As our world progresses towards more urbanized living environments, basic needs such as clean water will become more difficult to provide. Our team seeks to develop a sensor capable of monitoring content levels of unwanted substances in waterways and reservoirs. While many solutions to this problem exist, our project is intended to be durable and self-sustaining, easy to install and operate, and able to be integrated into an Internet of Things (IoT) ecosystem.
While water has many factors that can be monitored, two main substances that can contaminate water are nitrogen and phosphorus. In high concentrations, they can contribute to algae growth which effectively pollutes water. Once algae growth has begun, it is a much harder problem to deal with. By monitoring changes in nitrogen and phosphorus concentrations, our project can predict and thus prevent algae growth providing a more sustainable water solution. Our concept consists of three parts: an innovative sensor solution, a semi-submersible platform, and an IoT network interface.
Sensor: Previous research has shown that nitrogen and phosphorus can be measured using NIR, or near infrared spectroscopy. Using a spectroscope allows accurate data to be collected without direct contact with water. This reduces the chance of erosion or decomposition of the sensor. The sensor emits light in the near-infrared, ultra-violet, and visible light spectrums and the corresponding reflections are recorded. By comparing the reflection data to values of a sample of clean water, the composition of the water can be determined.
Platform: The sensor will need to be placed near or in water while being enclosed in a waterproofed housing. A floating platform is a simple way of storing necessary electronics above water while allowing the sensor to be placed in the water. The platform can either be anchored, creating a static data point in a waterway or reservoir, or left untethered allowing for mobile data collection. As water flows through the floating platform, the sensor can monitor substance concentrations.
IoT Network: In order to efficiently monitor a source of water, multiple data points may be required. By employing a network of sensors connected to an IoT ecosystem, data can be collected and analyzed. Further, this data can be observed in real-time, giving a graphical representation of the quality of water over time. The sensors can even be programmed to warn the user when approaching high concentrations of nitrogen or phosphorus.
Preliminary research shows that we can use a mini spectroscopy sensor about 4 cm x 4 cm. A small, power efficient microcontroller such as the ESP-8266 in intended to be the processor for the device. This microcontroller also has built in Wi-Fi which is essential to integrating into an IoT network.
The floating enclosure only needs to house the electronics as well as provide a channel for water to flow through. The spectroscopy sensor would sit directly above the channel cutout allowing it to emit light signals directly into the water. An enclosure roughly 10 cm x 10 cm x 15 cm would be more than enough for our needs.
Battery duration is a major aspect of a device required to collect data over the course of one year. Water content does not drastically change over short periods of time. Thus, taking a reading twice a day would be sufficient in providing an accurate representation of the water condition. The ESP microcontroller can be left in low power “sleep mode” until it needs to take a reading and update the IoT network. With a relatively small battery, our device should have no problem functioning for extended periods of time. In addition, a small solar panel or water generator could be integrated to recharge portions of the battery, further extending the battery life of our device.
In addition to a physical prototype, we hope to also design a software package to connect the devices together and graphically display water composition in the form of a heatmap. This way, a user can quickly and efficiently determine the health of the water. The floating sensors can connect via Wi-Fi to a gateway that stores the data. Water condition is tracked over time and if a trend suggests high concentrations of nitrogen or phosphorus, it can wirelessly alert the user.
By installing our sensor solution in a reservoir or waterway, a user can easily monitor the health of the water and be warned of changes. In a reservoir, water composition is mostly consistent throughout meaning that fewer sensors can be placed with larger spaces in between. A waterway however will require more sensors as water content can change.
The device can either be anchored in place via a tether or held in place with guides. This way, the device can float on the surface of the water even if the water depth changes. If desired, the depth of the water can also be monitored and the data sent to the IoT network.
We are excited to be a part of this competition. If we are selected as finalists, we hope to develop a prototype capable of demonstrating accuracy and effectiveness in monitoring water.