• 물과 미래
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• 제29권2호
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• pp.167-178
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• 1996

하천 및 호소수 수질의 온라인 계측을 위한 수질자동측정망의 설계에서 측정위치와 항목의 선정은 전체시스템의 성능을 결정짓는 중요한 인자이다. 본 논문에서는 상수원유역의 상시수질감시 및 사전경보 기능을 갖는 측정망의 구축이 측정위치와 항목을 결정하는 방법을 연구하였다. 측정위치를 결정하기 위한 선정기준은 상수취수량과 고정오염원의 위치를 바탕으로 대상지역에 대한 거시적 후보지점을 선정한 뒤, 구체적인 지점은 오염물질 유하거리를 기준으로 단계적으로 결정한다. 측정항목은 유역의 오염특성과 수질오염사고 이력을 참고하되, 경제적인 측면을 고려하여 필수측정항목과 선택항목으로 나누어 위치별로 달리하는 방안을 제시하였다. 제안방법을 낙동강유역에 적용함으로써 측정망 구성과정을 예시하였다.

• 한국물환경학회지
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• 제26권6호
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• pp.994-999
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• 2010

The toxin of Cyanobacteria (blue-green algae) during summer season has been a problem and early prevention should be considered. A variety of methods can be used to forecast algal blooms and this study aims at examining feasibility of chlorophyll-a. The real-time data were collected by automatic water quality monitoring system (AWQMS) in Daecheong reservoir and invalid data were sorted by experts. And then, the sorted data were filled using linear interpolation. When the concentration of chlorophyll-a increased by $15mg/m^3$, water temperature and pH exceeded $26.8^{\circ}C$ and 9.5 respectively. As a result of correlation between chlorophyll-a and other parameters(i.e. water quality items and hydrological data), temperature (r=0.502 - 0.574), pH (r=0.583 - 0.681), total organic carbon (TOC, r=0.583 - 0.681) comparably had higher values. Meanwhile, the data around a day or two showed the highest correlation. In addition, chlorophyll-a is considered to be significantly effected by precipitation and inflow.

• 한국전자통신학회논문지
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• 제16권5호
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• pp.957-968
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• 2021

육상 양식장 수질 모니터링 시스템의 데이터 신뢰도 향상 및 효율적 시스템 운영을 위하여 현재 시험 운영중인 육상 해수 양식장과 해양환경정보망(완도조위관측소)의 수질 데이터를 비교 분석한다. 또한 수질 모니터링 시스템의 데이터 오류를 제거하고, 측정 데이터의 신뢰도를 높이는 방법으로 데이터 유효성 검증, 데이터 범위 필터, 데이터 변위 검사를 적용하여 비교 분석한다.

• 상하수도학회지
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• 제20권4호
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• pp.573-584
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• 2006

This study was carried out to investigate the causes of fish kills in the Yudeung Stream in Daejeon, Korea using literature reviews, governmental and our water quality monitoring data of the study site, rainfall data, intensive water quality monitoring during rainfall events, sediment pollutant contents and laboratory bioassay tests. Fish kill in urban streams can be caused by combined effect of reduction in dissolved oxygen concentration, increase in toxic material or increase in turbidity in waterbody due to introduction of surface runoff or effluent of combined sewer overflows after rainfall from the watershed areas. Despite of extensive and intensive field surveys and laboratory tests, it was found that those conventional methods have limitations to identify causes of fish kills in urban streams. It would be necessary to use dynamic water quality modeling to predetermine the range and level of water pollution in the stream and automatic water quality monitoring system that can collect water samples and detect water quality continuously.

• Journal of Biosystems Engineering
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• 제42권4호
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• pp.350-357
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• 2017

Purpose: In-situ monitoring of water quality is fundamental to most environmental applications. The high cost and long delays of conventional laboratory methods used to determine water quality, including on-site sampling and chemical analysis, have limited their use in efficiently managing water sources while preventing environmental pollution. The objective of this study was to develop an on-site water monitoring system consisting mainly of an Arduino board and a sensor array of multiple ion selective electrodes (ISEs) to measure the concentration of $NO_3$ ions. Methods: The developed system includes a combination of three ISEs, double-junction reference electrode, solution container, sampling system consisting of three pumps and solenoid valves, signal processing circuit, and an Arduino board for data acquisition and system control. Prior to each sample measurement, a two-point normalization method was applied for a sensitivity adjustment followed by an offset adjustment to minimize the potential drift that could occur during continuous measurement and standardize the response of multiple electrodes. To investigate its utility in on-site nitrate monitoring, the prototype was tested in a facility where drinking water was collected from a water supply source. Results: Differences in the electric potentials of the $NO_3$ ISEs between 10 and $100mg{\cdot}L^{-1}$ $NO_3$ concentration levels were nearly constant with negative sensitivities of 58 to 62 mV during the period of sample measurement, which is representative of a stable electrode response. The $NO_3$ concentrations determined by the ISEs were almost comparable to those obtained with standard instruments within 15% relative errors. Conclusions: The use of the developed on-site nitrate monitoring system based on automatic sampling and two-point normalization was feasible for detecting abrupt changes in nitrate concentration at various water supply sites, showing a maximum difference of $4.2mg{\cdot}L^{-1}$ from an actual concentration of $14mg{\cdot}L^{-1}$.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제18권1호
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• pp.46-63
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• 2024

One of the biggest dangers in the globe is water contamination. Water is a necessity for human survival. In most cities, the digging of borewells is restricted. In some cities, the borewell is allowed for only drinking water. Hence, the scarcity of drinking water is a vital issue for industries and villas. Most of the water sources in and around the cities are also polluted, and it will cause significant health issues. Real-time quality observation is necessary to guarantee a secure supply of drinking water. We offer a model of a low-cost system of monitoring real-time water quality using IoT to address this issue. The potential for supporting the real world has expanded with the introduction of IoT and other sensors. Multiple sensors make up the suggested system, which is utilized to identify the physical and chemical features of the water. Various sensors can measure the parameters such as temperature, pH, and turbidity. The core controller can process the values measured by sensors. An Arduino model is implemented in the core controller. The sensor data is forwarded to the cloud database using a WI-FI setup. The observed data will be transferred and stored in a cloud-based database for further processing. It wasn't easy to analyze the water quality every time. Hence, an Optimized Neural Network-based automation system identifies water quality from remote locations. The performance of the feed-forward neural network classifier is further enhanced with a hybrid GA- PSO algorithm. The optimized neural network outperforms water quality prediction applications and yields 91% accuracy. The accuracy of the developed model is increased by 20% because of optimizing network parameters compared to the traditional feed-forward neural network. Significant improvement in precision and recall is also evidenced in the proposed work.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 2017년도 춘계공동학술대회
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• pp.122-122
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• 2017

Recently, environmental problems have become an area of growing interests. In-situ monitoring of water quality is fundamental to most environmental applications. The accurate measurement of nitrate concentrations is fundamental to understanding biogeochemistry in aquatic ecosystems. Several studies have reported that one of the most feasible methods to measure nitrate concentration is the use of Ion Selective-electrodes (ISEs). The ISE application to water monitoring has several advantages, such as direct measurement methodology, high sensitivity, wide measurement range, low cost, and portability. However, the ISE methods may yield inconsistent results where there was a difference in temperature between the calibration and measurement solutions, which is associated with the temperature dependence of ionic activity coefficients in solution. In this study, to investigate the potential of using the combination of a temperature sensor and nitrate ISEs for minimizing the effect of temperature on real-time nitrate sensing in natural water, a prototype of on-site water monitoring system was built, mainly consisting of a sensor chamber, an array of 3 ISEs, an waterproof temperature sensor, an automatic sampling system, and an arduino MCU board. The analog signals of ISEs were obtained using the second-order Sallen-key filter for performing voltage following, differential amplification, and low pass filtering. The performance test of the developed water nitrate sensing system was conducted in a monitoring station of drinking water located in Jeongseon, Kangwon. A temperature compensation method based on two-point normalization was proposed, which incorporated the determination of temperature coefficient values using regression equations relating solution temperature and electrode signal determined in our previous studies.

• 제어로봇시스템학회논문지
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• 제14권1호
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• pp.36-41
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• 2008

Cooling tower is an important equipment of the cooling systems for large buildings like factory and department store. Water used for cooling in cooling tower is reused continuously. If the water is polluted, corrosion and scale can happen at equipments and pipes. In order to prevent this problem, it is necessary to control the water quality using chemicals. To control the water quality, an automatic control system is designed, fabricated, and experimented. The control system is based on an imbedded microcontroller. Relays are used for power driving, an LCD and LED for display, and RS485 for remote data acquisition. Monitoring program is also developed for easy man-machine interface and extraction of data stored in the imbedded processor and EEPROM. The control system calculates amounts of chemicals necessary using sensor data and injects the chemicals into the cooling tower on proper time. The developed water quality control system is expected to reduce cost of maintenance and extend the lifetime of the cooling systems with low cost.

• 대한환경공학회지
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• 제34권12호
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• pp.863-870
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• 2012

본 연구에서는 디지털 수도계량기(smart water meter) 연계형 상수도 원격검침시스템(automatic meter reading)의 국외 시장동향 및 원격검침시스템의 각 구성 요소기술의 개발현황과 현장적용 사례 등을 조사 분석하였다. 국외의 디지털 수도계량기 제조업체는 주로 미국 또는 유럽업체들로서 최근에는 북미뿐만 아니라 아시아 및 유럽에서도 원격검침시스템 사업을 확장하고 있다. 대부분의 디지털 수도계량기 제조업체는 원격검침용 디지털 수도 계량기에서 측정된 데이터를 활용하여 실시간 소비량 검침 및 비용 고지, 절수, 누수탐지, 수질 모니터링, 유량제어 등의 기능이 부가된 통합관리시스템(integrated water management system)과 연계하여 운영하고 있다. 데이터 전송방식은 디지털 수도계량기, 센서를 통해 검출된 데이터를 근거리 통신망(neighborhood area network)을 통해 수집기(data concentration unit)로 전송 후 광역 통신망(wide area network)을 통해 검침서버로 전송하였으며, 데이터 전송방식은 도시 규모, 계량기의 밀도, 전력공급 여부 및 통신망의 설치 여부 등을 종합적으로 고려하여 결정되었다. 일반적인 검침방식은 (1) 고정망(fixed network)을 통한 중앙 검침, (2) 차량(drive by)을 이용한 검침, (3) 사람(walk by)에 의한 검침, 그리고 (4) 비행식(fly by) 검침방식 등이 적용되었다. 전 세계적으로 디지털 수도계량기 연계형 원격검침시스템이 확산되어 용수 및 에너지를 절감하고 수도 요금을 절약하여 온실가스의 배출을 최소화하고 있는 것으로 판단된다.

• 문화기술의 융합
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• 제10권2호
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• pp.525-530
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• 2024

환경정보를 실시간으로 획득하여 정보를 제공하는 환경 모니터링 시스템 필요성이 확대되고 있다. 특히 공공수역 수질관리의 경우 법적으로 수동측정과 자동측정을 통해 상시 관리를 진행해야 하며, 대기오염도 탄소중립 실현과 연관하여 미세먼지, 배기가스 저감을 위한 상시 측정 및 관리가 필요한 실정이다. 본 연구에서는 수질오염 및 대기오염 정보를 실시간으로 측정하여 모니터링을 할 수 있는 시스템을 구현하였다. 측정을 위한 도구로 육상과 수상을 동시에 이동 가능한 호버크래프트를 활용하였다. 호버크래프트 본체에 수질측정 및 대기오염측정 센서를 장착하고 그 정보를 실시간으로 모니터링 시스템으로 전송할 수 있는 통신 모듈을 장착하였다. 환경측정용 호버크래프트의 구조를 설계하였으며, 실시간 정보전달 통신 모듈로는 저전력 장거리 통신이 가능한 LoRa 모듈을 적용하였다. 실제 하드웨어 구현을 통해 제안한 시스템의 동작 성능을 확인하였다.