Spectroscopic analyses to study the effect of biochar and compost on dry mass of canola and heavy metal immobilization in soil

Abstract

This research was conducted to use spectroscopic analysis to evaluate the effect of biochar and compost application on heavy metal immobilization during the canola plants grown in the contaminated soil using X-Ray Diffraction (XRD), Energy Dispersive spectroscopy by X-rays (EDX) and Fourier Transmission Infrared Spectroscopy (FTIR). The results showed that the cadmium (Cd) and lead (Pb) concentrations in the root and shoot of canola plants significantly decreased with the addition of rice straw compost (RC) and biochar (RB) to contaminated soil. The use of spectroscopic analysis observed the precipitation, inner-sphere complex reaction, and electrostatic attraction are the dominating mechanisms for heavy metals immobilization with organic amendments. Our results indicate that the rice straw biochar and compost can immobilize heavy metals and improve dry weight of canola plants. Moreover, the spectroscopic analysis is a simple method and can be effective to understand the mechanism of heavy metals immobilization.