The purpose of this study was to analyze water treatment characteristics, including the efficiency of removing algae from water purification plants, by installing a demonstration facility for decontamination of algae, including natural algae remover injection equipment, in the water purification plant. Jar-test showed that the optimum injection of natural decontaminant was 20 mg/L. Of the water contaminant treatment efficiency of the intake and water purification plants, Chl-a averaged 74.0% elimination efficiency from 5.0 mg/m3 to 1.3 mg/m3 and the maximum treatment efficiency was 91.5% removal efficiency when the inflow concentration of Chl-a was 11.8 mg/m3. In addition, 51.2% and 47.1% of the taste and odor indicator items, geosmin and 2-MIB, resulted from the overgrowth and decaying of algae, respectively, to identify toxic substances and odor reduction effects. In addition, elimination efficiencies of SS and Turbidity materials were higher than 70.0%. In the injection of natural algae remover, no effects such as sudden changes in water quality due to secondary reactions were found, and appropriate levels were maintained under water treatment conditions.

The purpose of this study was to analyze the effects of sewerage facilities through I/I analysis by rainfall by selecting areas where storm overflow diverging chamber is remained due to the non-maintenance drainage equipment when the sewerage system was reconstructed as a separate sewer system. Research has shown that wet weather flow(WWF) increased from 106.2% to 154.8% compared to dry weather flow(DWF) in intercepting sewers, and that the WWF increased from 122.4% to 257.6% in comparison to DWF in storm overflow diverging chamber. As a result, owing to storm overflow diverging chamber of partially separate sewer system with untreated tributary of sewage treatment plant, rainfall-derived infiltration/inflow(RDII) has been analyzed 2.7 times higher than the areas without storm overflow diverging chamber. Meanwhile, infiltration quantity of this study area was relatively higher than that of other study areas. Therefore, it is necessary to reduce infiltration quantity through sewer pipe maintenance nearby river. Drainage equipment maintenance should be performed not to operate storm overflow diverging chamber in order to handle the appropriate sewage treatment plant capacity for rainfall because it is also expected that RDII due to rain will occur after maintenance. In conclusion, it is necessary to recognize aRDII(allowance of rainfall-derived infiltration/inflow) and to be reflected it on sewage treatment plant capacity because aRDII can occur even after maintenance to the complete separate sewer system.

이 논문은 근대시 형성과정에 대한 두 가지의 의문으로 시작 했다. 첫째, 근대시의 형성과정은 개화가사→ 창가→ 신체시→ 자유시로 단계적인 이행을 거쳤을까? 둘째, 19세기말 찬송가의 유입은 창가처럼 노래를 전제한 시가(詩歌) 뿐만 아니라, 신체시와 자유시의 형성에도 상당하게 영향을 주었을까? 하는 것이었다. 사실 창가와 신체시는 서양의 선교사들이 중심이 되어 찬송가가 활발하게 번역되면서 개화기의 시가(詩歌)에 영향을 주게 되고, 이후 자유시의 태동에도 일정부분 영향을 끼친 것으로 생각된다. 이 글의 논점은 찬송가는 서양악곡을 기반으로 한 종교음악이었지만 번역과정을 통해 시적(詩的)인 형식과 새로운 문물에 대한 인식의 전환을 가져와서 근대시의 형성에도 영향을 준 것으로 보 았다. 최남선의 신체시는 그 가운데에 등장하게 된 것이며, 본고는 이를 갈등과 변화 속에서 탄생한 ‘메타모포시스 시학’으로 불러보고자 했다.

한국에 유입된 한자어는 국어화한 보통명사, 고유명사, 새로운 개념어, 그 외 개별 음역 차 용어로 나눌 수 있다. 이들 중 국어화한 보통명사는 한국 한자음으로 표기하고, 개별 음역 차 용어는 단어마다 특유의 독음법이 정착하였다. 반면 고유명사와 새로운 개념어는 한국 한자 음과 중국 원지음을 기반으로 한 표기라는 두 가지 독음 방법 사이에서 혼란을 겪고 있다. 한자는 다른 외국어와 달리 국어의 영역에 있었으나 현대에 와서 외국어로 인식되기 시작했다. 한자어의 독음에 대한 논쟁은 이러한 인식 차이에서 기인한다. 본 논문은 이러한 관점에 서 중국에서 유입된 한자어를 분류하고 그 독음 표기가 가지는 문화적 의미를 분석한다.

The red-eared slider (Trachemys scripta elegans) is the one of the most popular pets, and the most commonly traded species in the world. It is designated as an ecosystem disturbance species that has been managed in South Korea. To date, no reports of natural or anthropogenic migration and spreading of T. s. elegans in South Korea are available. In the present study, we estimated the expected route and the movable path of one female T. s. elegans found in Namsan-myun, Gyeongsan-si, Gyeongsangbuk-do. Based on the movable path, the potential destination of the female turtle was estimated to be about 282 m and 468 m away. Therefore, the moving distance of the red-eared slider to the nearest water system will be at least 606 m and at most 792 m. Our results provide the first evidence about the natural migration and spreading of exotic turtles. This study can serve as a basis for the management and countermeasures against the introduced of T. s. elegans and other exotic species in South Korea.

수영만 해역의 오염원 관리를 위해 유입되는 육상기인 오염물질의 체류특성을 분석하였다. 오염물질의 체류특성은 해수유동 모델과 입자추적 모델을 활용하여 분석하였다. 오염물질은 입자로 표현되며, 입자의 양과 오염물질량은 비례하도록 나타내었다. 체류특성은 각 오염원별로 부하량, 해역에서 체류하는 오염물질량, 부하량 대비 해역에 체류하는 오염물질량을 비교하여 분석하였다. 수영만 해역에 체류하고 있는 오염물질량을 오염원별 순으로 나타내면 수영하수처리장, 남부하수처리장, 수영강 등의 순이었다. 오염부하량이 적고 만 내측에서 멀어질수록 해역에 체류하는 오염물질량이 적었다. 오염원 중에서는 남부하수처리장에서 유입되는 부하량이 가장 많았다. 하지만, 유입 부하량 대비 해역에 체류하는 오염물질량은 수영만으로 유입되는 오염원 중 가장 낮은 값을 보였다. 이는, 해역의 특성과 각 오염원의 지형적인 특성에 따라 오염물질이 해역에 미치는 정도가 다르다는 것을 의미한다.

To ensure the safety and functionality of a railroad bridge, maintaining the integrity of the bridge via continuous structural health monitoring is important. However, most structural integrity monitoring methods proposed to date are based on modal responses which require the extracting process and have limited availability. In this paper, the applicability of the existing damage identification method based on free-vibration reponses to time-domain deflection shapes due to moving train load is investigated. Since the proposed method directly utilizes the time-domain responses of the structure due to the moving vehicles, the extracting process for modal responses can be avoided, and the applicability of structural health evaluation can be enhanced. The feasibility of the presented method is verified via a numerical example of a simple plate girder bridge.

The annual total phosphorus load caused by public wastewater, nightsoil and livestock manure treatment facilities in Korea has been examined macroscopically. Annual domestic average phosphorus (P) inflows through the income of phosphate rock for the last five years (2012 - 2016) were analyzed as 76,598 tons/year. As of the year 2015, the total loadings of phosphorus attributed to public wastewater treatment facilities, nightsoil treatment facilities and livestock wastewater were estimated as 30,269 tons/year, 1,909 tons/year and 18,138 tons/year, respectively. Considering the amount of phosphorus imports, the annual phosphorus load from wastewater, livestock wastewater and excretions is equivalent to 39.5%, 23.7%, 2.5% and totally 65.7%(39.5% + 23.7% + 2.5%). Therefore, the introduction of phosphorus recovery and recycling processes for the public wastewater and livestock manure treatment facilities has been found to be effective because it could reduce the import amount of phosphate rock by up to 60% or more.

Membrane distillation (MD) is a thermally driven desalination process with a hydrophobic membrane. MD process has been known to have a lower fouling potential compared to other pressure-based membrane desalination process (NF, RO). However, membrane fouling also occurs in MD process. In this study, the membrane fouling was observed in MD process according to the pre-treatment processes. The filtration and precipitation processes were applied as the pre-treatment to prevent the membrane fouling. The pore sizes of roughing filters were 0.4, 5, 10, 30, and 60 ㎛. The concentration of the coagulant was 1.2 mg/L as FeCl3. The membrane fouling on MD membrane was successfully removed with both pre-treatment processes.

서울시 한강으로 유입되는 하천의 어류군집 특성 분석을 위해 2016년 5월부터 2017년 4월까지 조사하였다. 자연형으로 복원된 하천은 우이천, 당현천, 청계천, 양재천, 목감천, 도림천, 홍제천 등이다. 조사 기간 동안 21개 지점에서 족대와 투망으로 채집된 어류는 총 10과 41종이었다. 한반도 고유종에 속하는 어종은 줄납자루(Acheilognathus yamatsutae), 가시납지리(Acheilognathus gracilis), 중고기(Scrcocheilichthys nigripinnis morii), 몰개(Squalidus japonicus coreanus), 참갈겨니(Zacco koreanus), 꺽지(Coreoperca herzi), 얼룩동사리(Odontobutis interruta) 등 7종 이었으며 고유화빈도가 17.1%이었다. 국외에서 도입된 외래종은 비단잉어(Cyprinus carpio, Fancy type), 금붕어 (Carassius auratus, Gold fishh), 떡붕어(Carassius cuvieri), 블루길(Lepomis macrochirus), 배스(Micropterus salmoides) 등 5종(12.2%)이었다. 각 조사 지점별 우점종은 피라미(Zacco platypus), 붕어(Carassius auratus), 납자루 (Acheilognathus lanceolatus), 가시납지리(Acheilognathus gracilis), 대륙송사리(Oryzias sinensis) 등이었다. 종다양도 지수, 균등도지수 및 종풍부도 지수에서 양제천이 다른 조사 하천에 비해 지수가 높아 안정적인 군집 상태를 나타내었 다. 수질에 대한 내성도 guild에서 민감종이 3종(7.3%), 중간종 16종(39.0%), 내성종 22종(53.7%)이었다. 식성에서 충식성은 12종(29.3%), 잡식성 23종(56.1%), 육식성 6종(14.6%)으로 잡식성이 매우 풍부하였다.

정삼투막(Forward osomosis, FO) 공정은 차세대 해수담수화 기술 중 하나이 다. FO 공정은 운영에너지나 막오염의 장점에도 불구하고 유도용액의 분리회수 등의 문제로 실증화 단계에 어려움이 있다. 따라서 현재 FO 공정에 대해서는 FO를 단독으로 사용하기보다 RO 전단에 FO 공정을 두어 이용하는 hybrid 시스 템으로 이용하려는 연구가 많이 진행되고 있다. 본 연구는 유도용액의 분리회수 가 필요하지 않은 FO-RO 공정에서의 성능 지표 중 하나인 투과유량을 늘리기 위해 공정 운전 조건 중 유도용액의 유량변화에 따른 성능을 평가하였다.

In this study, the effect of chemically enhanced backwash(CEB) coping with algal(Heterosigma Akashiwo) inflow was evaluated in the seawater desalination pretreatment process using ceramic membrane. In order to confirm the possibility of long-term filtration operation, the recovery rate of transmembrane pressure(TMP) due to the CEB using NaOCl was examined. When the membrane flow rate was 83.3 LMH, the TMP was maintained within 200 kPa for 84 hours in seawater influent. As the algal counts of 30,000 cell/mL were injected into the influent of seawater, however, the TMP rapidly increased and exceed maximum value. Membrane fouling caused by the algae was very poorly recovered by usual physical backwash. The CEB was performed for 30 min(3 min circulation / 27 min immersion) with 300 mg/L of NaOCl. As a result of the CEB application, it was possible to maintain a stable operating of filtration during 10 days and the average recovery rate of TMP by the CEB was 98.1%. It has been confirmed that the CEB using NaOCl is very effective in removal of membrane fouling by algae, resulted in stable membrane filtration for the long-term operation.

In this study, the effects of operating conditions on the formation of reversible and irreversible fouling were investigated in the filtration using ceramic membrane for water treatment process. The effect of coagulation pretreatment on fouling formation was also evaluated by comparing the performance of membrane filtration both with and without addition of coagulant. A resistance-in-series-model was applied for the analysis of membrane fouling. Total resistance (RT) and internal fouling resistance (Rf) increased in the membrane filtration process without coagulation as membrane flux and feed water concentrations increased. Internal fouling resistance, which was not recovered by physical cleaning, was more than 70% of the total resistance at the range of the membrane flux more than 5 m3/m2･day. In the combined process with coagulation, the cake layer resistance (Rc) increased to about 30-80% of total resistance. As the cake layer formed by coagulation floc was easily removed by physical cleaning, the recovery rate by physical cleaning was 54~90%. It was confirmed from the results that the combined process was more efficient to recover the filtration performance by physical cleaning due to higher formation ratio of reversible fouling, resulted in the mitigation of the frequency of chemical cleaning.

본 연구에서는 막결합생물반응조(MBR)공법을 비롯한 하수고도처리공법에서 유입하수량의 변화에 따른 슬러지 특성 변화를 파악하고자 하였다. 일 1.5톤을 처리하는 모형실험시설에서 설계유량 대비 유입하수량을 100, 70, 40, 10%로 변 화시켜가며 이에 따른 비탈질속도(specific denitrification rate)와 비질산화속도(specific ammonia oxidation rate)의 변화를 측 정하였다. 각 공법의 폭기조에서 채취한 슬러지의 비질산화속도는 유입하수량 100% 조건에서 세 가지 공법 모두 유사한 값 (0.10 gNH4/gMLVSS/day)으로 측정되었다. 유입하수량이 70%에서 40%로 감소함에 따라 비질산화속도가 크게 감소하는 경향을 나타냈다. 비탈질속도 역시 유입하수량이 감소함에 따라 최대 50%가량 감소하였다. 유입하수량이 감소할수록 비탈질속 도와 비질산화속도가 감소하는 경향을 나타냈으나 원수의 총질소 농도와 반응조 내 미생물 농도를 고려하면 질소제거율에 영향을 미칠 정도는 아니었다. 따라서 유입하수량이 감소하는 경우에도 반응조 내 미생물 농도를 높게 유지할 수 있다면 안정적인 질소 제거가 가능할 것으로 판단된다.

In this study, the fauna of freshwater fish were investigated from March until October of 2016 in 24 independent streams in the Jeonnam and Jeonbuk provinces, which were flowing into the Yellow Sea. The health of the aquatic ecosystem in those streams was assessed through the biological and abiological character index (BAc index). During the surveyed period, a total of 4,127 individuals were collected; they belonged to 59 species of 44 genera in 18 families. The most dominant species identified was Zacco platypus, and 12 species were endemic species of Korea, including Rhodeus uyekii. The BAc index indicated a statistically significant correlation (p<0.01 or 0.05). The stage distribution of the aquatic ecosystem health assessment showed the highest rating of 41.7% at the “Fair” stage. The “Good” and “Poor” stages accounted for 20.8% while the “Excellent” stage took up 16.7%. It has been confirmed that the aquatic ecosystem health of independent streams is influenced more by the abiological character index as a consequence of geographical characteristics and artificial/natural limiting factors, than by the biological character index.

베트남은 한(漢)나라 때부터 약 1천 년 간 중국의 속국으로서 통치를 받는 동안 정치, 행 정, 경제, 문화, 교육, 예술 등 모든 분야에서 한자를 사용했고, 중국으로부터 독립한 이후에도 베트남의 대부분 봉건왕조는 한자를 공식문자로 지정해 공문서를 한자로 작성, 기록했다. 뿐만 아니라, 봉건왕조 시기에는 유교를 통치 이념으로 도입하여 베트남 사회에 한자 숭배 사상과 유교사상 또한 깊이 뿌리내리게 했다. 본 논문에서는 한자의 베트남으로 유입, 발전, 쇠퇴의 과정을 시대별로 살펴봄으로써 한자가 베트남의 언어문화에 초래한 영향의 정도와 그 추이를 이해하고자 한다.