• 생태와환경
• /
• 제40권2호
• /
• pp.254-263
• /
• 2007

본 연구에서는 낙동강 수계의 본류에 해당하는 6개 지점을 선정하여 2004년 7월(풍수기), 2005년 3월(갈수기), 2회에 걸쳐 생물학적 건강도 지수(Index of Biological Integrity, IBI), 정성적 서식지평가지수(Qualitative Habitat Evaluation Index, QHEI) 분석 및 이화학적 수질분석을 통해 통합적 하천 생태 건강성 평가를 실시하였다. 생태 건강성 평가를 위한 생물통합지수 모델은 국내 특성에 맞게 수정 보완된 10개 다변수 메트릭 모델(Multimetric model)을 이용하였고, 물리적 서식지 지수인 QHEI는 국내 하천 특성에 맞게 변형한 11개의 다변수 메트릭 모델을 적용하였다. 낙동강의 생물통합지수는 평균 20.8(n=12)로 "악화상태" (Poor)를 나타냈으며, 각 지점에서 전반적으로 낮은 생태학적 건강도 값을 나타냈다. 이는 이화학적 수질 악화와 물리적 서식지의 교란으로 인해 수체 내의 생물에게 직접적인 영향을 끼친 것으로 사료되었다. 물리적 서식지평가지수인 QHEI의 전 지점에 대한 평균값은 110으로 "보통${\sim}$양호상태" (Fair${\sim}$Good)를 보였다. 지점별 분석에 따르면, 1, 5지점은 양호상태(Good)를 보였고, 나머지 4개 지점에서는 모두 보통상태 (Fair)를 보였다. 그러나 3,4지점은 보통${\sim}$악화 (Fair${\sim}$poor)에 가까운 상태를 보여 서식지의 교란이 큰 것으로 판단되었으며, 특히 $M_1{\sim}M_5$, $M_7$, $M_{10}$에서 매우 악화된 상태를 보여 향 후 메트릭에 대한 복원이 필요할 것으로 사료되었다. 이화학적 수질은 3지점에서 금호강의 유입과 인근에 위치한 분뇨처리시설의 직접적인 영향으로 인해 크게 악화되었다. 낙동강의 하류에 해당하는 4, 5, 6지점은 남강과 황강의 유입에 의한 희석효과 및 생물학적 자정작용에 의해 수질이 개선되거나 일정농도를 유지하는 것으로 나타났다.

• 대한환경공학회지
• /
• 제34권3호
• /
• pp.195-203
• /
• 2012

재질별 생물활성탄(BAC) 및 안트라사이트 biofilter에서 EBCT 및 수온변화에 따른 인공사향물질(SMCs) 3종의 생물분해 특성을 조사한 결과 다음과 같은 결론을 얻을 수 있었다. 생물활성탄(BAC) 공정에서 인공사향물질 3종의 제거는 EBCT와 수온에 따라 큰 영향을 받으며, EBCT와 수온이 증가할수록 제거능이 증가하였다. 물질에 따른 제거능은 MK가 가장 높았고 다음으로 HHCB, AHTN 순이었다. 또한, 활성탄 재질에 따른 생물활성탄(BAC) 및 안트라사이트 biofilter에서의 인공사향물질 3종의 제거는 석탄계 재질의 BAC에서 생물분해능이 가장 높았고, 다음으로 목탄계, 야자계, 안트라사이트 순으로 조사되었다. 인공사향물질 3종에 대한 생물분해 속도상수($K_{biodeg}$)와 반감기($t_{1/2}$)는 수온이 $5{\sim}25^{\circ}C$일 때 0.0082~0.4452 $min^{-1}$와 1.56~84.51 min이었으며, 수온이 $15^{\circ}C$와 $25^{\circ}C$로 증가시켰을 때 $5^{\circ}C$에서의 반감기보다 3.1~9.3배 감소되었다.

• 대한환경공학회지
• /
• 제36권11호
• /
• pp.739-746
• /
• 2014

생물활성탄(BAC)과 안트라사이트 biofilter에서의 공탑 체류시간(EBCT) 및 수온의 변화에 따른 8종의 자외선 차단제들의 생물분해 특성을 평가하였다. 수온 $7^{\circ}C$와 $18^{\circ}C$에서 EBCT를 5분~15분까지 변화시켜 실험하였다. 생물활성탄 공정에서 자외선 차단제 8종의 생물분해율은 EBCT와 수온에 따라 큰 영향을 받았으며 EBCT와 수온이 증가할수록 생물분해율이 증가하였으며, 자외선 차단제들의 종류에 따른 생물활성탄 공정에서의 생물분해율은 EHMC와 BZC가 가장 높았으며, BP와 4-MBC가 가장 낮았다. 자외선 차단제 8종에 대한 BAC 공정에서의 생물분해 속도상수($k_{bio}$)는 수온이 $7^{\circ}C$에서 $18^{\circ}C$로 상승하였을 경우, $0.2730{\sim}0.6365min^{-1}$에서 $0.4824{\sim}0.8743min^{-1}$로 증가하여 1.5~2.1배 정도 증가하였다.

• 상하수도학회지
• /
• 제14권1호
• /
• pp.108-116
• /
• 2000

Chlorine is widely used as a disinfectant in drinking-water systems throughout the world. Chlorine residual was used as an indicator for prediction of water quality in water distribution systems. The variation of chlorine residual in drinking water distribution systems of Suwon city was simulated using EPANET. EPANET is a computerized simulation model which predicts the dynamic hydraulic and water quality behavior within a water distribution system operating over an extended time period. Sampling and analysis were performed to calibrated the computer model in 1999 (Aug. Summer). Water quality variables used in simulations are temperature, roughness coefficient, pipe diameter, pipe length, water demand, velocity and so on. Extended water residence time affected water quality due to the extended reaction time in some areas. All area showed the higher concentration of chlorine residual than 0.2mg/l(standard). So it can be concluded that any area in Suwon city is not in biological regrowth problem. Rechlorination turned out to be an useful method for uniform concentration of free chlorine residual in distribution system. The cost of disinfectant could be saved remarkably by cutting down the initial chlorine concentration to the level which guarantees minimum concentration (0.2mg/l) throughout the distribution system.

• 한국농공학회논문집
• /
• 제64권6호
• /
• pp.1-12
• /
• 2022

Estuary reservoirs were artificial reservoir with seawalls built at the exit points of rivers. Although many water resources can be saved, it is difficult to manage due to the large influx of pollutants. To manage this, it is necessary to analyze watersheds and reservoirs through accurate modeling. Therefore, in this study, we linked the Hydrological Simulation Program-FORTRAN (HSPF), Environmental Fluid Dynamics Code (EFDC), and Water quality Analysis Simulation Program (WASP) models to simulate the hydrology and water quality of the watershed and the water level and quality of estuary lakes. As a result of applying the linked model in stream, R² 0.7 or more was satisfied for the watershed runoff except for one point. In addition, the water quality satisfies all within 15% of PBIAS. In reservoir, R² 0.72 was satisfied for water level and the water quality was within 15% of T-N and T-P. Through the modeling system, We applied upstream pollutant management scenarios to analyze changes in water quality in estuary reservoirs. Three pollution source management were applied as scenarios, the improvement of effluent water quality from the sewage treatment plant and the livestock waste treatment plant was effective in improving the quality of the reservoir water, while the artificial wetland had little effect. Water quality improvement was confirmed as a measure against upstream pollutants, but it was insufficient to achieve agricultural water quality, so additional reservoir management is required.

• Ocean and Polar Research
• /
• 제44권1호
• /
• pp.13-27
• /
• 2022

The Yeongsan River estuary was altered by a sea dike built in 1981 and the sluice gates in the dike were extended recently in 2014. The construction has caused changes in water properties and hydrodynamics and also produced disturbances including hypoxia and algal blooms. We analyzed the water quality and chlorophyll-a data (2009-2018) collected seasonally at 3 stations (Sts. 1-3) along the channel of the estuary by the Marine Environmental Monitoring System. Variations in water quality and chlorophyll-a (an index of phytoplankton biomass) were examined and their stressors were also identified by statistics including correlation and multivariate principal component analyses (PCA). The water quality was mainly affected by freshwater discharge from the dike. Salinity, nutrients and chlorophyll-a were especially affected by the discharge and the effect enhanced during summer and at the upper region near the sea dike decreasing downstream. Three factors were extracted for each station in the PCA accounting for 66.07-72.42% of the variations. The first was an external factor associated with freshwater discharge and the second and third were seasonal or biological factors. The results indicate that the water quality is more affected by short-termed and episodic events such as freshwater discharge than seasonal events and the influence of freshwater discharge on water quality is more extensive than that previously reported. This suggests that the boundary of the estuary should be extended to take into account the findings of this study and a management strategy linked to the freshwater zone is required to manage the integrity and water quality of the Yeongsan River estuary.

• 생태와환경
• /
• 제42권2호
• /
• pp.212-220
• /
• 2009

본 연구는 2008년 11월에 마산저수지를 대상으로 어류 종조성 및 섭식길드 및 오염내성길드에 따른 생태지표 특성을 분석하고, 이와 연관된 화학적 수질 특성 변화를 분석하였다. 채집된 어류는 총 12종(6과)으로 나타났고, 주요 우점종은 피라미, 치리, 참붕어 등으로 나타났다. 한국 고유종은 3종만이 출현하였으며, 외래도입종은 떡붕어 1종이 출현하였다. 생태지표 특성 분석에 따르면, 내성종 및 잡식종의 상대풍부도는 각각 98%로 단연 우점하는 것으로 나타나, 이화학적 질적저하 및 물리적 서식지 교란요인에 의한 영향을 반영하고 있었다. 호안에 따른 종분포 특성 분석 결과, 정수식물이 발달한 호안에서 대부분의 어류가 95% 이상이 채집된 것으로 나타났다. 또한 하상 기질 특성에 따른 분석 결과, 뻘(Silt)로 된 구간에서 가장 많은 종 (11종, 91.7%)이 채집되어, 하상기질에 따라 유의한 차이를 보이고 있었다. 화학적 수질자료 분석에 따르면, 호수 영양상태 지표인 총인(TP) 및 Chl-a의 농도는 모두 과영양상태인 것으로 나타났으며, 호수의 유기물오염의 지표로 사용되는 COD도 평균 10.9 mg $L^{-1}$로 나타났다. 마산저수지의 이러한 수질저하는 어류의 섭식구조(잡식종의 증가) 및 내성종의 증가 등을 통해 반영되었다. 향후 마산저수지의 어류상 및 어류 종조성이 향상을 위해서 수질 개선 및 서식지 복원이 펼요할 것으로 사료된다.

• 생태와환경
• /
• 제42권4호
• /
• pp.452-464
• /
• 2009

The objectives of this study were to evaluate spatial and temporal variability of water quality in 10 reservoirs and identify the key nutrients (N, P) influencing chlorophyll-a (CHL) along with analysis of empirical models and zonal patterns of total phosphorus (TP) and CHL. We analyzed total nitrogen (TN), TP, CHL, water clarity (Secchi depth, SD), and evaluated potential limiting nutrient using ambient N:P ratios and previous criteria of ambient nutrients. Water clarity and CHL varied largely depending on the seasonal monsoon and type of reservoir, but trophic state was diagnosed as eutrophy, base on mean CHL in most reservoirs. The peak of TP did not match the contents of CHL due to rapid flushing during the high run-off period. In the reservoir of DR, regression coefficient in the $P_r$ was 0.510 but was 0.159 in the $M_o$, while the TP-CHL relation in the YR increased during the monsoon compared to the premonsoon. The regression coefficient in the $P_r$ was not statistically significant but the value of $M_o$ was 0.250. TP showed similar longitudinal zonal gradients among the reservoirs of DR, YR and JR. Empirical models of TP-CHL, based on overall data, showed that CHL was determined by phosphorus($R^2=0.244$, p=0.0019). Regression analysis of CHL-SD showed a stronger linear fit ($R^2=0.638$, p<0.001) than the TP-CHL model.

• 한국물환경학회지
• /
• 제25권3호
• /
• pp.394-403
• /
• 2009

A total of 52 sampling sites were selected in the stream network of the upper Paldang watershed (e.g. Kyonan, Gapyeong, Jojong, Chengmi, Bockha, Yanghwa and Heuk streams). Over the time period of April 2007-February 2008, 1820 samples were collected and analyzed for physico-chemical variables of the upper watershed in order to investigate spatio-temporal water quality variation in particular the relationship with land use. Although temporal variations of water quality in each stream were similar and were significantly influenced by flow, spatial variations in each stream varied as physico-chemical characteristics of upper watershed. As a result of regression analysis, Biological Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Total Nitrogen (T-N), and Total phosphorus (T-P) concentration were the most significantly and positively associated with people population density. It is necessary to manage not only water quality but also land use of upper watershed and flow flux.

• 환경위생공학
• /
• 제18권2호
• /
• pp.16-26
• /
• 2003

Analysis of benthic macroinvertebrate community and biological estimation of water quality was conducted at the national park of Mt. Jiri and its nearby area in Gurye, Sancheong and Hadong-gun from June to November, 2002. Total taxa of benthic macroinvertebrates were 124 species, 45 families, 15 orders, 5 classes in 3 phyla. Aquatic insects were 33 species in ephemeroptera, 28 species in Trichoptera, 21 species in plecoptera, 13 species in Diptera, 8 species in odonata, 5 species in hemiptera and 5 species in coleoptera, respectively. Non-insects were 5 species in Mollusca, 2 species in Hirudinea, 1 species in oligochaeta and 1 species in crustacea, respectively. Ephemeroptera, trichoptera and plecoptera as indicators in clean water were very abundant. Occurrence species at each survey area was 68 species at Mt. 1025-goji, 59 species at Mt. Eungseok-bong, 57 species at Mt. Wangdeung-jae, 50 species at Mt. Cheonwang-bong and 39 species at Mt. 645-goji, respectively. Mean species diversity indices at Mt. Cheonwang-bong, Mt. 1025-goji, Mt. Wangdeung-jae, Mt. Eungseok-bong and Mt. 645-goji were 3.33, 3.03, 3.41, 3.02 and 2.91, respectively, According to the saprobic system based on the species diversity indices of benthic macroinvertebrates, most survey areas except some sites are determined as Limnosaprobic area.