More and more studies show that the remains of drugs we consume end up in water: rivers, drinking water and groundwater. The Synthetic and Industrial Chemistry Research Group of the Public University of Navarra (UPNA) has developed two collection systems for these drug residues to prevent drug residues from reaching groundwater, surface or consumption. They have focused mainly on non-steroidal anti-inflammatory drugs, since they are used not only in humans but also in veterinary medicine.
Double laminar hydroxides have been used for the collection and separation of these contaminants from water, which when immersed in contaminated water remain in the layers of this material. They have developed a methodology based on the circular economy. In fact, hydroxides have been generated by using salt slags (industrial waste from aluminum recycling). Thus, a dangerous and apparently useless waste has achieved an environmental application. Water pollutants are associated in this material.
Two ways to reduce the presence of contaminants in water have been investigated: on the one hand, adsorption processes, in which drugs are separated from water by chemical and physical interactions, adhering to the laminar surface of double hydroxide, and on the other, photocatalytic processes. In the latter, double laminar hydroxides change from titanium and iron and, with the help of energy supplied by ultraviolet light, act as catalysts to degrade new contaminants. According to the researchers, it has been shown that aluminum present in hazardous waste can become a value-added product and be used in contaminated water treatment processes. In addition, they highlight the advantage that the waste is no longer dangerous after its cleaning and extraction of aluminum.