EFFECT OF BIOCHAR ON CADMIUM, NICKEL AND LEAD UPTAKE AND TRANSLOCATION IN MAIZE IRRIGATED WITH HEAVY METAL CONTAMINATED WATER

Abstract

This study was conducted to investigate the effect of biochar on bioavailability reduction of cadmium (Cd +2 ), nickel (Ni +2 ), and lead (Pb +2 ) and its subsequent effects on soil properties and maize plant growth in a soil which was irrigated by contaminated water with above heavy metals. Twelve different biochar were prepared under two temperatures of 500 C and 700 C by using six biomass including residuals of wheat (WB), chickpea (CB), maize (MB), reed (RB), olive (OB) and sugarbeet (SB). Physicochemical properties of biochar including product percentage, percentage volatile matter, ash, pH, electrical conductivity (EC), cation exchange capacity (CEC), specific surface, and organic carbon (OC) were studied as well. Subsequently, the effects of 3 biochar selected under 700 C (MB700, RB700, WB700) at the levels of 0%, 2%, and 4% were employed for pot experiments. The results showed that higher level of temperature significantly (P < 0.05) increased pH, EC, ash percentage, specific surface area, and OC content of soil however Cd, Ni, and both shoot and root dry biomass decreased. This study results indicated that high application of biochar significantly decreased leaf area, and also shoot and root biomass.