Analysis: new research has shown the potential of sawdust to remove antibiotics like penicillin from water
By the end of today, wastewater treatment plants will have received about 11 billion litres of wastewater - enough to fill 4,400 Olympic-sized swimming pools. This wastewater contains a considerable amount of antibiotics which will not be removed before the wastewater is discharged into lakes and rivers.
As we know, the consumption of antibiotics for human and veterinary use has increased drastically in recent years, causing antimicrobial resistance to be recognised as "one of the biggest threats to global health". The release of antibiotics into aquatic ecosystems from household, hospital, industrial and agricultural wastewaters leads to serious environmental issues and adverse effects on human and animal health.
What this means is that bacteria occurring naturally in the environment become exposed to antibiotics and become resistant over time thereby, rendering antibiotics ineffective in treating infections. The World Health Organisation estimates that antibiotic resistance could lead to the death of 10 million people annually by 2050 if the problem is not tackled.
There is a lack of effective treatment methods in response to water contamination with drugs and the aim of our research in the School of Pharmacy at Ulster University is to develop a cheap and effective method for removing antibiotics from water. Some conventional techniques such as chlorination may even exacerbate the problem by forming unknown intermediates/by-products and contributing to the antimicrobial resistance problem.
Adsorption processes are widely adopted for the removal of metals, dyes, and petrochemical products from water, though production and regeneration costs of some adsorbents, such as activated carbon, remain high. Sawdust is a waste product of wood processing and is an ideal material because it is cheap, easily accessible and has been proven to remove toxic chemicals from water. Lignocellulosic waste materials such as sawdust, wheat straw and sugarcane bagasse are the most promising alternative bio-adsorbents. These materials have been used effectively to remove pesticides and pharmaceuticals from ground and surface waters. Additionally, they are non-toxic, cheap, readily-available and environmentally-friendly materials.
This treatment method is based on a mechanism called adsorption. In simple terms, adsorption is the attachment of the pollutant to the surface of a material. Our research has explored the potential of sawdust to remove several antibiotics from water, namely penicillin, meropenem, ofloxacin and ciprofloxacin. These widely used antibiotics have been identified and highlighted by the World Health Organisation as being in danger of losing their efficacy.
When these antibiotics are exposed to sawdust through the process of adsorption, it is able to successfully remove up to 80% of the antibiotics. 100% is the target and this can be achieved by improving the efficiency of the sawdust through various chemical modifications. This will be the sawdust redemption to the antibiotic problem in water.
The views expressed here are those of the author and do not represent or reflect the views of RTÉ