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.

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.