Reduction of soil heavy metal bioavailability by nanoparticles and cellulosic wastes improved the biomass of tree seedlings

Abstract

The purpose of this study was to use zero‐valent iron nanoparticles (nZVI) and cellulosic wastes to reduce bioavailability of lead (Pb) and cadmium (Cd), and to establish Persian maple seedlings (Acer velutinum Bioss.) in contaminated soil. One‐year‐old seedlings were planted in pots filled with unpolluted soil. Lead [Pb(NO3)2] and Cd [Cd(NO3)2] were added with concentrations of 0 (Control), 100 (Pb100), 200 (Pb200), and 300 (Pb300) mg kg−1 and 10 (Cd10), 20 (Cd20), and 30 (Cd30) mg kg−1. Cellulosic wastes were mixed with soil at the same time of planting [four levels: 0, 10 (W1), 20 (W2), 30 (W3) g 100 g−1 soil]. The nZVI was prepared by reducing Fe3+ to Fe0 and injected to pots [four levels: 0, 1 (N1), 2 (N2), and 3 (N3) mg kg−1]. Height, diameter, biomass, tolerance index of seedlings, bioavailability of heavy metals in soil, and removal efficiency of amendments were measured. The highest values of seedling characteristics were observed in N3. The highest removal efficiency of Pb (Pb100: 81.95%, Pb200: 75.5%, Pb300: 69.9%) and Cd (Cd10: 92%, Cd20: 73.7%, Cd30: 68.5%) was also observed in N3. The use of nZVI and cellulosic waste could be a proper approach for seedling establishment in forests contaminated with heavy metals.

Using nano-scale Fe0 particles and organic waste to improve the nutritional status of tree seedlings growing in heavy metal-contaminated soil

“…In this study the bioavailabile concentrations of Pb and Cd were provided as a function of initial concentration of heavy metals and soil amendments level. The addition of CW and Fe 0 -NPs caused a significant decrease in the bioavailability of Pb and Cd in the soil, which is consistent with the findings of Tafazoli et al (2017), Danila et al (2018), andXu et al (2019). The addition of organic matters can affect the availability of heavy metals in the soil through the formation of chelate and complexes of organic materials.…”

“…Cell division may be inhibited by the presence of Cd in plants, and the synthesis of RNA can be changed (Liu et al 1994). Various studies reported that the seedling growth of different species, as well as maple seedling, was affected by Pb and Cd (Tafazoli et al 2017, Marzilli et al 2018. Other reasons for the decreasing trend in the seedling biomass resulting from high concentrations of heavy metals in the soil might be due to the disturbance or prevention of the nutrient uptake by plants and photosynthetic activities (Borghi et al 2007).…”

“…The addition of organic matters can affect the availability of heavy metals in the soil through the formation of chelate and complexes of organic materials. Therefore, the application of organic matters and related amendments such as CW immobilizes heavy metals in contaminated soils (Sampanpanish & Pongpaladisai 2011, Tafazoli et al 2017. Negative-charged functional groups (e.g., carboxylic acids, phenolic and alcoholic hydroxyls) could form complexes with Pb and Cd to decrease their availability (Weil & Brady 2016.…”

“…Previous studies on the effect of soil amendments have focused on the seedling biomass and bioavailable concentration of Pb and Cd in the soil (Tafazoli et al 2017). However, examinations of the effect of soil amendments in polluted soil on the concentration of heavy metals and macro-elements in forest seedlings' organs are still scarce.…”

Effect of Metal Oxide Nanoparticles on the Chemical Speciation of Heavy Metals and Micronutrient Bioavailability in Paddy Soil

“…For example, Shrestha et al (2015) found that multiwalled carbon nanotubes (MWCNTs) significantly reduced the toxicity and bioavailability of polycyclic aromatic hydrocarbons (PAHs) in the soil microbial community, and the effects were dependent on the soil organic matter content [11]. Zero-valent iron nanoparticles (nZVI), often used in water and soil pollution remediation, could effectively reduce contaminants' bioavailability [12,13]. Graphene oxide (GO) could promote the transformation of arsenic (As) from As(V) to high-toxicity As(III) in soil, and significantly influence the morphological and biochemical characteristics of rice [14].…”