Incorporation of biochar and nanomaterials to assist remediation of heavy metals in soil using plant species

Remediation of heavy metal-contaminated soils brings a techno-economical challenge for researchers and decision makers. The main purpose of this research is to study the co-application of nanoscale zerovalent iron (nZVI) and biochar (BC) to support remediation of cadmium contaminated soil using plant species. Plant seeds were exposed to various concentrations of nZVI and BC in the heavy metal-contaminated soil. Zero-valent iron nanoparticles were prepared using borohydride reduction method. Fresh urban yard trimmings were used to prepare BC at high pyrolytic temperature. Co-application of nZVI and BC enhanced plant germination and biomass establishment in contaminated soil. Concentration of cadmium in plant tissues increased with nZVI concentration, while application of BC enhanced immobilization of Cd in the soil. Inhibitory effect of the applied doses of nZVI on contaminant uptake by plants was not observed in this research. Integrated use of nZVI and BC significantly increased accumulation capacity of T. repens for cadmium with the greatest accumulation capacity of 1077.9 μg per pot achieved in “300 mg/kg nZVI+2.5% BC” treatment (P<0.05). Moreover, co-application of nZVI and BC positively affected chlorophyll content of the plant grown in contaminated soil. Combined use of nZVI and BC could promisingly assist phytoremediation of heavy metals in soils and would have great application prospect in dealing with soil remediation in the future