Decontamination of water contaminated by the herbicide glyphosate through adsorption technology: a critical review

Abstract

One of the biggest problems facing today's society is the rampant use of herbicides, as agricultural overproduction increasingly relies on these chemicals. Despite having a targeted application, their release into soil particles and water resources is inevitable, leading to damage at environmental and social levels. Therefore, adsorption technology presents itself as an alternative to decontaminating wastewater, presenting a high advantage in the removal and cost-benefit of the process. This study provides a qualitative exploratory analysis, where the understanding of the topic is achieved based on a thorough bibliographical survey focused on the removal of glyphosate using different adsorbent materials. Work related to glyphosate adsorption analyzes several parameters such as pH, adsorbent dosage and adsorbate concentration, kinetic time, and temperature effect. It was observed that when the herbicide concentration was increased, the adsorption capacity also increased, whereas removal showed the opposite behavior, decreasing with increasing concentration. The ideal pH value depends largely on the characteristics of the adsorbent such as surface area, and functional groups present on the surface, among others. The kinetic studies showed a better fit to the Pseudo-second order model, while the adsorption equilibrium studies showed a better fit to the Freundlich and Langmuir model. Therefore, current literature shows that several materials can be used as alternative sources of adsorbents for the remediation of glyphosate present in water