## 2 Pharmaceuticals and Personal Care Products (PPCPs) in the Ecosystems
### Combined Chemical Engineering-Biological Methods
#### 2.3.2 Constructed Wetlands
Vegetables also generate a microhabitat that regulates light and temperature, favors sedimentation and prevention of the medium clogging in vertical flow systems [323]. Useful plants to constructed wetlands are: aquatic species, including free-floating species such as _Nymphaea_ sp., _Eichlornia_ sp., _Lemma_ sp., _Azolla_ sp., _Salvinia_ sp., _Pistia stratiotes_, _Eichlornia crassipes_, etc., and helphytes as _Sagittaria_ sp., _Juncus_ sp., _Phargmites_ sp., _Thypha_ sp., _Scirpus_ sp and _Schooneplectus_ sp. [259; 324; 325]. In many countries, local plant, especially ornamental plants are used, with an aesthetic and commercial added value (Figure 5B). Some examples are: _Cannae liliies_, _Canna indica_, _Heliconias_ sp., _Zantedeschia_ aethiopica_, etc. [259; 260; 323]. Microorganisms seem to be less inhibited by PPCPs in constructed wetlands, because plants stabilize and activate the microbial communities by supplying nutrients and oxygen and an adequate microhabitat or biofilms [326; 327] increasing aerobic degradation and nitrification [323]. Overall, and as it happens in other full scale systems (active sludge, bioreactors, etc. ), the presence of a specific organic pollutant activates and favors certain microbial genomic sequences that may be related to the degradation of pollutants [200; 327]. Thus, [200] showed that IBU reduces the diversity of the fungal community, especially within unplanted wetlands. The species enhanced in abundance after IBU exposure were _Aspergillus_ sp. and _Trichoderma_ sp., suggesting a relationship of these species with the degradation of this anti-inflammatory drug. The presence of plants in CW had a remarkable effect on the structure of microbial community, helping buffer against the stress associated with CFN exposure [200]. Other study indicated that the presence of ciprofloxacin had an adverse effect on the bacterial communities in CW, initially reducing their ability to assimilate anthropogenic carbon-based compounds, but the bacterial communities returned to normal functioning after a 25 weeks acclimatization period [328]. Ongoing monitoring and hydrological and vegetation management are essential to maintain site habitat diversity and its functionality due to the natural dynamics of populations that are established over time in all the living components of a CW. As previously mentioned, the microbiome associated to plants seems to have a fundamental role in their response to stress situations under CW conditions (Figure 6). In fact, [282] suggests the application of the potential endophytes to improve the performance of these systems. Thereby, plant-endophyte synergism in CW enhances the remediation of nutrients [329; 330], heavy metal [30; 245; 331], metalloids [332], textile industrial effluents [333; 334] and rural domestic water [318]. Likewise, bioaugmentation with denitfifying strains can activate the non-endophytic microorganisms that are associated with the rhizosphere, favoring the denitrification of nutrients [335] altering the soil microbial community structure by changing the species of nitrogen-related bacteria, and establishinga new bacterial community balance in situ [300; 336; 337]. In some studies, it has been proven that the remediation effect of bacteria is more important than that of plants [338]. There are few studies analyzing the degradation of PPCPs in CW emphasizing the plant-microorganism synergy effect. Some antibiotics, such as DFC and SMX, have been partially degraded in CW implying degrader endophytes [339; 340]. Inoculation of an estradiol-degrading bacterium in a CW favors the degradation of this hormone and modifies the bacterial community of the biofilm where it is stabilized [341]. As far as we know, WRF has not been used in PPCPs-degrader constructed wetlands probably because an aquatic system is not the most suitable habitat for the development of these organisms. However, whole-cell has been used successfully in _P. ostreatus_ bioreactors, for water treatment, even under bacterial stress [342]. Additionally, _P.