하돈우 Don-woo Ha , 심홍빈 Hongbin Shim , 김해성 Haesung Kim , 김윤수 Yoonsoo Kim , 조소현 Sohyun Cho , 송창수 Chang-soo Song , 강태구 Taegu Kang , 김영석 Yeong-suk Kim

DOI:10.15681/KSWE.2017.34.1.1 Vol.34(No.1) 1-9, 2018

In this study, the load of the river was calculated by using the actual data of the Yeong-bon C1, Yeong-bon C2, Yeong-bon C3 monitoring points of the Yeong-san river watershed to determine the excess. As a result, the BOD is 75.83 % at the Yeong-bon C1 and the five-year average value is higher than at other points. The Yeong-bon C3 was 72.15 % and Yeong-bon C2 was analyzed as 68.78 %. The five-year average of the T-P was 71.95 % for the Yeong-bon C2 and 69.86 % for the Yeong-bon C3 and 69.16 % for Yeong-bon C1; these levels exceeded the target water quality standards of 50 %. As a result of analyzing the pollutant load, we found that the Yeong-bon C1 has been highly affected by the nonpoint pollution source because the excess rate is high in the upper section of the flow rate. The Yeong-bon C2 showed a high excess rate in the lower part of the flow rate, and it was estimated that the influence of the point pollution source was large. The excess rate of the Yeong-bon C3 is small in the interval deviation, and it was evaluated as being affected by both point and non-point pollution sources. The TMDL monitoring network data were used to estimate the exceed ratio for the target water quality assessment, and the implementation evaluation was made by the flow exceedance probability interval to analyze the monitoring data so that the data could be utilized according to the purpose of the measurement network.

Discharge load characteristics, TMDLs, Tributary monitoring, Yeongsan river basin

김예지 Ye Ji Kim , 공동수 Dongsoo Kong

DOI:10.15681/KSWE.2017.34.1.10 Vol.34(No.1) 10-25, 2018

This study was conducted to estimate the habitat suitability of 17 benthic macroinvertebrate taxa in the Hwayang stream. Habitat Suitability Index (HSI) of benthic macroinvertebrates from the Hwayang stream was developed based on three physical habitat factors which include current velocity, water depth, and the substrate. The Weibull model was used as a probability density function to analyze the distribution of individual abundance by physical factors. The number of species and the total individual abundance increased along with the increase in current velocity. By means of Canonical Correspondence Analysis (CCA), the relative importance of each factor was determined in the following order: current velocity, water depth, and the mean diameter. The results depicted that, the most influential factor in the growth of benthic macroinvertebrates in the Hwavang system was current velocity. After comparing the analyzed results from the Hwayang stream with the resukts from the Gapyeong stream, the integrated HSI was drawn. The results indicated that current velocity and substrate had similar distributions of HSI in the two streams. This was due to the addition of unmeasured data from previous surveys, or the fact that benthic macroinvertebrates adapted to deeper waters in the Hwayang Stream. Most taxa showed a clear preference for a fast current velocity, deep water depth and coarse substrate except Baetiella, Epeorus, (mayflies), and Hydropsyche (caddisfly).

Benthic macroinvertebrates, Environmental flow, Habitat Suitability Index, Hwayang stream

오경희 Kyoung-hee Oh , 김성진 Sung-jin Kim , 조영철 Young-cheol Cho

DOI:10.15681/KSWE.2017.34.1.26 Vol.34(No.1) 26-32, 2018

In order to analyze the effects of sediment on the occurrence of algal bloom on the Giheung Reservoir, the contamination levels of sediments were evaluated. The concentrations of various organic compounds (ignition loss), as well as the total nitrogen, total phosphorus, and heavy metals (Zn, Cr, Co, Ni, Pb, As, Hg, Cd) were analyzed in the sediments taken at eighteen sites of the reservoir. The concentrations of ignition loss and total nitrogen tended to increase from upstream to downstream, and ranged from 4.38 to 12.93% and 2,153 to 4,723 mg/kg, respectively. Heavy metals were in the order of Zn>Cr>Co>Ni>Pb>As>Hg, and the contamination level of the heavy metals was not high as a whole. The concentrations of the total phosphorus were in the range of 765 ~ 3,238 mg/kg, which exceeded the contamination level of the「Sediment Quality Assessment Guideline of River and Lake Sediment (Rule No. 2015-687 of the National Institute of Environmental Research, Korea)」at two upstream sites, four downstream sites, and all downstream sites. These results indicated that the pollution level of the total phosphorus, which is the main factor related to algal bloom, was found to be serious. Therefore, it is necessary to establish a countermeasure for sediment management in order to control the algal bloom which occurs periodically in the reservoir.

Contamination level, Giheung Reservoir, Ignition loss, Sediment, Total nitrogen, Total phosphorus

이은정 Eun Jeong Lee , 김태근 Tae Geun Kim , 금호준 Ho Jun Keum

DOI:10.15681/KSWE.2017.34.1.33 Vol.34(No.1) 33-45, 2018

In this study, we discussed the application of Watershed model and Load Duration Curves (LDC) in Total Water Load Management System. The Flow Duration Curves (FDC) and the LDC were generated using the results of the daily HSPF model and analyzed on monthly or yearly flow duration variability, and non-point pollutant discharge loads by entire flow conditions. As a result of the calibration and verification of the HSPF model, both the flow and the water quality were appropriately simulated. The simulated values were used to generate the Flow Duration Curve and the Load Duration Curve, and then the excess rate by entire flow conditions was analyzed. The point and non-point pollutant discharge loads for entire flow conditions were calculated. It is possible to evaluate the variability of water quality in specific flow duration through the curves reflecting the flow duration variability and to confirm the characteristics of the pollutant source. For a more scientific Total Water Load Management System, it is necessary to switch from a current system to a system that can take into account the entire flow conditions. For this, the application of the watershed model and load duration curve is considered to be the best alternative.

FDC, HSPF model, LDC, Total Water Load Management System

정현철 Hyunchul Jung , 임병철 Byoungcheol Yim , 임수진 Sujin Lim , 김병희 Byounghee Kim , 윤병수 Byoungsu Yoon , 이옥민 Okmin Lee

DOI:10.15681/KSWE.2017.34.1.46 Vol.34(No.1) 46-56, 2018

A mcyB-specific Ultra-Rapid quantitative PCR was developed for the quantitative detection of Microcystis aeruginosa, which is often a dominant species in green tide. McyB-specific UR-qPCR was optimized under extremely short times of each step in thermal cycles, based on the specific primers deduced from the mcyB in microcystin synthetase of M. aeruginosa. The M. aeruginosa strain KG07 was used as a standard for quantification, after the microscopic counting and calculation by mcyB-specific UR-qPCR. The water samples from the river water with the Microcystis outbreak were also measured by using both methods. The 1.0 × 10⁸ molecules of mcyB-specific DNA was recognized inner 4 minutes after beginning of UR-qPCR, while 1.0 × 10⁴ molecules of mcyB-specific templates was detected inner 7 minutes with quantitative manner. From the range of 1.0 × 10² to 1.0 × 10⁸ initial molecules, quantification was well established based on C_T using mcyB-specific UR-qPCR (Regression coefficiency, R² = 0.9977). Between the numbers of M. aeruginosa cell counting under microscope and calculated numbers using mcyB-specific UR-qPCR, some differences were often found. The reasons for these differences were discussed; therefore, easy compensation method was proposed that was dependent on the numbers of the cell counting. Additionally, to easily extract the genomic DNA (gDNA) from the samples, a freeze-fracturing of water-sample using liquid nitrogen was tested, by excluding the conventional gDNA extraction method. It was also verified that there were no significant differences using the UR-qPCR with both gDNAs. In conclusion, the mcyB-specific UR-qPCR that we proposed would be expected to be a useful tool for rapid quantification and easy monitoring of M. aeruginosa in environmental water.

Cyanobacteria, Microcystin, Microcystis, Quantitative PCR, Ultra-Rapid PCR

백종석 Jongseok Baek , 이상진 Sangjin Lee , 신현석 Hyunsuk Shin , 김형산 Hyungsan Kim

DOI:10.15681/KSWE.2017.34.1.57 Vol.34(No.1) 57-66, 2018

Water disasters such as flash floods and inundation caused by localized heavy rainfall in urban areas have a large impact on climate change but are also closely related to the increase in impervious areas as pointed out in domestic and international studies. It is difficult to secure natural green areas in urban areas that have already been developed. So, urban regeneration can be expected using water management optimized with technologies to secure infiltration and storage capacity such as Low-Impact Development technology. In this study, the water cycle improvement ability was confirmed by applying the LID technology within the district unit plan of the environmentally friendly village, and the economic feasibility of LID application was analyzed by estimating the costs and benefits of installing the facilities. The site was planned to conserve sufficient green and plans for securing the watershed infiltration and storage capacity were formulated with the application of additional LID technology, such as infiltration trenches, rain barrels and permeable pavements. The LID design method applicable to the site was established, and the water balance of the watershed was analyzed through simulations of the SWMM model. The water circulation improvement effect was confirmed through the water balance analysis, and the cost-benefits were determined according to the estimation method, and the economic analysis was conducted. This study confirms that the investment of LID technology is economically feasible for the hydrological improvement effect of the housing complex.

Cost-benefit, EPA SWMM, LID, Water balance, Water cycle

소재민 So Jae-min , 김정배 Kim Jeong-bae , 배덕효 Bae Deg-hyo

DOI:10.15681/KSWE.2017.34.1.67 Vol.34(No.1) 67-76, 2018

There are 34 mega-cities with a population of more than 10 million in the world. One of the highly populated cities in the world is Seoul in South Korea. Seoul receives 1,140 million m3/year for domestic water, 2 million m3/year for agricultural water and 6 million m3/year for industrial water from multi-purpose dams. The maintenance water used for water conservation, ecosystem protection and landscape preservation is 158 million m3/year, which is supplied from natural precipitation. Recently, the use of the other water for preservation of water quality and ecosystem protection in urban areas is increasing. The objectives of this study is to develop the seasonal forecast method of environmental water in urban areas (Seoul, Daejeon, Gwangju, Busan) and to evaluate its predictability. In order to estimate the seasonal outlook information of environmental water from Land Surface Model (LSM), we used the observation weather data of Automated Synoptic Observing System (ASOS) sites, forecast and hind cast data of GloSea5. In the past 30 years (1985 ~ 2014), precipitation, natural runoff and Urban Environmental Water Index (UEI) were analyzed in the 4 urban areas. We calculated the seasonal outlook values of the UEI based on GloSea5 for 2015 year and compared it to UEI based on observed data. The seasonal outlook of UEI in urban areas presented high predictability in the spring, autumn and winter. Studies have depicted that the proposed UEI will be useful for evaluating urban environmental water and the predictability of UEI using GloSea5 forecast data is likely to be high in the order of autumn, winter, spring and summer.

GloSea5, Land Surface Model, Seasonal Outlook, Urban Environmental Water, Urban Environmental water Index

신기식 Kisik Shin , 김종민 Jongmin Kim , 이수형 Soohyung Lee , 이정서 Jungseo Lee , 이택준 Taekjune Lee

DOI:10.15681/KSWE.2017.34.1.77 Vol.34(No.1) 77-83, 2018

This paper aims to evaluate the results of toxicity testing with Daphnia magna and Vibrio fischeri on wastewater samples which might be influenced by ion imbalance. The effluents from factories were found to be more toxic with high salinity levels than those from public wastewater treatment plant (WTP) and sewage treatment plant (SWP). Clion composition was highest in the effluent, in terms of percentage, which was followed by Na⁺, SO₄ ^2- and Ca²⁺. K⁺ and Mg²⁺ ion was relatively low. The sensitivity of D. magna test results was higher than V. fischeri. Among samples which were proved by V. fischeri testing to be nontoxic, the composition ratio of each ion whether toxic samples or nontoxic samples which were decided by D. magna toxicity testing, were compared. Na⁺, K⁺, Ca²⁺, Mg²⁺ ion composition ratio showed high level in nontoxic samples whereas SO₄ ^2- and Cl- ion composition ratio was high in toxic samples. Accordingly, SO₄ ^2- and Cl- ion seemed to be considered the ions causing toxicity in effluent. Toxicity from some categories of industries (Mining of non-metallic minerals, Manufacture of basic organic petrochemicals, Manufacture of other basic organic chemicals, Manufacture of other chemical products etc.) seemed to be influenced by salinity. The Ion concentration in influent and effluent were similar. Concentration of Na⁺, Cl^-, K⁺, Ca²⁺ ions were high in influent, however Mg²⁺ and SO₄ ^2- ions were high in effluent.

Daphnia magna, Effluent, Ion imbalance, Salinity, Vibrio fischeri

김필재 Piljae Kim , 김아름 Ah Reum Kim , 권용주 Yongju Kwon , 민정기 Jeong Ki Min , 허인애 In Ae Huh , 공동수 Dongsoo Kong

DOI:10.15681/KSWE.2017.34.1.84 Vol.34(No.1) 84-95, 2018

The community structure of benthic macroinvertebrates in the fine sediments of freshwater was analyzed according to various sampling tools and methods. The sediment core with the inner diameter of 7.5 cm was more effective in cost and labor in comparison to that of Φ 5 cm or Φ 10 cm. The number of species increased with the increase in sample size (replicates). When it was collected five times with the Φ 7.5 cm sediment core, Shannon-Weaver's diversity and McNaughton’s dominance of the sample reached about the 80 % level of the community estimates. Most species appeared in the sediment layer of 0-4 cm, and there were no newly recruited species below the depth of 4 cm. Individual abundance of benthic macroinvertebrates decreased exponentially along with the increase in sediment depth. Compared with the individual abundance of the 0-15 cm sediment layer, the abundance was 60 % in the 0-2 cm layer, 25 % in the 2-4 cm layer, 10 % in the 4-6 cm layer and 95 % in the 0-6 cm layer. Compared with organisms collected with the sieve of 0.2 mm pore, the number of species and the individual abundance sifted through the sieve with pore of 1 mm were 36 % and 88 %, and those with pore of 0.5 mm were 5 % and 55 %, respectively.

Benthic macroinvertebrate, Community structure, Sampling methods, Sediment

박홍근 Hongkeun Park , 유대환 Daehwan Rhu

DOI:10.15681/KSWE.2017.34.1.96 Vol.34(No.1) 96-108, 2018

Large efforts have recently been made on research and development of sustainable and energy-efficient short-cut nitrogen removal processes owing to strong attention to the energy neutral/positive wastewater treatment system. Anaerobic ammonium oxidizing bacteria (anammox bacteria) have been highlighted since 1990’s due to their unique advantages including 60% less energy consumption, nearly 100% reduction for carbon source requirement, and 80% less sludge production. Side-stream short-cut nitrogen removal using anammox bacteria and partial nitritation anammox (PN/A) has been well established, whereas substantial challenges remain to be addressed mainly due to undesired main-stream conditions for anammox bacteria. These include low temperature, low concentrations of ammonia, nitrite, free ammonia, free nitrous acid or a combination of those. In addition, an anammox side-stream nitrogen management is insufficient to reduce overall energy consumption for energy-neutral or energy positive water resource recovery facility (WRRF) and at the same time to comply with nitrogen discharge regulation. This implies the development of the successful main-stream anammox based technology will accelerate a conversion of current wastewater treatment plants to sustainable water and energy recovery facility. This study discusses the status of the research, key mechanisms & interactions of the protagonists in the main-stream PN/A, and control parameters and major challenges in process development.

Main-stream Partial Nitritation - Anammox (PN/A), Short-cut Nitrogen Removal

박영현 Younghyun Park , 김정미 Jeongmi Kim , 최원영 Wonyoung Choi , 유재철 Jaecheul Yu , 이태호 Taeho Lee

DOI:10.15681/KSWE.2017.34.1.109 Vol.34(No.1) 109-120, 2018

Sidestream in domestic wastewater treatment plants contains high concentration of ammonium, which increases nitrogen loading rate in the mainstream. The process for deammonification consisting of partial nitritation-anaerobic ammonium oxidation (ANAMMOX) and heterotrophic denitrification is an economical method of solving this problem. Currently, about 130 full-scale deammonification plants are fully operating around the world, but none is in Korea. In order to transfer the principal information about sidestream deammonification processes to researchers and operators, we summarized basic concepts, processes type, and key influence factors (e.g., concentration of nitrogen compounds, dissolved oxygen (DO), temperature, and pH). This review emphasis on the processes of single-stage sequencing batch reactor (SBR) deammonification, which are widely used as full-scale plants. Since simultaneous processes of partial nitritation, ANAMMOX and heterotrophic denitrification occur in a single reactor, the single-stage SBR deammonification requires appropriate control/monitoring strategies for several operating factors (DO and pH mostly) to achieve efficient and stable operation. In future, AB-process consisting of A-stage (energy harvesting from organics) and B-stage (ammonium removal without organics) will be applied to the wastewater treatment process. Thus, we suggest mainstream deammonification for B-stage connected with the sidestream deammonification as seeding source of ANAMMOX. We expect that many researchers will become more interested in the sidestream deammonification.

Anaerobic ammonium oxidation, Deammonification, Partial nitritation, Sidestream, Single-stage sequencing batch reactor

배효관 Hyokwan Bae

DOI:10.15681/KSWE.2017.34.1.121 Vol.34(No.1) 121-131, 2018

Domestic sewage treatment plants (STPs) consume about 0.5 % of total electric energy produced annually, which is equivalent to 207.7 billion Korean won per year. To minimize the energy consumption and as a way of mitigating the depletion of energy sources, the sewage treatment strategy should be improved to the level of “energy positive”. The core processes for the energy positive sewage treatment include A-stage for energy recovery and B-stage for energy-efficient nitrogen removal. The integrated process is known as the A/B-process. In A-stage, chemically enhanced primary treatment (CEPT) or high rate activated sludge (HRAS) processes can be utilized by modifying the primary settling in the first stage of sewage treatment. CEPT utilizes chemical coagulation and flocculation, while HRAS applies returned activated sludge for the efficient recovery of organic contents. The two processes showed organic recovery efficiencies ranging from 60 to 70 %. At a given recovery efficiency of 80 %, 17.3 % of energy potential (1,398 kJ/m³) is recovered through the anaerobic digestion and combustion of methane. Besides, anaerobic membrane bioreactor (AnMBR) can recover 85% of organic contents and generate 1,580 kJ/m³ from the sewage. The recovered energy is equal to the amount of energy consumption by sewage treatment equipped with anaerobic ammonium oxidation (ANAMMOX)-based B-stage, 810 ~ 1,620 kJ/m³. Therefore, it is possible to upgrade STPs as efficient as energy neutral. However, additional novel technologies, such as, fuel cell and co-digestion, should be applied to achieve “energy positive” sewage treatment.

Anaerobic membrane bioreactor, Chemically enhanced primary treatment, Energy positive sewage treatment, High rate activated sludge