July 11, 2024
Australian and Chinese water scientists have proposed a more effective method to remove organic pesticides from drinking water, reducing the risk of contamination and potential health problems.
The 62% increase in global pesticide use over the past 20 years has heightened fears that many of these chemicals could end up in our waterways and cause cancer.
Powdered activated carbon (PAC) is currently used to remove organic pesticides from drinking water, but the process is expensive, time-consuming, and not 100% effective.
Water researcher at the University of South Australia Professor Jinming Duan collaborated with his former doctoral student, Dr. Wei Li of Xi’an University of Architecture and Technology and Chinese colleagues in a series of experiments aimed at improving the process.
The researchers found that by reducing PAC particles from the current commercial size of 38 μm (one millionth of a meter) to 6 μm, up to 75% less powder was needed to remove six common pesticides, achieving significant water treatment savings.
At 6 μm, the PAC particles are still large enough to be filtered out after the adsorption process, ensuring that they do not end up in drinking water after the toxic pesticides are removed.
According to Professor Duan, pollutants in our waterways are expected to increase in the coming decades as the world’s population and industrial development increase.
“It is therefore essential that we develop cost-effective treatment processes to ensure the safety of our waterways,” he says.
Their results have been published in the journal Chemosphere.
“Pesticides cannot be removed by conventional water treatment processes such as flocculation, sedimentation and filtration. Powdered activated carbon does the job, but existing methods have limitations. Our study has identified how we can make this process more efficient.”
About 3.54 million tonnes of pesticides were applied to agricultural crops worldwide in 2021, according to the Statista Research Department.
It is worrying that despite efforts to increase their effectiveness, it is estimated that only 10% of pesticides reach their targets, with most chemicals remaining on the surface of plants or entering the environment, including soil, waterways and the atmosphere.
Toxicological studies have suggested that long-term exposure to low levels of pesticides – mainly through food or drinking water – may increase the risk of cancer and other diseases.
“That’s why it’s important to reduce their levels as low as possible,” says Professor Duan.
The researchers also hope to study how ultrafine activated carbon could be used to remove toxic polyfluoroalkyl substances (PFAS) and perfluorinated compounds (PFCs) found in many consumer products, which have been linked to adverse health effects.
“Efficiency and feasibility of ball-milled powdered activated carbon (BPAC) for the removal of organic pesticides in conventional drinking water treatment process” is published in Chemosphere.
DO I: 10.1016/j.chemosphere.2024.142229
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Contact for maintenance: Professor Jinming Duan E: jinming.duan@unisa.edu.au
Media contact: Candy Gibson M: +61 467 255 684 E: candy.gibson@unisa.edu.au