Effect of activated carbon produced from biochar on removal of 2, 4-dichlorophenoxy acetic acid from aqueous solutions

Abstract

The toxicity of pesticides and their degradation products is making these chemical substances a potential hazard by contaminating our environment. Therefore, the removal of pesticides from water is one of the major environmental concerns these days. 2,4-Dichlorophenoxy acetic acid (2,4-D) belonging to the herbicide group, which is among the numerous pesticides used today, is widely used to control weeds due to its low cost and good selectivity. In order to offer an alternative to this environmental problem, the effect of activated carbon obtained by chemical activation from pyrolysis biochar on 2,4-dichlorophenoxy acetic acid removal from aqueous solutions has been investigated. The adsorption mechanism is explained by analyzing the effect of adsorption parameters. It is determined that the equilibrium data are suitable for Langmuir isotherm model among the applied isotherm models and the monolayer adsorption capacity is 344.83 mg g-1 at 318 K. The adsorption kinetics data of 2,4-D on activated carbon is better defined by the pseudo-second-order model. Thermodynamic calculations reveal that the adsorption process is spontaneous and endothermic. The activated carbon obtained from biochar has been observed to have a high adsorption capacity compared to adsorbent materials obtained from many other raw materials for the removal of 2,4-Dichlorophenoxy acetic acid.