Could used coffee grounds be repurposed to help clear up environmental toxins?
That’s the topic of new research published by the Journal of Chemical Technology and Biotechnology, which notes that coffee grounds could be re-utilised as an adsorbent of bentazone, a herbicide commonly used in agriculture.
‘Currently, the contamination of groundwater and surface water is one of the most pressing environmental problems – the biggest challenge of this century is to prevent water pollution,’ the authors state. ‘Waste effluents in rural areas are released en masse into rivers and lakes. Agricultural pesticides are known to cause adverse social and environmental impacts and induce resistance in target organisms. Herbicides are commonly used to control and combat weed resistance.
‘Bentazone is the most used herbicide in agriculture. The molecule is utilised to manage broad-leaved weeds such as beans, corn, and rice.’
The authors highlight recent studies indicating that bentazone poses significant neurotoxicity risks, impeding the proper functioning of the nervous system and posing harm to mammals. They add that the adverse effects of herbicides, including bentazone, in water pose a risk to human health, even at low concentrations.
Coffee consumption
Coffee is the second most traded product in the world, behind oil, the authors add, with high coffee consumption generating around 2.1 billion tonnes of spent coffee grounds each year.
In their study, researchers discovered that when they utilised zinc chloride to activate carbon derived from used coffee grounds, the resulting activated carbon exhibited a 70% efficiency in removing bentazone.
‘Biochar from spent coffee grounds has been used as a carbonaceous material to remove many contaminants, such as antibiotics, heavy metals, and dyes, owing to the rich surface functional groups and porous structure,’ the authors state.
Water pollutants
Additionally, the activated carbon proved to be effective in a high sensitivity test for water pollutants.
‘The efficiency of removing bentazone from the aqueous medium after adsorption also was proven by the eco-toxicity results obtained, validating the adsorbent used as highly efficient in removing the herbicide in question from the aqueous medium,’ as the authors put it.
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