CASSAVA WASTE DERIVED BIOCHAR AS SOIL AMENDMENTS: EFFECTS ON KINETICS, EQUILIBRIUM AND THERMODYNAMICS OF ATRAZINE ADSORPTION

Converting waste into biochar (BC) is being considered as one of most potential waste disposal and resource recycling utilization options. And biochar has been recognized as an efficient adsorbent. In this study, adsorption behavior of atrazine on soils amended with biochars prepared from cassava waste at different temperatures (350 degrees C, 550 degrees C, 750 degrees C) was examined. Biochar was characterized via elemental analysis, surface area analyzer, FUR and scanning electron microscopy (SEM). The biochar pyrolyzed at higher temperatures more quickly reached equilibrium, and the pseudo-second-order model described sorption kinetics well with the coefficients R-2 above 0.991. The Langmuir and Freundlich model simulated the sorption isotherms well, and the isotherms of MS350 displayed relatively linear, while MS550 and MS750 followed a nonlinear isotherm. Furthermore, thermodynamic analysis demonstrated that the adsorption of atrazine in biochar-amended soil was an endothermic and spontaneous process, and the primary sorption process was physical sorption. Atrazine sorption was also favored in acidic solution and under higher temperature conditions. This study constitutes a basis for further research considering the waste recycle utilization and the application of biochar to remove organic contamination.