Innovating water quality monitoring systems: Contactless measurement method

Today’s water quality monitoring system involves the deployment of water qualities sensors or probes. However, they are continuously exposed to harsh environments and biofouling. Choo Chun Keong, director and founder of NexusBit Integral, discusses more on contactless water quality sensor and how it removes the issues of water-related biofouling and complex installations., the contactless water quality monitoring sensor.

Monitoring the water qualities of water bodies like reservoirs and lakes is a critical process in water resources management and corrective actions. One of the key water quality indicators is the concentration of algae in the water system. Algae blooms put additional stress on water process plants, increase public health risk, endanger marine life and lead to further quality abnormalities issues. Algae related issues have become more frequent with rapid urbanisation and global warmer climate.

Today, the most common method for real-time monitoring of water quality and algae trends is using conventional in-water probes, which are constantly exposed to biofouling. These in-water probes require regular on-site maintenance to prevent measurement drifts and sensor degradation from biofouling.

Maintenance puts a strain on manpower resources; increased on-site manpower and expertise are needed with more monitoring locations. Site maintenance typically forms the more significant part of the total cost of ownership for real-time water quality monitoring systems and is the key limitation for large scale deployment. This is also the bottleneck for real-time water quality monitoring to better leverage recent advances in the Internet of Things (IoT) and big data technologies.

The new solution
NexusBit Integral has been working with PUB, Singapore’s national water agency to develop an alternative method to simplify real-time monitoring of the water quality. The company’s solution is a contactless measurement sensor that measures water quality parameters, including turbidity, chlorophyll-a and colour dissolved organic matters – absorption (CDOM) above the water surface without any physical contact in the water. Therefore, it removes any water-related biofouling and complex site installations.

Contactless measurement also unfolds new methods of sensor deployments that were previously not possible with conventional in-water sensors, which required careful considerations in both environmental factors like water current flow, corrosion, and safety consideration for sensor retrieval. Using a contactless measurement sensor, this can be achieved by simply mounting it on an existing land structure that has a direct view over the water bodies.

The full article is available on the latest edition of Water & Wastewater Asia Mar/Apr 2022 issue. To continue reading, click here.