Industries may soon have a green and cost-effective way of treating wastewater, thanks to a novel electrochemical water purification system developed by researchers from NUS Engineering.
The purification system, which removes 99 per cent of stubborn organic contaminants without leaving secondary waste, can help industries reuse the wastewater they generate or discharge it in a form that does not harm the environment.
The invention operates on low electrical power without the need for chemicals to be physically added. When electric current is passed through the wastewater, electrodes generate hydrogen peroxide and hydroxyl radical, powerful oxidising agents that continuously break down complex organic compounds present into water and carbon dioxide. It is capable of cleaning 10 litres of wastewater in six hours.
Many of today’s industries require large volumes of high quality water. The global demand for wastewater recycling and reuse reached nearly $16.4 billion (US$12.2 billion) in 2016 and is expected to exceed $29 billion (US$22 billion) by 2021.
The team’s novel water purification system could be employed in electronic and pharmaceutical industries where the wastewater generated contains high concentrations of solvents and complex organic substances that are non-biodegradable and harmful to human and environmental health. It could also benefit other industries such as mining, oil and gas, textile, shipping and agriculture. Factories could also control the purity of the water according to their needs, while reducing their reliance on third parties for wastewater processing or disposal.
“There is currently no gold standard for the treatment of wastewater that contains such stubborn organic compounds. In some cases, industries have to incinerate their wastewater which is very costly. Our system provides a solution for industries to produce clean water from wastewater in a more cost-effective manner,” explained Assistant Professor Olivier Lefebvre, who led the research team. He added that the system can be easily combined with solar power to make it even more sustainable.
The team has since filed two patents for the technology and is testing the system on more types of wastewater to further optimise its design and efficiency.