The group of Environmental Chemical Analysis of University Institute of Environmental Studies and Natural Resources of the University of Las Palmas de Gran Canaria (ULPGC) has evaluated the presence of 11 compounds in 3 wastewater treatment plants in Gran Canaria, within the ADAPTaRES project that studies the presence of pharmaceutical waste in the aforementioned treatment plants.
This work has been turned into a research article where the efficacy of the treatments of the three treatment plants (WWTP) in the elimination of these pollutants, showing that they are efficient and, therefore, that the water can be reused after purification. Therefore, the final objective of the Project is achieved, which is to promote reuse of sewage water as a strategy for adaptation to climate change in Macaronesia.
The research work is signed by Rayco Guedes Alonso, Javier Pacheco Juárez, Sarah Montesdeoca Esponda, Zoraida Sosa Ferrera, José Juan Santana Rodríguez and Gilberto Manuel Martel Rodríguez, the latter, an ITC researcher and coordinator of the ADAPTaRES Project.
The article analyzes the presence of pharmaceutical compounds in waste and regenerated water from the wastewater treatment plants (WWTP) of the Southeast and Santa Lucía, both in Gran Canaria.
The highest concentrations detected, especially in the water entering the treatment plants, were of stimulants such as caffeine and the nicotine, and of non-steroidal anti-inflammatory drugs such as ibuprofen.
The waters resulting from the treatment of these WWTPs were analyzed monthly for two years with the aim of demonstrating their quality and thus promoting their reuse. To guarantee the quality and safety of these waters, it is necessary to demonstrate that they do not present emerging pollutants such as drugs, or that they are in concentrations that are not a risk to human health or ecosystems. Likewise, the study carried out made it possible to evaluate whether these types of pollutants are eliminated in WWTPs, and to verify whether conventional and natural treatment technologies are equally efficient when it comes to eliminating drugs present in wastewater.
Two of the selected WWTPs have conventional purification technologies and treat the waters of densely populated areas. Both use a process based on active sludge as a secondary treatment, which consists of degrading organic matter through bacteria. Subsequently, to improve the quality of the treated water, one of them applies ultrafiltration and the other, microfiltration and reverse osmosis processes as tertiary treatments.
On the other hand, the third WWTP studied consists of a natural purification system (SDN) based on wetlands and treats wastewater from a small rural area. In this type of facility, the natural capacity of bacteria and plants is used to purify residual water, so that the energy consumption of this type of facility is practically nil. In addition, endemic plants from the Canary Islands are used in said WWTP, so the visual and ecological impact is minimal.
Although the treatment plants studied are completely different, since one is a conventional treatment plant that treats the waters of a densely populated area of the island (Southeast of GC) and the other is a natural treatment plant that treats the waters of a small rural nucleus (Santa Lucía), the concentrations of pharmaceutical residues detected at the entrance were similar.
The reclaimed waters studied in this Project are a very valuable resource in semi-arid areas such as the Canary Islands, since they produce very little environmental impact and risks to human health. Therefore, its use can be implemented as an adaptation strategy to climate change.