Numerous investigations have been conducted to address 2,4-D removal from water via adsorption approach. The present review offers insights into the underlying mechanisms, pinpoint gaps in the knowledge of the process, and offer a perspective for forthcoming inquiries. Notably, the highest adsorption capacity for 2,4-D reaches 556 mg/g, attributed to a metal-organic framework (MOF) based on porous chromium-benzenedicarboxylate. 2,4-D interactions with most adsorbents are usually by electrostatic interactions, hydrogen bonds, van der Waals forces, and π–π interaction. Isotherm modelling for 2,4-D uptake reveals either Langmuir or Freundlich as best-fit depending on whether uptake is monolayer or multilayer. The pseudo-second order kinetic equation effectively modelled the kinetics of uptake, highlighting that the rate of adsorption is contingent upon both the quantity of active sites and the concentration of 2,4-D within the aqueous phase. The thermodynamics modelling reveals that its adsorptive uptake is always spontaneous. Over a wide range of eluents, 2,4-D can be desorbed from the adsorbents back into the aqueous phase and the adsorbents are mostly reusable for over 5 cycles. Future work could explore the economic analysis and scalability of adsorption processes for the removal of 2,4-D. © 2023 Elsevier Ltd
