## 5 Emerging Risks and Gaps  
New technologies could involve human and environmental risks. Therefore, phytotechnologies should be used knowledgeably and stringently screened before environmental release. Phytoremediation is an exciting field of research growing day by day, at the crossroads of agronomy, environmental engineering, ecology, economy, and social sciences; therefore, transdisciplinary work is highly encouraged. It is crucial to know the destination of pollutants in plants to make decisions about the fate of metals in downstream processing, which would be incorporated into bioenergy production. In the same way, understanding the pollutants' fate in plants allows us to estimate the possible transfer of metals in some by-products or residues during biofuel production. The use of edible plants during phytoremediation is an additional risk. Therefore, the use of non-edible crops must be encouraged in bioremediation technologies [170]. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Plant** & **Elements Recovered** & **Condition** & **Additional Benefit** & **Reference** \\ \hline _Thluspi caerulescens_ & & & Recycling of the bottom & \\ (Jord) and _Salix_ & Cd and Zn & Pyrolysis occurred under reducing conditions. & ash as fertilizer and production of energy & [168] \\ _viminals_ (L.) & & & derived from pyrolysis & \\ \hline \multirow{4}{*}{Higher plants} & Aqueous phase with N, & & & Generation of bio-crude & \\  & P, and K, and & Pyrolysis or & for upgrading to & \\  & solid residue & hydrothermal liquefaction & advanced biofuels & \\  & containing HMs & & & \\ \hline \multirow{4}{*}{Contaminated plants and energy crops} & \multirow{4}{*}{HMs} & Thermochemical processes & & \\  & & (pyrolysis, gasification, & \\  & and energy crops & combustion, & heat recovery & \\  & & and liquefaction) & & \\ \hline Mixtures of biomass & C, H, O, N, P, Cl, S, & & & \\  & and HMs & Pyrolysis & solid biochar & [169] \\ \hline Woody gymnosperm, & & & & \\ angiosperm, and & Cd, Cu, Pb, Zn, Co, Cr, & & & \\  & herbaceous plants & and Ni & & \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Viable and feasible options for the treatment of potential toxic-metal-enriched plants produced by phytoremediation. As a global trend, many authors have stated that phytoremediation must focus on the recent advances in food production, dissipation of pollutants, biomass valorization, energy production, ecological balance, and knowledge areas regarding social welfare with potential applications and benefits in the environmental and agri-food industries, i.e., several well-designed, large-scale, and long-term field trials must be carried out. The above implies the use of dozens of uncontrolled variables, and therefore the design and management of phytoremediation systems become complex, highlighting the need for multiple expert collaborative works. Additionally, the effect of working together with cutting-edge technologies such as nanotechnologies along with phytoremediation has been studied to dissipate pollutants from contaminated soils. Still, most of the results are preliminary or were produced during short-term laboratory studies [171]. Food security, water, energy, and pollution remediation are high-priority issues regarding sustainable development, and all of them are inextricably linked [172]. In recent decades, unexpected and common contaminants in soil, water, and air have threatened food security and human and environmental health. New environmentally friendly and cost-effective strategies are in the experimental phase and are scarce or not available for real-life use. An accurate mapping of soil, water, and air pollution is missing to prevent the transfer of ubiquitous pollutants into the food chain. This map is necessary to design and implement suitable remediation strategies that could use bioremediation technologies such as phytoremediation, bioaugmentation, or biostimulation as cost-effective strategies. According to Rai et al.