**7. Example of pentachlorophenol phytoremediation**

### **7.1 Typha genus**

The Typha genus as a macrophyte always shows the advantage of development and growth under various climatic conditions, and function as bio-filters to protect lakes, estuaries and varied water bodies (**Table 1**) [86]. However, although it has been shown that Typha can tolerate and remove various xenobiotics: chlorinated benzenes, carbamazepine, diazinon, permethrin, chlorpyrifos and metformin (**Figure 5**) [87]. The two processes of phytoremediation and bioaugmentation are both biological methods used in PCP remediation process. Phytoremediation is a rapidly developing method that uses plants to reduce, degrade, assimilate and metabolize environmental pollutants such as hydrocarbons, pesticides, etc. [88].

Several studies have successfully evaluated phytoremediation of pollutants (i.e. nutrients, heavy metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls) by mangroves [89].

#### **7.2 Duckweed**

This technology is suitable for sites with shallow contaminants [90]. They indicate that fullscale and pilot studies are going to demonstrate the promise and drawbacks of plant application for remediating hazardous waste in terrestrial and sediments. Aquatic media have been presented high quality and effective responses for phytoremediation especially for organic contamination.


#### **Table 1.**

*Examples of plants use in phytoremediation process.*

**Figure 5.** *Different phenomena of phytoremediation for Typha angustifolia plant.*

Duckweed is composed of one or few leaves called fronds and a single root or rootlet with no stem, and the next generation generate through vegetative propagation [91]. Therefore, Lemnaceae is tremendously suitable for the phytoremediation of sewage. Duckweed is a highly efficient accumulator of various pollutants in surface water bodies and extensively used for xenobiotics, inorganic matters, HMs and pathogens removal from LW [10, 16, 23, 91]. Above all, duckweed needs plenty of nutrients to maintain its growth and development, which is beneficial for nitrogen and phosphorus recovery from LW. For example, Lemna sp. could remove 90% of PCP in constructed wetland with typha angustifolia [65].
