The constant development of our society and its urbanization has contributed for pollutants spreading, including pharmaceuticals, compounds that have been used to tackle several human and veterinary diseases. However, their intensive consumption and inadequate use has led to their presence in different environmental matrices, endangering ecosystems functioning and impacting the organisms that inhabits therein. Wastewater treatment plants (WWTP’s) are one of the major sources of pharmaceuticals in the environment as these facilities were not designed to remove these compounds. Until recently, pharmaceuticals and their active metabolites were not under any regulation or legislation, but then, the Directive 2013/39/EU was implemented, in which some pharmaceuticals were considered as priority substances to regulate in the field of water policy, being included in a Watch List. Recently, the urban wastewater treatment directive under the European Union (EU) zero-pollution action plan was revised, establishing that, until 2045, a broad range of micropollutants (including pharmaceutical compounds) has to be removed by WWTP’s. Thus, there is a need to develop sustainable solutions to couple in WWTP’s facilities, in which less modifications in their actual structure and low interference in their daily processes is ideal. Keeping in mind the EU’s zero-pollution action plan and relying in more sustainable processes, bioremediation, more specifically, the use of specialized microorganisms with metabolic machinery to biodegrade pharmaceuticals can be presented as a suitable and sustainable solution. Most WWTP’s conventional biological processes (e.g. activated sludge) has a very specific microbial community that is highly specialized to degrade organic matter and reduce the nitrogen and phosphorus from the influent. These biological reactors operate with optimized hydraulic retention time, sludge retention time and food to microorganism’s ratio, which usually are not ideal for the biodegradation of more complex molecules, such as pharmaceuticals. Thus, the use of specialized microorganisms as a solution to biodegrade pharmaceuticals should be considered in a tertiary or quaternary treatment, in a separated station. The MICROCHAR project aims to develop structures of biochar immobilized microorganisms, that have capacity to degrade different pharmaceuticals, to be implemented in WWTP’s tertiary or quaternary treatment, responding to the new urban wastewater treatment directive. To start, bacterial strains previously isolated from enriched cultures inoculated with activated sludge, and with capacity to biodegrade two pharmaceuticals (paroxetine and bezafibrate), will be used. In addition, bacterial strains from CIIMAR Microbial Culture Collection (CM2C), able to degrade different pollutants (e.g. hydrocarbons and pharmaceuticals) will be tested against different pharmaceuticals (e.g. ketoprofen and atorvastatin as representative of different therapeutical classes), to assess their biodegradation potential. Trials will be carried in a first step using synthetic media, and the best degrading strains will be tested in real wastewater effluent (collected after the secondary biological treatment), individually and together as a consortium, also assessing their potential to biodegrade different or /and a mixture of pharmaceuticals. Then, the potential to form aggregates, alone and as a consortium, will be evaluated for the previously selected microorganisms, followed by the immobilization of the bacterial aggregates within biochar structures. Finally, microcosms experiments will be assembled to validate the biodegradative potential of the biochar immobilized bacterial aggregates, using effluent from a WWTP’s facility, collected after the secondary biological treatment.
The MICROCHAR team has a strong background in the development of nature-based solutions (such as bioremediation) to degrade different organic pollutants. In addition, the researchers from MICROCHAR have high expertise in microbiology, environmental chemistry, and wastewater treatment and management, which is essential to execute the project. With MICROCHAR project, it will be possible to develop a sustainable and ecofriendly technology, with low environmental impacts and low operational costs, suitable to be applied in WWTP’s tertiary or quaternary treatments. These structures can be mobile and can be easily renovated.
The results from MICROCHAR project can contribute for the development of efficient tertiary or quaternary treatment to apply in WWTP’s, in agreement with the EU’s zero-pollution action plan and to accomplish the sustainable development goal 6 – Clear water and sanitation, by ensuring availability and sustainable management of water and sanitation for all.
