Application and research progress of Hydrilla verticillata in ecological restoration of water contaminated with metals and metalloids

Abstract Hydrilla verticillata (L.f.) Royle is a widely distributed aquatic weed having prolific growth habits and a wide range of habitat. It can tolerate a wide range of physical and chemical conditions of water and can survive in low nutrient supply. Hydrilla is a potential accumulator of several metals and metalloids. The accumulation potential of Hydrilla plants is attributable to induced synthesis of thiol (-SH) containing ligands like glutathione and phytochelatins. Further, the uptake of metal(loid)s from both roots and leaves and movement in acropetal and basipetal directions allows plants to take up large quantity of metal(loid)s in short time span. Secondarily, antioxidant system is comprising of enzymatic and non-enzymatic components was found to rescue plants from metal(loid) induced oxidative stress. The used biomass of Hydrilla can be further utilized for composting, briquetting, pyrolysis and gasification. The high calorific fuel obtained from Hydrilla was found to have high heating value (44.06 MJ/kg) and low oxygen content (