Mesoporous Silica SBA-15 and SBA-15-NH2 as Potential Materials in the Adsorption of Glyphosate in Water Sources

Glyphosate is one of the most widely used herbicides in the agricultural sector. Its use worldwide is a cause for concern due to its harmful impact on water sources. Therefore, various techniques have been developed to remove this contaminant from water and rainwater. This research aims to produce SBA-15, whose name originated from the University of California, Santa Barbara (SBA), while the number 15 refers to the sample number, resulting in the material (SBA-15), which is a mesoporous silica made of silicon dioxide, an activated mesoporous silica, useful in adsorption processes thanks to its high porosity. Its mesoporous network is suitable for enzyme immobilization, making it one of the most widely used materials for contaminant adsorption. In this research, approximately 10.2 mg/g of glyphosate was removed at concentrations between 0 and 250 mg/L, and about 7.8 mg/g was removed using the activated carbon sample; this allows us to infer that two different samples are being compared. The contaminant was adsorbed with SBA-15, with the maximum adsorption rate achieved in water at a concentration of 250 mg/L. However, when SBA-15 is combined with NH2, the removal rate is even higher, reaching approximately 15.0 mg/g of contaminant removal. In both cases, a favorable fit greater than 0.99 is obtained using the Freundlich model. This research is significant due to the large number of water sources contaminated with this hazardous herbicide and, therefore, contributes to the UN Sustainable Development Goals.