Low-Cost Water Quality Sensors for IoT: A Systematic Review

Abstract

In many countries, water quality monitoring is limited due to the high cost of logistics and professional equipment such as multiparametric probes. However, low-cost sensors integrated with the Internet of Things can enable real-time environmental monitoring networks, providing valuable water quality information to the public. To facilitate the widespread adoption of these sensors, it is crucial to identify which sensors can accurately measure key water quality parameters, their manufacturers, and their reliability in different environments. Although there is an increasing body of work utilizing low-cost water quality sensors, many questions remain unanswered. To address this issue, a systematic literature review was conducted to determine which low-cost sensors are being used for remote water quality monitoring. The results show that there are three primary vendors for the sensors used in the selected papers. Most sensors range in price from US$6.9 to US$169.00 but can cost up to US$500.00. While many papers suggest that low-cost sensors are suitable for water quality monitoring, few compare low-cost sensors to reference devices. Therefore, further research is necessary to determine the reliability and accuracy of low-cost sensors compared to professional devices.

From Radio to In-Pipe-Acoustic Communication for Smart Water Networks in Urban Environments: Design Challenges and Future Trends

“…It is intended to provide some details regarding the possible applications, the sensors exploited, and the characteristics of the wireless communication channel. More exhaustive reviews on such topics can be found in the literature [2,4,6,[28][29][30][31].…”

“…Measured information include but are not limited to pressure, temperature, flow, pH, turbidity. Such quantities can be used to assess water quality [6,7], detect and locate leaks [3,8] and monitor the health state of the structure in general [9,10]. Data transfer among the nodes of the Water Sensor Network (WSN) relies on radio-based communication in the vast majority of cases.…”

A low-cost spectroscopic nutrient management system for Microscale Smart Hydroponic system

“…The previous research demonstrates that EC probes possess certain qualities that make them suboptimal for MSHS deployment. Firstly, EC probes have a short life span and cannot be left in the solution indefinitely [ 24 , 28 ]. Separate measuring tanks [ 22 , 25 ] or pumping the solution through a pipe with mounted sensors [ 26 ] have been proposed but do not address the durability concerns of EC probes.…”

“…Silva, Löfkvist [ 35 ] proposed a system that pumps nutrient solution through a tube with a penetrative UV-Vis spectrometer (STS-UV-L-50-400, Ocean Insight ) set up. Using a self-learning AI model, the system was able to successfully observe changes in the N, phosphorus (P) and K. This system, using the self-learning AI model, was then used to test samples that were collected from different stages of growth from a greenhouse [ 24 ]. These samples were put through the system and their nutrient content was successfully analyzed showing that this technique could be used to manage a nutrient solution accurately.…”

“…The primary is cost. Silva, Löfkvist [ 35 ] and de Camargo, Spanhol [ 24 ] use spectrometers (Ocean Insight Inc.) that cost hundreds of dollars and are aimed at large scale greenhouse style deployment. Additionally, the system pumps nutrient through a measuring chamber, adding complexity to the system design.…”