Solar-powered water robot removes algal blooms 1,760 times faster

KIST solar-powered water robot removes algal blooms 1,760 times faster
Seyoung Moon

A solar-powered autonomous water purification robot developed by the Korea Institute of Science and Technology (KIST) operates in a pond on the KIST campus. Provided by KIST
A solar-powered autonomous water purification robot developed by the Korea Institute of Science and Technology (KIST) operates in a pond on the KIST campus. Provided by KIST
A technology has been developed that can remove algal blooms in rivers and lakes that occur every summer up to 1,760 times faster than conventional methods. 

The Korea Institute of Science and Technology (KIST) announced on the 2nd that a research team led by Principal Researcher Oh Hyeong-seok at the Clean Energy Research Center, together with teams led by Principal Researcher Kim Nam-dong at the Advanced Materials and Conductors Research Center and Principal Researcher Cho Hye-seong at the Extreme Properties Materials Research Center, has developed a “self-powered autonomous water-surface robot for algal bloom control” that operates solely on sunlight to remove algal blooms. 

An algal bloom is a phenomenon in which cyanobacteria and green algae proliferate massively, turning the color of the water green. When algal blooms occur, they generate foul odors and reduce dissolved oxygen in the water, causing fish kills, and they also produce toxic substances that affect the safety of drinking water sources. 

Algal blooms are mainly controlled by workers using boats to directly spray hydrogen peroxide solutions. Because they must repeatedly traverse wide water bodies, this requires substantial cost and manpower. There is also a problem in that stabilizers added for long-term storage of the chemicals reduce the efficiency of algal bloom removal. 
The research team developed a single-atom catalyst in which cobalt atoms are individually dispersed on a carbon-based material. Using this catalyst, hydrogen peroxide can be synthesized using only oxygen from the air and water. Hydrogen peroxide produced with the team’s technology was found to remove algal blooms up to 1,760 times faster than commercial hydrogen peroxide. 
The team combined the developed catalytic system with solar panels and a floating platform to complete the autonomous water-surface robot for algal bloom control. The robot charges its batteries with solar power during the day and can autonomously navigate both day and night. Through trial runs conducted in a pond on the KIST campus, the researchers verified that the system can effectively remove algal blooms. 
The team’s technology can be used in environments such as reservoirs and dams where power infrastructure is limited. Because hydrogen peroxide can be produced on-site in the required amounts without transporting chemicals, it can reduce transportation costs and the risk of chemical leakage. 

The researchers plan to scale up the system and gradually expand its applications to various water quality management settings, including rivers and large drinking water sources.