According to the team at KAUST, this photodegradation process is known to be feasible but limited by the long treatment times it required. Luca Fortunato, Thomas Anthopoulos and colleagues have demonstrated that this photodegradation treatment can be accelerated with high-intensity light pulses generated from a xenon flash lamp.
“An interesting aspect of this work is that we combined the expertise and technologies of two different fields,” said Fortunato. He added that the collaboration between two different research departments - KAUST's Solar Centre and Water Desalination and Reuse Centre - allowed the team to adopt a pulsed light system that was previously used to process semiconductor materials for transistors and solar cells.
Organic micropollutants (OMPs), which are known as emerging contaminants, include a long list of pharmaceuticals, hormones, compounds in personal care products and industrial chemical additives. They are released from multiple locations, are highly persistent in water and can have toxic effects on human health, even at very low concentrations.
“They are being continually released into waterways by wastewater treatment plants, with conventional treatment methods proving to have only limited effects in removing these contaminants,” Fortunato said in a statement.
The researchers found that the effectiveness of high-intensity pulsed light (HIPL) varied significantly depending on parameters including the number of pulses and the total energy dose delivered by the light. This allowed them to identify the most effective conditions for treating a test solution containing 11 significant OMPs, including drugs, hormones and industrial chemical contaminants.
They found that the HIPL treatment triggers decomposition of the OMPs with extraordinary degradation rates.
“Our innovative approach allows for efficient removal of OMPs from water within milliseconds, making it ideal for high-throughput water treatment applications,” said Anthopoulos.
The treatment has the potential to become a highly effective, straightforward and scalable solution to an increasing environmental problem.
The team is working to improve the system’s efficiency still further and increase its throughput. Their next step is to scale up the treatment setup.
“We hope to soon build a pilot-scale reactor to more realistically assess the efficiency of the treatment on wastewater effluent,” Fortunato said.
The team's findings are detailed in the Journal of Water Process Engineering