**7.3 Phytoremediation by microalgae**

Microalgae could be adapted to a variety of water bodies and were extensively used to treat effluent [9]. Microalgae-based systems can absorb organic matter and nutrients from water bodies to meet their own growth needs [16]. Meanwhile, microalgae store various high value-added nutrients and chemical raw materials such as proteins, lipids, polysaccharides, vitamins, and beta-carrots, which could produce high-addition products such as biofuels and health products after purification [92]. Microalgae are also successfully employed to remove various antibiotics from LW. Initially, photobioreactors based on microalgae could remove 95% of doxycycline (DOX) and 93% of OTC from piggy wastewater [93]. In recent years, various studies have a smack at removing hormones and pathogens from LW via microalgae.

Phytoremediation by aquatic plants Aquatic plants have confirmed to be available materials for phytoremediation research, and dissimilar kinds of hydrophytes such as duckweed, water lettuce, water hyacinth, and watermilfoil were widely applied to phytoremediation of LW [10, 16].

*Potential of Aquatic Plants for Pesticide Removal in Wastewater: A Case Study… DOI: http://dx.doi.org/10.5772/intechopen.107064*

**Figure 6.** *The main mechanisms of phytoremediation- bioaugmentation process; case of constructed wetland.*

#### **7.4 Phytoremediation by constructed wetlands**

Biological, physical, and chemical processes interactions between water and substrate, macrophytes, and associated microorganisms are the foundation of erasing pollutants from wastewater in constructed wetlands (CWs) (**Figure 6**) [98]. Eventually, although wetland plants could widely involve in removing organic matters from LW, research by [99] showed that the elimination performance of that did not alternate considerably in seasons while plants increase became reserved. It may be concluded that the elimination of natural topics from LW special from nutrients, which relies upon at the participation of microorganisms that distribute withinside the rhizosphere of vegetation and substrate of CWs. The organic technique is the important pathway to remove HMs from LW in CWs, and the performance of metals elimination via way of means of CWs varies extensively related to the neighborhood weather conditions, plant species, concentrations, and species of heavy metals [100].

In the end, the aerobic condition is more efficient than anaerobic on the biodegradation of antibiotics and hormones, and benefit from this, antibiotics and hormones in LW can be greatly reduced [101]. In order to hold the sustainable improvement of the ecological environment, the usage of aquatic plant life that applied to manipulate LW is rather important. Foremost, macrophytes including duckweed and water hyacinth had been used for farm animals feed because of better degrees of proteins, starches, and celluloses, and accomplished outstanding results.
