Investigation the isotherm and kinetics of adsorption mechanism of herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on corn cob biochar

Abstract

The aim of this work was to study the isotherm and kinetics of adsorption mechanism of the herbicide 2,4-D on corn cob biochar in aqueous solution. Corn cob biochar was synthesized at 600 °C for 4 h, then, it was washed by HF acid modification. The characteristics of the biochar were considered including the point of zero charge, surface morphology, surface area, and functional groups. The specific surface area of biochar was 298.01 m2.g−1. Solution pH at 2.0 had the greatest removal efficiency for 2,4-D. The experimental adsorption data fitted with the Pseudo-second-order and Langmuir isotherm models. The chemical adsorption and pore-filling are the main interactions of 2,4-D and corn cob biochar. However, H-bonding is the most important interaction of chemical adsorption. Corn cob biochar is a very useful material for 2,4-D removal and pesticide pollutants, they can be further applied in the wastewater treatment plants as well as the water supply units.