Glyphosate Removal from Water Using Biochar Based Coffee Husk Loaded Fe3O4

Abstract

Glyphosate is an herbicide that is usually used by farmers and is considered harmful to the environment in excess amounts. To address these issues, coffee-husk-biochar-loaded Fe3O4 (CHB- Fe3O4) was used as an adsorbent to remove glyphosate from water. CHB-Fe3O4 characteristics such as pHpzc, FTIR, and SEM were measured to understand the properties of this adsorbent. The best conditions for glyphosate removal by CHB-Fe3O4 were obtained at pH 2.0, where the adsorption capacity and percentage removal are 22.44 mg/g and 99.64%, respectively, after 4 h of adsorption. The Freundlich model provided the best fit for the adsorption isotherm, demonstrating multilayer sorption. The most effective model for characterizing the adsorption kinetics was the pseudo-second-order model with a chemical adsorption mechanism. The desorption studies found that the use of 0.1 M NaOH was the best concentration to effectively desorb glyphosate with a desorption percentage of 69.4%. This indicates that CHB- Fe3O4 is a feasible adsorbent for glyphosate removal from water.