In recent years there have been large increases in the hydraulic loading rates used to design dissolved air flotation (DAF) facilities for drinking water applications. High rate DAF processes are now available at loading rates of 20 to 40 m3/m2·h. This research evaluated dissolved air flotation as a separation method for algae and organic compounds from water treatment plants. During the service period of 2016. 5. to 2017. 6., DAF pilot plants (500 m3/day) process has shown a constantly sound performance for the treatment of raw water, yielding a significantly low level of turbidity (DAF treated water, 0.21～1.56 NTU). As a result of analyzing the algae cell counts in the influent source, it was expressed at 100-120 cells/mL. In DAF treated water, the removal efficient of alge cell counts was found to be upto 90%. The stable turbidity and algae removal were confirmed by operating the high rate DAF process under the condition of the surface loading rate of 30 m3/m2·hr.

국내에서 다양한 농작물에 경제적 피해를 야기하는 미국선녀벌레는 나무 가지 틈에 산란하기 때문에 콩에서발생하는 피해는 포장 인근의 나무에서 포장내로 유입되어 발생한다. 이번 연구는 투명점착트랩을 3개 지역(연천,안성, 진천) 콩 포장 둘레에 설치 후 포획된 약충의 마릿수를 측정하여 진행되었으며, 그 결과를 이용하여 미국선녀벌레1령 약충이 월동처에서 콩 포장쪽으로 확산하는 모델을 개발하였다. 추가적으로 트랩 외부의 유입 개체와 트랩내부에 부착된 유출 개체수를 계산하여 포장 내 개체군의 밀도가 최대가 될 때까지의 발생 모델을 개발하였다.미국선녀벌레 1령 약충의 확산 모델과 포장내로의 유입 모델 모두 측정된 데이터를 잘 설명하였다(r2=0.99). 이번연구 결과들은 미국선녀벌레의 발생 동태를 예측하고 방제 전략을 구축하는데 기여할 수 있을 것으로 생각된다.

Thermal effluent of the hot spring has long been a field of interest in the relationship between temperature gradient and freshwater algae in geology, limnology and aquatic ecology throughout the world. On the other hand, many artificial hot springs have been developed in Korea, but the research on them has not been still active. This study was performed every month from December 2015 to September 2016, to elucidate the spatiotemporal effects of thermal wastewater effluent (TWE) on the ecosystem of benthic algal assemblage in four stations (BSU (upstream), HSW (hot spring wastewater outlet), BSD1~2 (downstream)) of the upstream reach of the Buso Stream, a tributary located in the Hantan River basin. During the survey, the influencing distance of temperature on TWE was <1.0 km, and it was the main source of N·P nutrients at the same time. The effects of TWE were dominant at low temperature and dry season (December~March), but it was weak at high temperature and wet season (July~September), reflecting some seasonal characteristics. Under these circumstances, the attached algal communities were identified to 59 genera and 143 species. Of these, the major phylum included 21 genera 83 species of diatoms (58.0%), 9 genera 21 species of blue-green algae (14.7%) and 25 genera 32 species of green algae (22.4%), respectively. The spatiotemporal distribution of them was closely related to water temperature (5℃ and 15℃) and current (0.2 m s-1 and 0.8 m s-1). In the basic environment maintaining a high water temperature throughout the year round, the flora favoring high affinity to PO4 in the water body or preferring stream habitat of abundant NO3-PO4 was dominant. As a result, when compared with the outcomes of previous algal ecology studies conducted in Korea, the Buso Stream was evaluated as a serious polluted state due to persistent excess nutrient supply and high thermal pollution throughout the year round by TWE. It can be regarded as a dynamic ecosystem in which homogeneity (Summer~Autumn) and heterogeneity (Winter~Spring) are repeated between upstream and downstream.

In a PEMFC gas channel with a trapezoidal cross-section, the effect of air and water inlet velocities on water removal characteristics is numerically studied via the volume of fluid(VOF) method. When the channel wall contact angle is 60 degrees, the air inlet velocities higher than 2.5 m/s are advantageous to obtain lower GDL surface water coverage ratio(WCR). The WCR increases as the wall contact angle increases to 90 or 120 degrees due to the relatively lower surface tension force. In overall, WCR decreases as the air inlet velocity increases and WCR increases as the water inlet velocity increases.

안동댐 내 저수지 및 유입 하천 6개 지점에 대하여 2016년 7월과 9월, 총 2회에 걸쳐 저서성 대형무척추동물 조사를 수행하였다. 분류군별 출현현황은 저수지 수변부(L1, L2, L3)와 유입 하천(S1, S2, S3)에서 각각 총 9목 31종, 14목 79종이 출현하였다. 군집지수 분석결과, 평균 다양도지수(H')와 균등도지수(J')는 S1에서 각각 3.04와 0.73으로 가장 높았으며, 평균 풍부도지수(R')와 우점도지수(DI)는 각각 S2(2.84), L3(0.98)에서 가장 높게 나타났다. 섭식기능군(FFG) 분석결과, 종수 점유율은 저수지에서 P(Predator)가 41.9%, 유입 하천에서 GC(Gathering Collector)가 30.4%로 가장 높게 나타났다. 서식기능군(FHG) 분석결과, 비교적 유수역을 선호하는 CL(Clinger)의 종수점유율이 유입 하천에서 43.0%로 저수지의 32.3%보다 더 높게 나타났다.

안동⋅임하 유입지천의 저서성대형무척추동물의 군집안정성 분석을 위해 4개 지점(St.1, St.2, St.3, St.4) 선정 후 2016년 5월부터 9월까지 총 4회 조사를 실시하였다. 총 5문 8강 18목 56과 108종 53,368.8개체가 조사되었고, 안동호(St.1, St.2)는 총 4문 6강 14목 49과 82종 31,253.9개체, 임하호(St.3, St.4)는 총 5문 7강 17목 50과 83종 22,114.9개체 가 조사되었다. 전체 출현 분류군 중 하루살이목이 안동호 17종(20.7%), 임하호 16종(19.3%)으로 가장 많은 종수비율을 차지하였다. 출현 저서 동물을 대상으로 군집분석을 실시한 결과 안동호의 평균 우점도지수는(DI) 0.66 평균 다양도지 수(H') 2.39 평균 풍부도지수(R1) 2.47 평균 균등도지수(J') 0.55로 나타났다. 임하호의 평균 우점도지수는 0.59, 평균 다양도지수 2.69, 평균 풍부도지수 2.61, 평균 균등도지수 0.62로 나타났다. 군집안정성분석 결과 두 수계 모두‘I’그룹(저 항력↑, 회복력↑)에 속하는 종들의 출현율이 안동호 66.2%, 임하호 62.5%로 가장 높게 나타났다.

본 연구는 2000년 중반이후 특히 2006년부터 중국의 가공무역 제한조치가 확대되고, 제11 차 5개년 규획(2006-2010년)에 따라 자국의 소재 및 부품산업을 육성하고자하는 정책이 본격 적으로 시행됨으로써 기존의 해외직접투자유입과 수입 간의 관계가 계속해서 성립하는지 실 증분석을 통해 규명하고자 하였다. 이에 1993-2014년까지의 총 연구기간을 1993-2005년까지 와 2006-2014년까지로 나누어 분석하였고, 보다 엄밀한 분석을 위해서 수입을 중간재 수입, 최종재 수입, 총 수입으로 세분화하여 분석하였다. 먼저 1993-2005년 기간 동안의 분석결과 중국의 해외직접투자유입의 증가는 중간재 수입과 총 수입을 증가시켰다. 하지만 2006-2014 년 기간 동안의 분석결과 중국의 해외직접투자유입의 증가는 오히려 중간재 수입을 감소시켰 다. 이러한 결과는 이전 기간의 분석결과와 완전히 상반된 것으로 2006년부터 강화된 일련의 정책들로 인해 해외직접투자유입의 증가와 동반되던 중간재 수입의 증가가 더 이상 통용되지 않는다는 것을 의미한다.

Benthic macroinvertebrates were investigated in thermal discharge that flows Buso stream region from December 2015 to February 2016, Korea. Study site was selected for the upstream, downstream relative to the mixing station and mixing station which thermal effluent flows, water quality analysis and benthic macroinvertebrates composition, taxa of EPT-group individuals, analysis of biological water quality. As a result, a total of 4,015 individuals including 50 species, 30 families, 11 orders, 4 classes, and 3 phyla were recognized. Taxa of species is Ephemeroptera 16 species (32.0%) including 6 families, the density composition was highest in 1,848 individuals (46.03%) Diptera. EPT-group occupied during the study period were a total of 1,876 individuals (46.72%) including 32 species and 17 family, lowest in the mixing station for study period. As a results of community analysis, mixing station in the Limnodrilus gotoi and Chironomidae sp.2, which is dominated by the analysis was Ecdyonurus levis, Cincticostella levanidovae, Nemoura KUa. The dominant species showed a difference in the upstream and downstream. In the functional feeding groups, in the upstream and mixing station Gathering-Collectors, downstream it was analyzed that the ratio of the highest Filtering-Collectors and decreased the ratio of Shredders increasing from upstream to downstream. Habitat orientation group is analyzed that accounted for most of the Clingers and Burrowers, from upstream to downstream toward the higher the ratio of Clingers. Biological water quality assessment results were analyzed the worst state in the mixing station with an average 2.73 (±0.41). Correspondence analysis, correlation analysis results of water temperature and the cold-water species, as the water temperature increases were analyzed by reducing cold-water species and EPT-group.

Euiam and Paldang Reservoirs have often been facing water quality problems, such as eutrophication, algal blooms and off-flavors by treated wastewater effluent (TWE) in the North-Han and the Han River basins, but little is examined on the direct biological effect of TWE. This study tested algal growth potential (AGP) of four TWEs discharged into Euiam and Paldang Reservoirs to evaluate water fertility in September 2014 and March and September 2015. Test alga was used Anabaena circinalis isolated from Paldang Reservoir. Mean concentration of T-N and T-P in TWEs was 3,956.7 μg N L-1 and 50.8 μg P L-1, and the proportion of NO3-N and PO4-P to the total fraction was 72.1% and 40.8%, respectively. Both N and P were high in TWEs, but much higher N than P concentration indicates strong P-limitation. As a consequence, the maximum AGP was determined by PO4-P concentration (r=0.998, p<0.01). Mean AGP value was 15.4 mg dw L-1 among four effluents indicating its eutrophic condition. Due to the establishment of tertiary (advanced T-P) treatment method in the studied plants recently, P concentration was significantly decreased in TWEs compared to the years prior to 2012. However, P concentration seems to be still high enough to cause eutrophication and algal blooms. Therefore, wastewater treatment to P-free level needs to be considered if effluents are directly discharged into the drinking water resources.

A membrane bioreactor by sequentially alternating the inflow and by applying a two-stage coagulation control based on pre-coagulation was evaluated in terms of phosphorus removal efficiency and cost-savings. The MBR consisted of two identical alternative reaction tanks, followed by aerobic, anoxic and membrane tanks, where the wastewater and the internal return sludge alternatively flowed into each alternative reaction tank at every 2 hours. In the batch-operated alternative reaction tank, the initial concentration of nitrate rapidly decreased from 2.3 to 0.4 mg/L for only 20 minutes after stopping the inflow, followed by substantial release of phosphorus up to 4 mg/L under anaerobic condition. Jar test showed that the minimum alum doses to reduce the initial PO4-P below 0.2 mg/L were 2 and 9 mol-Al/mol-P in the wastewater and the activated sludge from the membrane tank, respectively. It implies that a pre-coagulation in influent is more cost-efficient for phosphorus removal than the coagulation in the bioreactor. On the result of NUR test, there were little difference in terms of denitrification rate and contents of readily biodegradable COD between raw wastewater and pre-coagulated wastewater. When adding alum into the aerobic tank, alum doses above 26 mg/L as Al2O3 caused inhibitory effects on ammonia oxidation. Using the two-stage coagulation control based on pre-coagulation, the P concentration in the MBR effluent was kept below 0.2 mg/L with the alum of 2.7 mg/L as Al2O3, which was much lower than 5.1∼7.4 mg/L as Al2O3 required for typical wastewater treatment plants. During the long-term operation of MBR, there was no change of the TMP increase rate before and after alum addition.

In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on “Water Quality Monitoring Networks” in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.

It is known that air pollutants such as fine dust and exhaust gas from vehicles are harmful to human health. In particular, the black carbon emitted by vehicles is known to cause a large number of premature deaths. This study analyzed the effect of a noise barrier on the inflow amount of black carbon from a nearby high traffic road to a school area, using numerical analysis performed at two elementary schools. Also, the correlation between the noise barrier’s shape, height and the inflow amount of black carbon was assessed. As a result, it was found that the higher the noise barrier, the lower the inflow amount of black carbon observed at the school A. However, the inflow amount of black carbon at school B was not greatly influenced by the height of the noise barrier. The inflow amount of black carbon at the schools could be changed not only by the height of the noise barrier, but also by the shape, height and position of the noise barrier and the school building.

This study was conducted to provide important basic information about effective management of the marine environment at major inflow streams in Lake Andong and Lake Imha. The investigation was conducted 8 times from May, 2015 (AD1, AD2, IH1, IH2) to September, 2016 (AD3, AD4, IH3, IH4), and 8 surveyed sites were selected at Lake Andong (4 sites) and Lake Imha (4 sites). The inquiry identified 114 species, 59,913.7 inds. m-2 in Lake Andong and 112 species, 39,038.4 inds. m-2 in Lake Imha. The results indicate that the number of species and individuals in Lake Andong is more than that in Lake Imha, because Lake Andong has a variety of riparian vegetation and a richness of organic materials. Community analysis at Lake Imha revealed a dominant index of 0.57 (±0.18), a diversity index of 2.87 (±0.31), an evenness index of 0.73 (±0.04), and a richness index of 4.17 (±0.71). The results of functional feeding group analysis showed that a high proportion of species and individuals are gathering collectors. The results of functional habitat group analysis showed that a high proportion of species and individuals are clingers. The result of a physico-chemical water assay and dissolved oxygen and electric conductivity tests revealed that these measures increased when the water temperature decreased. The result of Pearson’s correlation analysis by biological factors and physico-chemical factors showed that species and electric conductivity are highly correlated with one another. Major inflow streams of Lake Andong and Lake Imha were exposed to various point pollution sources and non-point pollution sources. This implies a necessity for continuous monitoring of the aquatic ecosystems in order to effect systematic water quality management of Lake Andong and Lake Imha.

최근 셰일가스 산업의 호황과 더불어 셰일가스전에서 배출되는 폐수처리가 중요한 환경문제로 부각되고 있다. 셰일가스전 폐수는 총 용존고형물의 농도가 10에서 200g/L로 높기 때문에 역삼투 담수공정을 적용하기에 어려움이 있다. 본 연구에서는 셰일가스전 폐수를 처리하기 위해 저압에서 운전 가능한 정삼투 공정(FO)의 적용 가능성을 연구하였다. 특히 대표적으로 널리 활용되고 있는 유도용액인 NaCl과 NH3-CO2를 사용하여 셰일가스전 폐수에 포함되어 있는 2가 양이온이 FO공정에 미치는 영향을 알아보았다. FO공정 유도용액의 역확산은 막의 플럭스와 스케일로 인한 막오염에 중요한 영향을 끼치는 것으로 나타났다. 이를 통해 FO공정의 폐수 성상에 따라 유도용액 종류 선택 및 공정 디자인의 중요성이 입증되었다.

The effect of PEMFC trapezoidal channel wall contact angle on water removal characteristics is investigated with the volume of fluid (VOF) method. Two different contact angles 60 and 90 degrees are selected. In the case of the side and top wall contact angle of 60 degrees, stable semi-spherical droplets move along the top wall slowly. In contrast, complex shaped droplets move along the lower edge in the case of 90 degrees. Moreover, it is shown that very complex interaction patterns between different droplets which introduced into the channel at different times.

국제적 교역의 증가 및 기후 변화로 인해서 외래식물병해충의 유입이 해마다 증가하고 있다. 1990년대부터 자유무역협정(Free Trade Agreement) 대상국이 51개국까지 확대되면서 교역량과 대상 품목이 급격하게 늘어났다. 특히 배화상병과 같은 위험성이 높은 병은 우리나라의 과일 수출에 타격을 입히고 미국선녀벌레와 같은 해충은 과수원은 물론 도시조경과 산림수목을 가리지 않고 피해를 주고 있어 이들의 방제에 국가 재정지출 등의 사회경제적 비용을 지불하고 있다. 이들에 대해서 선제적인 대응방안을 마련하기 위해서 1900년대 이후 유입된 외래식물병해충의 분석을 실시하였다. 외래식물병해충은 총 87종이며 병이 40종 (진균 12종, 세균 12종, 바이러스 16종), 해충이 47종(매미 목 17종, 딱정벌레목 11종, 총채벌레목 5종, 나비목 5종, 파리목 3종, 벌목 3종, 선충 2종, 응애 1종)에 이른다. 유입경로가 밝혀진 76종은 병해충 중 묘목을 통한 유입이 40건으로 가장 많았고, 병은 종자(10건), 종서(6건), 매개충(4건) 순으로 해충은 화물(4건), 선박(3건) 순으로 유입이 많이 되는 것으로 확인되었다. 유입 병해충별 발견당시 병의 경우 33%, 해충의 경우 46%가 이미 전국에 분포하였으며, 이는 조기 발견율이 매우 낮음을 암시한다. 이러한 병해충 유입의 증가세로 인해 검역본부에서는 2010년부터 역학조사를 실시하여 5년간 32종에 대한 역학조사를 진행하였다. 또한 외래병해충 87종 중 41종(병 14종, 해충 27종)만이 검역대상으로 지정되어 있어 검역이 이뤄지고 있지 않은 대상이 많아 그들에 대한 상황분석과 개선이 요구된다.

금(Au)나노물질은 광학 및 바이오 분야에서 다양하게 응용될 수 있을 뿐만 아니라 식품 농작물 재배에 무기비료제 로 사용 시 기능성 및 품질 향상에 긍정적인 영향을 줄 수 있는 것으로 알려지면서 금 나노입자를 이용한 건강기능식 품 또는 기능성 농작물 재배에 대한 연구개발이 진행되고 있다. 따라서 식품 농작물 잔류와 체내 흡수 가능성에 따른 식품 및 생체 내에서의 정확하고 정밀한 분석법 확립과 안전성검증이 요구된다. 본 연구에서는 유도결합플라즈마 질 량분석기(ICP-MS)를 이용한 금 나노입자의 정량 분석을 확립하고자 전처리 방법을 최적화하고, 회수율, 정확성 및 정 밀성을 분석하여Au의 분석법을 확립하였다. 확립된 Au 정량 분석법을 이용하여 생체시료 내에서 금 나노입자의 정량 분석을 수행하여 생체 매트릭스의 영향을 확인하였다. 이러한 분석법을 바탕으로 장내 micro fold (M) 세포를 모사한 follicle associated epithelium (FAE) 모델과 일반 장관 상피세포 조건을 모사한 Caco-2 monolayer 모델을 이용하여 금 나노입자의 유입량을 비교 연구하였다. 그 결과, 생체 매트릭스 존재에 따른 금 나노입자 정량분석에 미치는 영향은 없는 것으로 나타났으며, 금 나노입자는 장관 상피세포 내 M 세포에 의해 에너지 의존적 endocytosis 기작에 의해 체 내 유입될 수 있는 것으로 확인되었다. 이러한 식품 농작물 무기비료로서 금 나노입자의 식품 및 체내 분석법 확립연 구 및 체내 흡수기작 규명은 추후 안전성 평가에 기초자료로 활용될 수 있을 것이다.

아산만의 해양수질의 계절적인 변화를 이해하기 위하여 2011년 12월부터 2013년 2월까지 4계절 동안 수질을 관찰하고, 담수유입으로 인한 해양수질 변화 관계를 통계적인 기법으로 분석하였다. 아산만의 해양수질 자료에 대한 요인분석 결과는 해양수질 변화를 주도하는 가장 중요한 요인은 담수유입(37.7 %)이며, 그 다음으로는 외해수의 영향(24.4 %)으로 나타났다. 아산만에서 담수의 주요 공급원은 만의 가장 안쪽에 위치한 아산호와 삽교호이며, 이들의 방류로 인해 아산만의 전체적인 수질의 공간 분포가 결정되는 것으로 보인다. 반면 담수 방류가 적은 겨울철에는 저층 재부유에 기인한 영향이 상대적으로 중요해진다. 전체적으로 담수 방류량의 계절적인 변화가 아산만 전체의 환경변화를 주도하고 있으며, 이로 인하여 DIP가 식물플랑크톤의 성장을 제한하는 요소로 나타났다.