available regarding the dynamics of enantiomers of pharmaceuticals in CWs. Only a
limited number of chiral drugs have been investigated to date [27]: atenolol,
citalopram, fluoxetine, ibuprofen, metoprolol, nadolol, pindolol, propranolol,
salbutamol and sotalol. Different removal efficiencies were observed for the Sand R-enantiomers of most of these compounds, but little else is known.
In general, even though microbial degradation is a key process driving the
removal of pharmaceuticals in CWs, detailed process understanding is lacking.
Answers to questions such as: which species (degraders) degrade which compounds;
which transformation products are being formed and what are the biotransformation
pathways; and are the processes driven by co-metabolism and/or catabolism are
expected in the future.
4 Constructed Wetlands a Nature-Based Solution
and Important Ecotechnology for a Green Transition
CWs have been used for decades as a valid alternative to treat wastewater for small
(rural or urban) communities. Their historical application and development has
followed different trends in different parts of the world [29]. Currently, we are
observing a potential new phase. As climate change and environmental degradation
are an existential threat to Europe and the world, a European Green Deal has recently
been proposed [108]. This deal provides a road map with actions to (1) boost the
efficient use of resources by moving to a clean, circular economy; and (2) restore
biodiversity and cut pollution. For that, investment in environmentally friendly
technology is expected, namely, in nature-based solutions. CWs are one of the
identified nature-based solutions that can contribute to water purification and
waste treatment, as well as for resources recovery [18, 109]. Naturally, as OECD
calls for better policy approaches to manage pharmaceutical residues [4], we can
expect an increased pressure on the usage of CWs to address not only classical
pollutants but also pharmaceuticals and other contaminants of emerging
concern [55].
Even though CWs require a higher footprint than conventional systems (roughly
CWs are designed with 1–20 m
2 per person equivalent), these nonetheless represent
a suitable toolbox to address pharmaceuticals contamination. But it is also perceived
from different works, namely, performed in the laboratory, that there is potential to
optimize the ecotechnology to achieve better performances for pharmaceuticals
treatment. Potentially for its application as polishing step to conventional systems,
or even as the final step in treatment tailored to specific users, such as healthcare or
hospital facilities [27]. In spite of the potential, CWs application for such purpose is
rather limited. This implies that the knowledge gathered in these review papers
assess how CWs built to treat different types of wastewater perform in regard to
pharmaceuticals. We are missing more studies on designs dedicated to improve
pharmaceutical removal. Nevertheless, there is potential to apply optimized CWs
406
P. N. Carvalho
limited number of chiral drugs have been investigated to date [27]: atenolol,
citalopram, fluoxetine, ibuprofen, metoprolol, nadolol, pindolol, propranolol,
salbutamol and sotalol. Different removal efficiencies were observed for the Sand R-enantiomers of most of these compounds, but little else is known.
In general, even though microbial degradation is a key process driving the
removal of pharmaceuticals in CWs, detailed process understanding is lacking.
Answers to questions such as: which species (degraders) degrade which compounds;
which transformation products are being formed and what are the biotransformation
pathways; and are the processes driven by co-metabolism and/or catabolism are
expected in the future.
4 Constructed Wetlands a Nature-Based Solution
and Important Ecotechnology for a Green Transition
CWs have been used for decades as a valid alternative to treat wastewater for small
(rural or urban) communities. Their historical application and development has
followed different trends in different parts of the world [29]. Currently, we are
observing a potential new phase. As climate change and environmental degradation
are an existential threat to Europe and the world, a European Green Deal has recently
been proposed [108]. This deal provides a road map with actions to (1) boost the
efficient use of resources by moving to a clean, circular economy; and (2) restore
biodiversity and cut pollution. For that, investment in environmentally friendly
technology is expected, namely, in nature-based solutions. CWs are one of the
identified nature-based solutions that can contribute to water purification and
waste treatment, as well as for resources recovery [18, 109]. Naturally, as OECD
calls for better policy approaches to manage pharmaceutical residues [4], we can
expect an increased pressure on the usage of CWs to address not only classical
pollutants but also pharmaceuticals and other contaminants of emerging
concern [55].
Even though CWs require a higher footprint than conventional systems (roughly
CWs are designed with 1–20 m
2 per person equivalent), these nonetheless represent
a suitable toolbox to address pharmaceuticals contamination. But it is also perceived
from different works, namely, performed in the laboratory, that there is potential to
optimize the ecotechnology to achieve better performances for pharmaceuticals
treatment. Potentially for its application as polishing step to conventional systems,
or even as the final step in treatment tailored to specific users, such as healthcare or
hospital facilities [27]. In spite of the potential, CWs application for such purpose is
rather limited. This implies that the knowledge gathered in these review papers
assess how CWs built to treat different types of wastewater perform in regard to
pharmaceuticals. We are missing more studies on designs dedicated to improve
pharmaceutical removal. Nevertheless, there is potential to apply optimized CWs
406
P. N. Carvalho