Proposed End-Users

Our project contributes significantly to the overarching goal by addressing the critical issue of eutrophication in the Nakdong River and its impact on the local community. The first step to take in order to combat eutrophication is tracing the spots where nitrate and phosphorus flow into the river. This is an essential process because those are the primary substances that trigger the noxious algal bloom. With the advantages our biosensor possesses, we strongly believe our project will be a viable option for the local community to solve this issue, allowing for the prevention of eutrophication. The conventional nitrate sensors in the status quo are often unaffordable and ineffective to be employed in vast regions. Due to the turbulent aquatic environment (i.g. waves, organic compounds), the number of robust water-related sensors in the market is extremely small compared to other sensors. Even the existing sensors cost a high initial fee and persistent maintenance fee, which is practically unrealistic to install in large areas like the Nakdong River. Hence, Monitro employs synthetic biology, as it is an affordable choice that can be mass-produced.

Currently, there are over 1,500 chemical fertilizers — all rich in nitrate and phosphorus — piled near the Nakdong River, of which 40% are neglected and improperly stored. It is estimated that when the fertilizer flows into the river, the nitrogen and phosphorus concentration will multiply by up to 600 times, speeding up eutrophication. In fact, at Chilseo Point of the Nakdong River, the measurement for Blue-gree algae cells per mL reached a staggering 41,604 on June 22nd and 33,907 cells on a subsequent day. Note that an alert level is raised when there are 10,000 cells of algae measured per 1 ml on two or more occasions. To tackle this serious problem, we propose the following implementations.

Implementation into Real World

Water Sensors

It is also crucial to recognize our efforts to contribute to the biosensor industry, which remains significantly unexplored, with most of the public still unfamiliar with its concept. We aim to spread understanding of biosensors, making our involvement in the domain more meritorious. After successfully creating nitrate sensors, we imagine further developing BOD (Biological Oxygen Demand) measuring sensors of other chemicals, such as chlorine and phosphorus, by applying the construction used for nitrate sensors. By integrating these biosensors with the Arduino board, we expect to bring great innovation to the sensor market, providing an economical yet effective choice to measure underwater concentration.

Fig. 1. Various types of dissolved ions in bodies of water

Surveillance System

Furthermore, we also aim to establish an affordable surveillance system composed of nitrate biosensors that enable monitoring of nitrate levels in the Nakdong River. Since our product is highly economical, its customers can settle an extensive surveillance network by installing numerous sensors in different locations. Therefore, it will enable the local community to combat the issue proactively rather than relying on reactive measures, such as inspecting manually. Through the sensor, the local community will be able to acquire data about the spots where nitrates flow in, laying the essential groundwork for implementing artificial intelligence and databases to predict and prevent eutrophication in the future systematically.

Fig. 2. Surveillance System via Monitro

Smart Farm (aquaponics)

Fig. 3. “Aquaponics System: Definition and Benefits to Food Security.” Mulhern, Owen. Earth.Org, Accessed 12 October 2023.

Lastly, Monitro could also be employed in smart farming techniques, such as aquaponics, to effectively raise the yield of crops. Aquaponics is a form of agriculture that integrates the circulating fish tank into a hydroponics system, in which the plant grows without the soil. The water in the fish tank is enriched with nutrients thanks to the fish, and this water serves as the natural fertilizer for the crops. Monitro can play a significant role in featuring the concentration of nitrate present in the tank, allowing for the fine-tuning of the amount of nutrients provided to the plants. This optimization process, in return, is capable of increasing the crop yield.


  • 김민주, 박소은, and 김영기. "낙동강 수계 2021 년 남조류 발생현황." 한국공업화학회 연구논문 초록집 2021.1 (2021): 277-277.
  • 낙동강 녹조 원인 '야적퇴비' 장마 전 치우려했는데…27% 주인도 못찾아, 5 July 2023, Accessed 12 October 2023.
  • “낙동강 유역 퇴비 40% 부적정 보관...녹조 예방 위해 집중 단속.” 디지털타임스, 16 May 2023, Accessed 12 October 2023.
  • “장마 전 치우겠다더니…낙동강 야적퇴비 59% 그대로.” 연합뉴스, 5 July 2023, Accessed 12 October 2023.
  • 정동환, et al. "가축분뇨 관리및 퇴비· 액비 이용에 대한 개선방안 고찰." Journal of Environmental Impact Assessment 22.4 (2013): 345-359. Eom, Myung Chol-Kong, Dong Soo-Kwun, and Soon Kuk. "분뇨 처리형태에 따른 축산계 오염부하량 산정."