5 - A comprehensive review of glyphosate adsorption with factors influencing mechanism: Kinetics, isotherms, thermodynamics study

Abstract

Glyphosate (N-[phosphonomethyl] glycine) pollution is mainly due to industrial drainage and unnecessary use for agricultural and residential weed control purposes, which in turn creates ecosystem and environmental toxins. There are very important research fields needed for decontamination in a sustainable way. In this chapter, we discuss an adsorption process of glyphosate from aqueous solution with influencing mechanisms, which are kinetics, isotherms, and thermodynamics. Reported results are depicted by consequence factors, namely pH, contact time, initial taken concentration, doses, etc. Adsorbents preparation and their characterization are elaborated, namely zero point charge (ZPC), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), etc. The review posits that glyphosate removal and comparisons between their adsorption capacity, removal percentage, and type of adsorbents are easily available. Outcome data have been described with kinetic models; basically, uses of pseudo-first order, pseudo-second order, intraparticle diffusion, and equilibrium studies for monolayer capacity have been achieved through Langmuir isotherm, which also gives an empirical relationship between glyphosate concentration and heterogeneous/homogeneous adsorbent surface. Present studies highlight plant-mediated adsorbents, nanomaterials, soils, and miscellaneous adsorbent materials, which are emphasized due to being lead nonpollutant, lower cost, and greener. A comparison of other related adsorbents, which do not use glyphosate adsorption, is not available in this study. However, the reviews surveyed more or less glyphosate adsorption papers and related papers of pesticides, supporting lead pesticide remediation.