrations of T-N were 293.8 mg/L with biochemical oxygen demand (BOD) of 2,500 mg/L, being about 1.5 times lower than that (445.3 mg/L) with BOD of 2,000 mg/L. Therefore, an external carbon source to increase the C/N ratio was required to get sufficient denitrification. During the winter period with temperature less than 10 , the denitrification efficiency was dropped rapidly even with a high TKN concentration (1,500 mg/L). This indicates that unit reactors (anoxic/aerobic tanks) for winter need to be installed to increase the hydraulic retention time. Thus, to enhance nitrification and denitrification efficiencies, flexible operations with seasons are recommended for nitrification/anoxic/denitrification tanks.

The treatment efficiencies of domestic sewage treatment processes were analysed and assessed to suggest and design a suitable technology for coal seam gas (CSG) water treatment. Two sewage treatment plants (S and G in Busan) were selected. The former operates with standard activated sludge and modified Ludzak Ettinger processes while the later uses the combination of A2/O and gravity fiber filtration. For both plants, the concentrations of BOD, CODMn, T-N and T-P were about 5.0, 19.0, 5.0, 11.0 and 1.0 ppm, respectively, which satisfy the discharge standards. Therefore, although sewage treatment processes seems to be applicable for CSG water treatment, additional processes to remove total dissolved solids and ionic compounds (i.e. bicarbonate) need to be introduced to produce fit-for-purpose water resources for beneficial use (in accordance with Water ACT 2013). This, for the CSG treatment process design, it is necessary to align the operating conditions with merging methods of combinable unit technology obtained from sewage treatment processes.

Since the ground subsidence frequently occurs caused by water and sewage pipeline leakage, this paper reviews current maintenance management regulation, legislation related to water and sewage pipeline measurement for maintenance in practice to prevent and manage this phenomenon. Analysis of current system shows the difficulty of ground subsidence evaluation and importance of the law which is now being established has been emerged. In addition, it is determined that the regulation contains specified content with specific range of water and sewage pipeline is required for its maintenance.

Because aging sewer on the ground due to cavitation are a lot of social problems occur, the existing aging pipes are to be replaced. But is not easy to accurately detect the aging water and sewage pipes. In this research, we present a technique that can detect defective sewerage pipes used in GPR through Test-bed, which can be used as urban planning resources for water supply and drainage pipes replaced.

This study was carried out to analyze the disparities of basic living infrastructure between Guns(rural counties), and between Eups/Myuns(rural districts) in Jeollanam-do province. For the purpose of this study, dimensions of regional disparity in basic living structure were measured by 3 components ; road, public water service and sewage disposal. By utilizing the published statistics, this study has examined 8 Guns(counties) containing Eup and Myon in Jeollanam-do province which can represent 4 different rural areal types, respectively, i,e. mountainous, semi-mountainous, flat and seashore areas. The data acquisition time of this study is fixed on end of 2009 year in order for possible collections of the most recent published statistics. It presents evidence on the magnitude and evolution of discussion of regional disparities between Guns(counties), and between Eup & Myon, and between Myons in Jeollanam-do province even though infrastructure provision level of Jeollanam-do rural areas are much more improved than the past. Concludingly, the existing disparities in this area is meaningful and so, it should be seriously reconsidered when deciding local government's budget allocation priority.

There is an increasing incidence in health problems related to environmental issues that originate from inadequate treatment of sewage. This has compelled scientists to engage in innovative technologies to achieve a effective disinfection process. Electrolysis has emerged as one of the more feasible alternatives to conventional disinfection process. The objectives of the present paper were to investigate the effect of chemical characteristics on oxidant formation and Escherichia coli (E. coli) disinfection in synthetic sewage effluents. The influence of parameters such as COD, SS, T-N and T-P were investigated using laboratory scale batch reactor. The results showed that the higher COD, T-N and T-P concentration, the lower N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) degradation and E. coli disinfection was observed. The order of effect of RNO degradation and E. coli disinfection was T-P > COD > T-N > SS. When 4 parameter of water quality were worked simultaneously, oxidants formation and disinfection was decreased with increase of the concentration of sewage. To increase of the disinfection performance, the increase of disinfection time or electric power was need.

To acquire preliminary data for the control of total nitrogen (TN) in S sewage treatment plant, which processes merging food waste and sewage, the effect of reject water on the total nitrogen in the effluent was examined in this study. Water quality data for the plant during the winter period were applied to calculate the mass balance. It was calculated that at least more than 231 kg/d TN should be removed to control the TN concentration in the effluent. Assuming 18 ppm as the goal TN concentration in the effluent, about 941 kg/d TN should be removed from this plant. Approximately 10% more TN should be removed than at present to achieve this result. It was observed that dewatering the filtrate had a considerably greater effect on the total nitrogen in the effluent than the reject waters. The dewatered filtrate contained 1,399kg/d TN. The contribution of the dewatered filtrate to the TN concentration in the effluent was 0.183, which was 7 to 23 times greater than the other reject waters. In addition, the amount of total nitrogen from the reject water, with the exception of the dewatering filtrate, was lower than the amount of TN that should be removed from S sewage treatment plant. Therefore, it was concluded that one of the most effective methods for controlling the TN concentration in effluent was the removal of the TN contained in the dewatering filtrate.

6～13 ㎎/L base water concentration on monthly BOD has been kept at the Geukrak bridge point for this research target and it indicates the water quality under the existed rank. Due to this present condition of water quality, the demage of ecology from the upper stream to the lower one of the bridge could be conjectured. Moreover, nonstructural extinction of the ecology seems to have gotten worse between both the streams of Yeoungsan River. On this research, eco-corridor between the upper stream and the lower stream of the river should be ensured, the ecological demage needs to be cut off, a dispersed discharge method which the existed method of the 1st sewage plant in Gwangju was enhanced to should be inducted for the procuring of various water ecosystem, and the conditions by the scenario suggested from this research could be applied to a water quality model. then, analysis the improvement effect of the water quality adjacent the river. From the test result, Case3-Type1 scenario is thought to be the best one. From the test result with Case3-Type1, when the concentrated discharge was never done, 0.07 mg/L of BOD concentration was increased at the lower stream where Yeoungbon B point (Haksan Bridge) is but the water improvement effect of 0.24～2.87 mg/L is thought to have been done at the area of water deterioration.

For the sustainable management of marine ecosystem in Masan Bay, we have to assess the carrying capacity and standard of target water quality. In this research, we assume that all pollutants loads are treated in Dukdong sewage treatment plant, then we simulate the physical-biological model for prediction water quality for the achievement of standard water quality. In 2001 year, for the achievement of COD 2.5 mg/L, we need to reduce COD 90 %, nitrogen 30 %, phosphate 90% than that of the present value. According to these results, the water quality of sewage treatment plant is required to treat COD 13.5 mg/L, nitrogen 33.3 mg/L, phosphate 6.0 mg/L. If the sewage treatment plant will be expanded much larger in 2011, it will need to be treated in COD 6.6 mg/L, nitrogen 2.5 mg/L, phosphate 5 mg/L for the achievement of water quality standard in COD 2.5 mg/L.

This study was performed to improve water demand estimation and analize correlation between generation of domestic sewage and domestic water use. To improve the prediction of water demand estimation, new water demand equation was developed. The results is as follows. InQt = β0 + β₁InPt + β₂InYt + β₃InHt + εt By using the statistical analysis of the "generation of domestic sewage" and "domestic water use", the regression equation between them is formed. The result is as follows. ＿ Generation of domestic sewage = 0.8487 × Domestic water use + 684.57 (R² = 0.972)