Evaluation of a pilot system for removal of the herbicide 2,4-dichlorophenoxyacetic acid and absorbance determination after clarification and adsorption on granular activated carbon

Abstract The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) has been detected in water bodies worldwide, precluding their use for supply. Despite this, scientific studies assessing the behavior of herbicides treatment systems are scarce, which motivated this study on 2,4-D removal. removal and its relationship with absorbance were investigated using a pilot system comprising coagulation, sedimentation, filtration, granular activated carbon (GAC) adsorption, chlorinated disinfection. ranged from 15 to 64% after negative values 19% 5 16% chlorination, total rates 19 70%. Breakthrough curves showed an adsorption capacity 0.70 mg g−1 GAC C/C0 ratio 0.50 VTW/VGAC 3.598 breakthrough concentration 30 ± 3 μg L−1. positive correlation between (R2 = 0.78) column effluent indicated that can be used early prediction breakthrough. associated coagulation produced treated accordance criteria turbidity, apparent color, established by Minister's Office/Ministry Health — GM/MS Ordinance No. 888/2021, representing promising technological alternative systems.