Lead and Antimony Removal from Contaminated Soil by Phytoremediation Combined with an Immobilization Material

Abstract

Phytoextraction (PE) requires long periods for the removal of heavy metals from contaminated soil, even when using a hyperaccumulator. Thus, we designed a new phytoremediation technique called phytosuction separation (PS-S), in which a material that immobilized heavy metals was placed onto contaminated soil and plants were grown on the upper layer of this material. Heavy metals in the soil were transported toward the upper layer by the water suction effect of the roots and immobilized by the material and then removed from the contaminated soil. A pot experiment was conducted to evaluate the ability of PS-S to remove lead (Pb) and antimony (Sb) from the soil. We found that evapotranspiration and shoot biomass were significantly higher in plants grown using PS-S than those grown using PE. The pot experiment demonstrated that PS-S was effective in removing Pb and Sb, and the concentrations of Pb and Sb removed by PS-S were 8-25 and 69-533 times higher than that removed by PE, respectively. Sb could be effectively removed by PS-S from contaminated soil where the concentration of Sb removed corresponded to 166-380% of water-soluble Sb in contaminated soil. This study clearly demonstrated that PS-S was effective in removing Pb and Sb from the contaminated soil and would be particularly useful for removing elements with high mobility.

Immobilization of Lead Migrating from Contaminated Soil in Rhizosphere Soil of Barley (Hordeum vulgare L.) and Hairy Vetch (Vicia villosa) Using Hydroxyapatite

“…Lead concentrations in the shoots of barley and hairy vetch grown in the soil with RC with the hydroxyapatite were within similar levels as those of plants grown in non-contaminated soil [ 20 , 39 , 40 ]. These results indicate that the plant growth in the soil with the RC with the hydroxyapatite was not reduced by the lead that migrated from the contaminated soil.…”

Behaviour of nutrients released from crystalline minerals of artificial potassium silicate fertilizer and their supply to the Japanese mustard spinach (Brassica rapa var. perviridis)

“…The amount of nitrogen fertilized was the same even in the control treatment. The increase in plant growth increases evapotranspiration (Katoh et al, 2016). Moreover, nitrate can easily migrate to the soil via water migration (Gaines & Gaines, 1994).…”

Improving capacity for phytoremediation of Vetiver grass and Indian mustard in heavy metal (Al and Mn) contaminated water through the application of clay minerals

“…A review by Paz-Ferreiro et al (2014) confirmed the use of several amendments such as biochar and compost in combination with phytoremediation plants to achieve better remediation results. The approach of using immobilisers to improve phytoremediation has been tested in the laboratory showing increased phytoextraction of Pb and Sb, up to 533 times higher than using plants alone without amendments (Katoh et al 2016).…”