توصيفگر ها :
: نانومواد , نانوذرات آهن , نانوذرات مغناطيسي , سميت نانوذرات
چكيده انگليسي :
The production and use of nanomaterials is a new field of science and technology that is increasingly developing. Due to the widespread use of nanoparticles in recent years, concerns about the possible release of nanoparticles and potential effects on living organisms have increased. The nanoparticles have entered the soil from different routes and affect the activity and diversity of the soil microbial community and plant performance. Ferrite nanoparticles, including nickel ferrite and magnetite nanoparticles, have recently received considerable attention due to their unique electrical, magnetic and optical properties. Ferrite nanoparticles are used in various fields such as targeted drug delivery, cell imaging, catalyst design for organic reactions, water and wastewater treatment, and agricultural activities. This research was conducted, in a completely randomized design, with the aim of investigating the effect of nickel ferrite and magnetite nanoparticles on wheat germination and seedling growth as well as some soil characteristics. In the seed germination test, nickel ferrite and magnetite nanoparticles were added to Petri dishes containing 25 wheat seeds at 7 nanoparticle concentration levels of zero, 20, 50, 100, 250, 500 and 1000 mg/L, in 3 replicates. In addition, nickel ferrite and magnetite nanoparticles in 7 concentration levels of 0, 20, 50, 100, 250, 500 and 1000 mg/kg were added to the soil of the pots under wheat cultivation in 3 replications. Before harvesting, the height and greenness of the plant were measured. After 40 days of the growth period, plants were harvested and oven-dried to measure the dry weight, iron and nickel concentration, and magnetic susceptibility of shoots and roots. Magnetic susceptibility, available iron and nickel concentrations, basal respiration, and microbial biomass carbon were also measured in the soil samples after the plant harvest. The results showed that low concentrations of the nanoparticles (20 mg/kg of nickel ferrite and 20-50 mg/kg of magnetite) had no effect on the seed germination percentage; however, the higher nanoparticle concentrations significantly decreased the percentages of seed germination. Moreover, seed germination significantly decreased by nanoparticle concentrations higher than 20 mg/kg and completely prevented by 500 and 1000 mg/kg of these nanoparticles. Increasing trends of plant shoot height and greenness index were measured at concentrations up to 250 mg/kg of nickel ferrite and 500 mg/kg of magnetite nanoparticles, but higher concentrations caused these parameters to be significantly decreased. In the presence of 50 mg/kg of nickel ferrite and 100 mg/kg of magnetite, the highest plant shoot and root dry weights were observed. The dry weight of shoots significantly reduced in nickel ferrite concentrations higher than 500 mg/kg. In addition, the dry weights of shoots and roots were significantly decreased by magnetite nanoparticles at concentration of 1000 mg/kg. Increased concentrations of nickel and iron in plant shoots and roots were observed with an increase i n the concentration of nickel ferrite and magnetite nanoparticles in the soil. In addition, by increasing the concentration of nickel ferrite and magnetite nanoparticles in soil, the available iron and nickel concentrations in soil, soil magnetic susceptibility, soil basic respiration, soil metabolic quotient increased, and soil microbial biomass carbon significantly decreased. Therefore, nickel ferrite and magnetite nanoparticles can affect the biological quality of the soil by affecting the microbial abundance and activity.
