The effects of hematite nanoparticles on phytoavailability of arsenic and corn growth in contaminated soils

Abstract

This study was carried out to assess the effects of hematite nanoparticles (α-Fe2O3) on the motility and phytoavailability of arsenic in contaminated soils and corn growth. A factorial experiment was conducted using a completely randomized design and three replications. The examined factors were the application rates of hematite nanoparticles (0, 0.05, 0.1 and 0.2%) and the levels of soil arsenic (0, 6, 12, 24, 48, and 96 mg/kg). Before sowing of corn seeds, the concentrations of soil available arsenic were measured in all soil samples. Corn plant was used as a biological indicator of arsenic phytoavailability and 75 days after sowing, it was harvested, and dry weights of aerial parts and roots and concentrations of arsenic and phosphorus of these parts were measured. The results showed that the concentration of soil available arsenic and arsenic concentrations of root and aerial parts increased as the concentration of soil total arsenic increased. Contamination of soil by arsenic increased the concentration of phosphorus in root but decreased it in the aerial parts of corn. In contaminated soils, the application of hematite nanoparticles significantly decreased the concentrations of arsenic in soil and in root and aerial parts of corn and increased the dry weights of root and aerial parts. But in uncontaminated soils, the application of hematite nanoparticles decreased the concentration of phosphorus and the dry weights of root and aerial parts of corn.