Remediation of cadmium in soil by biochar-supported iron phosphate nanoparticles

Effects of biochar on heavy metals migration and fractions changes with different soil types in column experiments

“…The distribution of different Cd fractions in the deep layer was changed. The reducible Cd fractions (22.2%) were transformed into other forms, probably because the leaching also brought the change of soluble organic matter from biochar and changed the Cd fraction (Qiao et al 2017). The 1% and 5% branch and leaf biochar treatments decreased the ratio of exchangeable Cd fractions in the surface layer by 4.5% and 10.7%, and increased reducible Cd fractions by 4.8% and 8.7% compared with the control, respectively.…”

“…The ratio of oxidizable and reducible Pb fractions in the 4 to 20 cm soil was increased; the soluble organic matter in leaching solution was responsible for this. Qiao et al (2017) found that the Chinese herb medicine residue biochar immobilizes 81.3% Cd in contaminated soil during 28 days incubation, which shifted Cd ion from exchangeable fraction (i.e., bioavailable fraction, which was easy uptake with root.) into residual fraction and organic bound phases (i.e., stable fraction, which was difficult uptake with root.).…”

“…In addition, amending soil with biochar has been paid more attention due to its great effects on soil quality and crop productivity improvement (Ahmad et al 2014;Ling et al 2017;Wu et al 2017). The improved biochar (10%, w:v) effectively immobilizes 81.3% Cd after 28 days culture experiment, and the bioavailable Cd is reduced 80.0%, and the cabbage mustard belowground and aboveground parts showed decreased Cd uptake by 44.8% and 70.2%, respectively, which promotes cabbage mustard growth (Qiao et al 2017). The 3% (w:w) biochar reduced porewater Cd in rhizosphere, resulting in 68% and 49% reduction in the root and grain Cd, which is efficient on Cd mobility in rice rhizosphere and transferring from soil (Yin et al 2017).…”

Effect of engineered nanoparticles on soil biota: Do they improve the soil quality and crop production or jeopardize them?

“…The use and evaluation of ENP for soil decontamination have been reported and widely discussed, in which nanoscale zero-valent iron (nZVI) is one of the most studied materials for environmental sanitation in the last 20 years (Zhao et al, 2016). Soil cleaning has arisen for decontamination by halogenated compounds, nitrates, phosphates, aromatic hydrocarbons and heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), etc.…”

“…Soil cleaning has arisen for decontamination by halogenated compounds, nitrates, phosphates, aromatic hydrocarbons and heavy metals such as cadmium (Cd), chromium (Cr), copper (Cu), zinc (Zn), nickel (Ni), etc. (Feizi, Jalali, & Renella, 2018;Paomephan et al, 2018;Qiao et al, 2017). However, there is a lack of evidence of ENP in the movement through the pores of the soil, in their adsorption to mineral particles (Cecchin, Reddy, Thom, Tessaro, & Schnaid, 2017), and especially regarding the reduction of soil microbial communities (Hou et al, 2018).…”