RESUMEN
Phytoremediation is one of the important methods for restoring heavy-metal contaminated soils. Using high-biomass economic plants to restore heavy-metal contaminated soils can have both ecological and economic benefits, with great application prospects. Based on the analysis of current situation and existing problems of phytoremediation, we propose the advantages of high-biomass economic plants in contaminated soil remediation, and summarize the recent advances and mechanisms involved in absorbing heavy metals in high-biomass economic plants. Furthermore, the possible methods for improving the remediation efficiency of high-biomass economic plants are also discussed, to provide insights for improving the economic benefits of phytoremediation and promoting its widespread application in the future.
Asunto(s)
Metales Pesados , Contaminantes del Suelo , Biodegradación Ambiental , Biomasa , Metales Pesados/metabolismo , Investigación/tendencias , SueloRESUMEN
Coastal and inland saline-alkali soil is important reserve land resources. However, some parts of saline land are now under the threat of heavy metals such as cadmium (Cd), lead (Pb) and the light metal lithium (Li). Phytoremediation with halophytes could be the most economical and effective way to restore the contaminated saline soil. In this study, the growth, physiological and biochemical indexes and ion contents of halophyte Salicornia europaea under different concentrations of Cd (0-50 mmol/L), Pb (0-50 mmol/L) and Li (0-400 mmol/L) were investigated to evaluate the tolerance and accumulation of the metal contaminations. The results showed that plant height, fresh weight and dry weight of S. europaea decreased significantly with the increase of Cd and Pb concentration. Low concentration of Li (< 20 mmol/L) promoted the growth of S. europaea, while the growth of plants was inhibited under higher concentration of Li (> 20 mmol/L). The tolerance order of S. europaea to Cd, Pb and Li was Li > Pb > Cd. Cd, Pb and Li stresses may negatively affected Na and K uptake and transport in S. europaea to affect plant growth. In addition, the antioxidant enzyme system synergistically responsed to resist the oxidative toxicity of different ions. The contents of Cd, Pb, Li in roots and shoots of S. europaea also increased with the increase of treatment concentration. Furthermore, Cd and Pb contents in roots were significantly higher than in shoots, while more Li accumulated in shoots than in roots. The aforementioned results showed that S. europaea had strong tolerance along with a high accumulate ability to Cd, Pb and Li, indicating its application potential in restoring Cd, Pb and Li contaminated saline soil. This study laid a basis for further exploration of the tolerance mechanism of S. europaea to Cd, Pb and Li stresses, and gave a new perspective for the usage of S. europaea to remediate Cd, Pb and Li pollutants in high-salinity alkali soils.