Carbon dots (CDs) were synthesized from phloroglucinol (PG) by simple heat treatment at 220–230 °C in the atmosphere without catalysts and solvents. PG-CDs heated at 220–230 °C could be completely dissolved in environmentally friendly water and exhibited a photoluminescence (PL) peak at 485 nm with 85 nm of the full width at half maximum (FWHM). The water-soluble polymer-dot-like PG-CDs were estimated to be 1.6–3.2 nm in size, and exhibited a wide range of PL wavelength at 370–630 nm. Since the PG-CDs are water-soluble materials, PG-CDs could be homogeneously mixed with a polymer such as polyvinylpyrrolidone (PVP) in water as a solvent, and PG-CDs/PVP films were prepared. The films exhibited PL characteristics that convert ultraviolet light at 350 nm to visible light above 400 nm. Thus, using PG as the raw material which has widely been produced industrially, the water-soluble fluorescent PG-CDs/PVP films could be prepared at a low cost by environmentally friendly methods.

Owing to their simplicity and ease of synthesis, carbon nanotubes (CNTs) have captivated attention of researchers. Many engineering applications have investigated the new features of nanostructured carbon nanotubes, such as large surface area, stiffness and durability. CNTs have opened up new opportunities for environmental improvement, pollution management and application in a variety of fields. Multiple types of pollution are produced as a result of population growth, urbanization and industrialization. CNTs are used to solve a variety of challenges, including environmental difficulties, water pollution, biomedical applications, and so on. It becomes an unavoidable present and future material. Different applications of CNTs have been presented in this review paper. CNTs are potential material having number of uses, including water purification, drug delivery, preservatives, catalysis, genetic engineering and artificial implants which are reviewed in this review article. This paper is presenting an explicit and systematic progress of CNTs for water treatment, medicinal uses drug delivery, artificial implants and so on, and a multitude of CNT applications in broad disciplines and their purification methods have been covered. The issues related to synthesis technologies, purification technology, bio-medicinal application and catalytic property of CNTs within the framework of different engineering applications and environmental impact are discussed in this study.

일본 정부는 2021년 4월 13일 일방적으로 후쿠시마 원전 오염수를 해양에 방 류하기로 결정했다. 일본의 원전 오염수 해양 방류는 후쿠시마 주변 해역 및 연안의 해양환경에 미치는 방사능 오염뿐만 아니라 우리나라 연안과 태평양 전 역으로 방사능이 유입되어 피해가 발생할 수 있으며, 해양 생태계 변화 등의 심각한 문제도 발생할 것이다. 일본의 원전 오염수 방류 결정에 대한 다양한 대응 방안이 검토되고 있으며, 유엔해양법협약을 중심으로 국제해양법재판소 제소 및 심각한 피해의 가능성과 상황의 긴급성이 있는 경우 잠정조치 신청도 할 수 있다. 이 논문에서는 일본의 원전 오염수 방류 결정에 대한 문제점을 살펴보고, 해 양환경 오염으로 인한 국제환경분쟁의 의의와 주요 특성에 관한 내용을 검토하 고, 소송에 대비하여 유엔해양법협약 관련 규정 및 판례들을 검토하여 시사점 을 도출하였다. 일본의 후쿠시마 원전 오염수 방류가 임박한 시점에서 문제 해 결을 위하여 최우선으로 유엔해양법협약을 근거하여 ITLOS 제소 및 잠정조치 신청을 하는 사법적 해결방안을 모색하고 동시에 한일 양국 간 또는 국제사회 의 공동 협력체계를 통한 외교적(비사법적) 해결방안 등 실효적인 해결방안을 제시하고자 한다.

This study aims to explore the appropriate water pressure control of water supply pipeline to reduce water losses of water supply network in Jinan-gun. The current water pressure status of each 5 blocks and the impact of optimized water pressure on improving revenue water rate were investigated. In order to obtain the flow rate and water pressure data of each small block, a smart hub is set in the pressure reducing valve chamber at the inlet of the small block, and a smart water pressure meter is installed in the fire hydrant and the faucet of the customer. For the pressure reducing valves installed for water pressure management system of each block, the diameter calculation standard and type of the pressure reducing valve are determined, and the application reasons are put forward. The analysis results of water pressure management for each small block in Jinan-gun show that the pressure control equipment and water pressure management need to be improved in four small blocks. The water flow rate in Jinan-eup and Sangjeon-myeon increases from 57.2% to 87.6% when the water pressure control is completed.

Sustainable and healthy diet is a challenge in recent world. Despite the global depletion of water resources, Korea has no system for controlling its water footprint. This study established the water footprint tables of Korean food using the Water Footprint Network databases, and applied them into two meal plans for 19~64 year-old adults recommended in the Dietary Reference Intakes for Koreans 2020. Nut, oil, and meat’s water footprints were higher and those of fruit and vegetable were lower. Sesame oil had the highest water footprint of 21,793 L/kg and pineapple had the lowest domestic water footprint of 102 L/kg. Water footprint of one serving size of beef was 925 L, that of chicken was 260 L, and those of soybean were 43 L in global and 81 L in domestic. The water footprint of the recommended 2,400 kcal meal plan was 2,882 L, and that of 1,900 kcal meal plan was 1,915 L. The water resources can be saved by choosing food with lower water footprint. The results of this study can be used in the further researches for more sustainable and healthier Korean diet.

급격한 산업화와 도시화로 인해 해양 오염이 심각해지고 있으며, 이러한 해양 오염을 실효적으로 관리하기 위해 수질평가 지수(Water Quality Index, WQI)를 마련하여 활용하고 있다. 하지만 수질평가지수는 다소 복잡한 계산과정으로 인한 정보의 손실, 기준값 변동, 실무자의 계산오류, 통계적 오류 등의 불확실성(uncertainty)을 내포하고 있다. 이에 따라 국내ㆍ외에서 인공지능 기법을 활용하여 수질평가지수를 예측하기 위한 연구가 활발히 이루어지고 있다. 본 연구에서는 해양환경측정망 자료(2000 ~ 2020년)를 활용하여 우리나 라 전 해역 즉, 5개의 생태구에 대한 WQI를 추정할 수 있는 가장 적합한 인공지능기법을 도출하기 위해 총 6가지의 기법(RF, XGBoost, KNN, Ext, SVM, LR)을 실험하였다. 그 결과, Random Forest 기법이 다른 기법에 비해 가장 우수한 성능을 보였다. Random Forest 기법의 WQI 점수 예측값과 실제값의 잔차 분석 결과, 모든 생태구에서 시간적 및 공간적 예측 성능이 우수한 것으로 나타났다. 이를 통해 본 연구에서 개발한 Random Forest 기법은 높은 정확도를 바탕으로 우리나라 전해역에 대한 WQI를 예측 가능할 것으로 사료된다.

This study was conducted to evaluate the filtration performance according to the feed temperature composed of NaCl and the operating pressure of the brackish water reverse osmosis (BWRO) process. The temperature is known that decides the filtration performance of reverse osmosis (RO). It is noted that temperature increase activates the permeate of salts due to augment of diffusivity and mass transfer. Filtration of the lab-scale RO system was performed with constant pressure and the constant flow was simulated. The salt rejection measured by the concentration of the feed and permeate was compared with water permeability and salt permeability in the conditions containing various temperatures (5, 10, 15, 20, 25, and 30℃) and pressures (10, 12, 15, and 18 bar). An increase in feed temperature from 5 °C to 30 °C caused a 4.65% decrease in salt rejection in CSM, due to an increase in salt permeability (4.06 times) rather than an increase in water permeability (2.62 times). Specific energy consumption (SEC) was calculated by using an electricity meter set in the RO system. It was expected that the SEC by the increases in temperature and pressure decreased due to the viscosity decline of the feed and the permeate flux augment, respectively. The SEC decreased by 63.4% in CSM and by 54.3% in Nittodenko when the feed temperature increased from 5 °C to 30 °C. It discussed how to operate the optimal RO process through the effect of temperature and operating pressure and the comparison of SEC.

동해연안의 반폐쇄성 해역인 영일만에서 고주파해양레이더(HF-Radar)로 측정된 표층 해수유동 자료를 활용하여 1)바람과 수평 적인 해수유동 사이의 상관성을 파악하고 2)수직적으로 조밀한 간격의 층별 수온시계열 자료와 연계하여 수평적 및 수직적 해수유동의 특성을 파악하였다. 시계열 관측기간 중 영일만 해역의 전역에 걸쳐 북동풍이 우세하게 나타났을 때 표층부터 저층까지 수온의 급격한 상승이 동반되었다. 또한 표층의 장주기 해수유동에서도 풍향과 유사한 방향의 흐름이 뚜렷하게 관측되었다. 바람과 표층 해류 사이의 지 연상관 분석을 통해 영일만에 북동풍의 바람이 불기 시작하여 일정하게 지속된다면 짧은 시간(1 ~ 2시간) 내에 남서향의 표층 해류가 발 생되는 것을 확인하였다. 일평균된 장주기 표층 해류로부터 수렴과 발산을 계산하였고 이를 통해 층별 관측지점에서 발생한 두 번의 급 격한 저층수온 상승이벤트가 모두 영일만의 북동풍과 연관된 표층 해수(상대적 고온수)의 수렴(침강) 현상으로 인해 나타난 것으로 판단 하였다.

To improve the safety of tap water, a study was conducted on the introduction of sanitation safety certification system for water treatment plants(WTPs). In order to produce and supply safe tap, the inflow of pollutants should be blocked as much as possible during the tap water production process, and contaminated materials should be removed or inactivated to a safe level in the WTPs. In order to block the inflow of pollutants in WTPs, it is necessary to strengthen the sanitation management such as installation of facilities for preventing inflow and habitat of larvae, and to remove or inactivate pollutants in the tap water production process, strengthening the safety management such as enhanced turbidity management is needed. Sanitation and safety management in the WTPs can be significantly improved by introducing certification system of WTPs. This will induce continuous improvement in water purification plants with insufficient sanitation and safety management, and provide incentives for WTPs with good sanitation and safety management. In addition, when the WTPs sanitation and safety certification system is established, it is desirable to expand the proposed system from WTPs to the entire process of tap water production and supply.

Undenatured castor oil and trimethylolpropane (TMP) were used to obtain bio-based water-based polyurethane. Isophorone diisocyanate (IPDI) was incorporated into the formulation to obtain a transparent film, and ethylenediamine (EDA) was used for chain extension. In order to measure the change in physical properties according to the contents of castor oil and TMP, each tensile strength, elongation, and abrasion resistance test was conducted. As the contents of castor oil and TMP increased, the tensile strength increased, the elongation decreased, and the surface hardened strongly as the respective contents increased.

The “Carbon Neutral” has become the most important goal to achieve in the era of the climate change crisis. K-water has prepared a roadmap for implementing “Carbon Neutral” by 2050. However, only the reduction targets and strategies for scope 1 and 2 have been set, so the management of carbon generated during the construction project and upfront carbon is not being implemented. Therefore, in this study, the criteria and methodology for estimation carbon emissions in the construction sector at domestic and foreign were reviewed, and a methodology for estimation carbon emissions suitable for K-water construction projects was presented, and a case study was conducted. As a result, most of the carbon emissions were more than 90% of the upfront emissions due to material production. Therefore, upfront carbon management is required for carbon management of K-water construction projects, and it is necessary to quantify carbon emissions through GHG construction inventory, etc., and to establish strategies for future reduction technologies.

국내 Y정수처리시설에 20-40 m3/m2/h의 표면부하율을 갖는 고속 용존공기부상공정을 도입하였다. 우선, 용존공기부상공정과 입상활성탄 공정이 결합된 반응기를 일처리용량 500 m3/day의 조건으로 운전하였다. 운전결과는 두 공정이 원수내 탁도, 조류, 지오스민, 2-MIB를 감소시킬 수 있음을 증명하였다. 도출된 최적 설계요소를 활용하여 현장규모의 공정(5,000 m3/day)에 용존공기부상공정을 도입하였다. 여름철 56일간 조류와 탁도 제거율을 평가하였다. 처리수 내 조류의 개체수는 20-30 cells/mL 이하로 유지되었으며, 조류 제거효율은 80-89%를 기록하였다. 침전법 및 용존공기부상공정 처리수질의 탁도 제거효율을 비교한 결과 평균 탁도 제거효율은 77%를 나타냈다. 이러한 결과들은 고속 용존공기부상공정이 여름철 음용수의 탁도 및 조류와 같은 저밀도 고형물을 제거하는데 유의미한 방법임을 나타냈으며, GAC는 맛･냄새를 유발하는 화합물(지오스민, 2-MIB)를 제거할 수 있는 공정 옵션인 것을 확인하였다.

본 연구는 장미 ‘Bubble Gum’의 절화수명을 연장시키기 위하여 미산성 차아염소산수(Slightly acidic hypochlorous water, HOCl, pH 6.26)의 처리효과와 절화수명 연장제로써 의 가능성을 구명하고자 수행되었다. 침지처리는 30μL･L-1의 미산성 차아염소산수를 0분, 0.5분, 1분, 3분, 5분간 침지처 리 후 수돗물(Tap water, control)에 꽂아 두었다. 대조구의 절화수명은 8.7일인데 비해 5분 침치처리 시 10.8일로 대조 구보다 2.1일 수명을 연장시켰다. 상대생체중은 모든 처리구 에서 2일까지 증가하였고, 수분흡수율은 모든 처리구에서 6일 까지 증가하다가 감소하는 추세를 보였다. 화색 변화율인 ΔE 값은 3분(5.25), 5분(6.48), 30초(6.65), 1분(6.79) 침지처리 에서 대조구보다 낮았으며, 상대 화폭 증가율은 5분 침지 처 리구가 145%로 화폭의 증가율이 가장 컸고, 엽록소함량은 처 리 간 차이가 없었다. 결론적으로 절화장미 ‘Bubble Gum’의 절화수명은 미산성 차아염소산수의 5분 침지 처리가 효과적 으로 연장시켰다.

Wild birds, especially aquatic birds, are the natural reservoir of avian influenza virus (AIV), and many kinds of water body can be contaminated with feces of these birds. Seasonally, AIVs can be dissolved in the environmental water from the feces of the infected birds, and this water can be a target for viral detection and identification. In this study, we employed and tested three different filters for concentrating AIV, and it was shown that high concentration factor in terms of viral density could be achieved with viral samples diluted with natural water. Wild bird fecal samples containing low pathogenicity H5 AIVs were successfully concentrated with the adsorption and elution method using mixed cellulose esters membrane; the recovery rate of virus was 35.5 % and the concentration factor was about 50 on average. For the larger volume of water sample, we proved that an inline disposable filter with high surface area, 300 cm2, has a comparable concentration factor to the adsorption and elution method and the filter could be used in the field conveniently by being plugged into peristaltic pump. These validated methods for water sampling may be used as a supplementary for virological surveillance on wild migratory birds or during the epidemiological investigation on the environment near affected premises by AIV.

In general, fire accidents in tunnels are sufficiently preventable, but the damage is very large. Therefore, the number of highway traffic accidents is high in spring when spring fatigue occurs and the traffic volume for maple travel increases. In particular, when analyzing the cause of death of people killed in fire accidents in tunnels, it is analyzed that most of them are suffocated by smoke. Therefore, in this study, it can be said that it is meaningful to make a social contribution to reduce the number of traffic accident deaths by establishing an efficient fire suppression system for fire accidents in tunnels.

Maritime navigation is an important mode of transportation in the country. With the development of the country and the world, there will inevitably be higher requirements for the safe transportation of ships in the future. Therefore, intelligent ships have become the latest research direction in ship design. And with the gradual development and improvement of big data and artificial intelligence technology in the industrial field, smart ships are an inevitable trend in the development of the shipbuilding industry. Smart ships need to maintain the stability of the ship to ensure the safety of the ship when operating at sea. Therefore, the research on the autonomous stowage of ballast water for smart ships in the future is very important. This paper analyzes the development background of intelligent ships, introduces the ship optimization model and optimization design algorithm, and speculates the future development direction of intelligent ships.