Effect of Biochar on Chemical Behavior and Radish Plant Uptake of Heavy Metals Grown in ‎Polluted Soils

Abstract

In this research, we studied the effect of sugarcane bagasse biochar (SCBB) on the chemical behavior of Zn, Ni, Cr, and Cu through speciation experiment in two contaminated soils from Alsharqia governorate soil A, and from Burg El-Arab (Alexandria Governorate) as soil B. In addition to, investigate bioavailability of these metals in soil after soil treatment with different rates of biochar (0.5, 1, and 2%) via pot experiment using radish plant (Raphanus sativus) as a bio-indicator. The results showed that exchangeable, carbonate and oxides-bound fractions decreased with increase biochar dosage. However, the residual and organic fractions increased. Bioavailability of Zn, Ni, Cr, and Cu decrease with increasing biochar application rate. Thus, the heavy metals concentrations in shoot and root decreased with increasing biochar dosage., for example in soil A when biochar dosage was 1% the percentage decrease of Zn, Cu, Ni, and Cr in shoot was 8.63, 6.25, 47.15, and 35.02% respectively. It can be suggested that high surface area and surface functional groups of biochar played an important role in fixation and stabilization of heavy metals in the forms of organic and residual fractions in soils.