## 5 Conclusions  
Obtained results show that CWs can be a suitable option for the removal of different families of phenolic compounds. In fact, CWs systems, assembled in controlled laboratory conditions, showed to be able to remove totally, in the case of alkylphenolic compounds, or in high amounts, in the case of a chlorophenolic compound, these contaminants from a contaminated stream water. In addition, in both experiments, CWs systems were able to maintain high removal rates of organic matter and nutrients and the presence of either contaminant, alone or in a mixture, did not interfere with this removal process. Therefore, phenolic compounds presence did not affect significantly CWs functionality.  
The microbial community in CW substrates was composed mostly by bacteria. Richness, diversity or dominance of microbial community was not affected by the presence of alkylphenolic compounds (a mixture of NP and OP), but the presence of PCP cause a decrease in microbial community diversity. Microbial community characterization in CW plant root bed substrate showed several phyla commonly present in CWs substrate, namely those characteristic of _P. australis_ rhizosphere, and those commonly associated with contaminants degradation. Moreover, there was a selection, at least at the genera level, of bacteria with capacity to degrade the select phenolic compounds. Different bacteria were observed comparing systems exposed to alkylphenol and chlorophenol compounds, bacteria that probably contributed for compounds biodegradation, decreasing their amount in CW systems. Promotion of the presence of these bacteria, through for instance, bioaugmentation strategies, could be an option to increase the performance of CWs for the remediation of water contaminated with phenolic compounds, particularly for PCP which showed lower degradation rates, deserving further research.  
The present study contributes to increase the knowledge regarding CWs performance and to promote the use of this nature-based solution for the treatment of waters contaminated with different families of phenolic contaminants, a relevant issue taken in consideration their negative impact on the environment. CWs can contribute to eliminate or reduce that impact, protecting ecosystems.  
**Supplementary Materials:** The following are available online at [[https://www.mdpi.com/2073-441/13/5/715/s1](https://www.mdpi.com/2073-441/13/5/715/s1)]([https://www.mdpi.com/2073-441/13/5/715/s1](https://www.mdpi.com/2073-441/13/5/715/s1)), Figure S1: Schematic graphical assembly of CWs with a flow recirculation and a modified bed used in both experimental works, Figure S2: The experimental design (a) and sediment sampling in each CW (b), Figure S3: (A) Abundance of the major phyla and (B) classes with abundance \(>1\%\) of Archaea across the different CWs systems substrates, irrigated along eight weeks with Ribeira de Joane water not doped (control) or doped with NP and OP. Samples collected at the beginning (T0) and at the end of the experiment (T8) (\(n=3\)), Figure S4: (A) Abundance of the major phyla and (B) classes with abundance \(>1\%\) of Archaea across the different CWs systems substrates, irrigated along eight weeks with Ribeira de Joane water not doped (control) or doped with PCP. Samples collected at the beginning (T0) and at the end of the experiment (T8) (\(n=3\)),