# Advancements in Phytoremediation Research in South Africa (1997-2022)
## 3 Results and Discussion
### Examples of Successful Phytoremediation Projects in South Africa  
South Africa is a country contending with various environmental challenges, especially the impact of mining activities on the environment. In the pursuit of sustainable environmental management and remediation, the government of South Africa has come up with different environmental policies and regulations that aid the advancement and implementation of phytoremediation as an innovative tool for environmental restoration. The policy encourages research, investment, and implementation of phytoremediation technology in environmental remediation in South Africa [46,47]. This is made possible by providing incentives for research through grants and various funding mechanisms for the restoration of the environment [48]. Researchers in South Africa have taken advantage of these opportunities to promote phytoremediation technology. Some of the identified plant species for the restoration of contaminated environment in South Africa are shown in Table 4. \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Method** & **Plant Species** & **Pollutants Removed** & **References** \\ \hline Phytostabilization and Phytoextraction & \begin{tabular}{c} _Cyperus haspan_, _Schoenoletus_ \\ _cormbosus_, _Tipha capensis_, _Pragmites_ \\ _australnis_, _Cynodon dactylon_, _Cyperus_ \\ _marginatus_, and _Juncus effusus_ \\ \end{tabular} & Aluminium, Iron, and Manganese & [2] \\ \hline Rhiziltration & \begin{tabular}{c} _Pragmites australis_ and _Kyllinga_ \\ _nemoralis_ \\ \end{tabular} & Cadmium, Chromium, Copper, Nickel, Lead, and Zinc & [8] \\ \hline Rhiziltration & \begin{tabular}{c} _Pragmites australis_ \\ \end{tabular} & Total kjeldahl Nitrogen & [9] \\ \hline Phytoextraction & \
\begin{tabular}{c} _Helianthus annuus_ \\ \end{tabular} & Cd, Cu, Fe, Mn, Ni, Pb, and Zn & [42] \\ \hline Phytoextraction &
\begin{tabular}{c} _Pragmites karka_ \\ _Veteveria nigritana_ \\ \end{tabular} & Fe, Mn, Pb, Mg, and Cr & [4] \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Plant species in phytoremediation of the polluted environment in South Africa. Figure 5: Bibliographic coupling analysis of journals. _Eichhornia crassipes_ (water hyacinth) is an aquatic ornamental flower native to the Amazon Basin in South America and is now present in most continents. Although water hyacinth is considered an invasive aquatic plant, it has been used as a fertilizer and charcoal briquettes and in water treatment [60; 61; 62]. Reports have shown that the growth of water hyacinth in eutrophic water is beneficial. The plant consumes an enormous amount of nutrients (such as phosphorus, nitrogen, and potassium) from water, and a fraction of this is stored, while the leftovers are used for growth. [PERSON] et al. [22] capitalized on the potential of water hyacinth as a remediation tool for the removal of phenols, heavy metals, and mirex, with restricted consequences on plants. Hartbeespoor Dam, located in the North West Province of South Africa, is polluted with acid mine drainage containing heavy metals [63]. The [PERSON] et al. [22] report showed that water hyacinth grown in a vessel containing Hartbeespoor Dam water reduced the phosphate and nitrate concentrations by 93.8% and 87.8%, respectively, within 4 days. Consequently, _Eichhornia crassipes_ can be deployed as a remediation tool for phytoextraction of nutrients without any harmful effects on plant health. In addition, _Chrysopogon zizanioides_ (vetiver grass) is a hyperaccumulator originally from India and is also found in South Africa [49; 64]. Vetiver grass can grow up to a height of 5 ft, and its root is 7-13 ft deep. The stems are tall, and the leaves are somewhat rigid, thin, and long with brownish flowers [65; 66]. Vetiver grass has been used in the treatment of industrial wastewater and soil reclamation in many countries [64; 67]. [PERSON] et al. [49] reported the performance of vetiver grass in phytoextraction of chromium under hydroponic conditions.