Synthesis of clay-biochar composite for glyphosate removal from aqueous solution

In this work, Clay-Biochar composite was synthesized from local Clay and local cotton wood, and applied for removal of glyphosate from aqueous solutions by adsorption. The Clay, Biochar and Clay-Biochar composite were characterized using X-ray diffraction, scanning electron microscope, fourier transform infrared spectroscopy, and thermal analysis. The adsorption studies of glyphosate were investigated by batch process at laboratory temperature. Adsorption experiments showed that the composite exhibited much better adsorption capability than both Clay and Biochar. The adsorption kinetics of glyphosate obeyed pseudo-second-order model according to their high coefficient R² = 0.996, 0.995, 0.999 for Clay, Biochar and Clay-Biochar composite, respectively. The equilibrium adsorption data was best described by Langmuir model with R² values of 0.937, 0.989, and 0.993 and Temkin model with R² values of 0.982, 0.909, and 0.983, each for Clay, Biochar and Clay-Biochar respectively. Therefore, Clay-Biochar composite could be applied in the remediation of glyphosate in contaminated aqueous media.