Phytoremediation of cesium-contaminated soils using Sorghum bicolor, Albizia falcataria, Amaranthus viridis, and Vetiveria zizanioides in tropical environments

Abstract

Radioactive cesium (Cs-137) contamination in soil presents serious environmental and health concerns due to its long-lasting presence and high mobility. Conventional remediation techniques are often expensive and technically complex, prompting the need for more sustainable approaches. This study investigates the potential of phytoremediation as an environmentally friendly approach for soils contaminated with stable isotope Cs-133, using Sorghum bicolor, Albizia falcataria, Amaranthus viridis, and Vetiveria zizanioides under controlled conditions. The results indicate that a mong the four species studied, Amaranthus viridis and Sorghum bicolor achieved the higher bioaccumulation and translocation factors, with Amaranthus viridis producing a peak biomass of 125 g at 100 ppm and Sorghum bicolor reaching 180 g at 50 ppm. All species showed translocation factor values greater than 1, confirming their ability for phytoextraction. However, while bioaccumulation factor values exceeded 1 at cesium concentrations below 50 ppm, they decreased at higher concentrations, suggesting a threshold for effective uptake. These findings indicate that Amaranthus viridis and Sorghum bicolor are promising candidates for phytoremediation of cesium-contaminated soils, particularly at concentrations up to 50 ppm, offering valuable insights into sustainable radioactive waste management, especially in tropical settings.