Glyphosate [N-(phosphonomethyl)-glycine] is a herbicide with several commercial formulations that are used generally in agriculture for the control of various weeds. It is the most used pesticide in the world and comprises multiple constituents (coadjutants, salts, and others) that help to effectively reach the action’s mechanism in plants. Due to its extensive and inadequate use, this herbicide has been frequently detected in water, principally in surface and groundwater nearest to agricultural areas. Its presence in the aquatic environment poses chronic and remote hazards to human health and the environment. Therefore, it becomes necessary to develop treatment processes to remediate aquatic environments polluted with glyphosate, its metabolites, and/or coadjutants. This review is focused on conventional and non-conventional water treatment processes developed for water polluted with glyphosate herbicide; it describes the fundamental mechanism of water treatment processes and their applications are summarized. It addressed biological processes (bacterial and fungi degradation), physicochemical processes (adsorption, membrane filtration), advanced oxidation processes—AOPs (photocatalysis, electrochemical oxidation, photo-electrocatalysis, among others) and combined water treatment processes. Finally, the main operating parameters and the effectiveness of treatment processes are analyzed, ending with an analysis of the challenges in this field of research.

The present work describes and discusses some novel aqueous colloidal generation of Bi, (BiO)2CO3, and (BiO)4(OH)2CO3 nanoparticles (NPs) and their structural characterization. These Bi NPs are transformed into (BiO)2CO3 NPs by capturing atmospheric CO2 at room temperature. This transformation is highly dependent on pH, temperature, and the presence of halloysite nanotubes (HNTs) in the solution. When halloysite was present, small (7 nm) nanospheres were obtained. A substantial change in the relative intensity of the peaks in the X-ray patterns for (BiO)2CO3 was observed. In some cases, that change was due to water molecules within the (BiO)2CO3 powder. The crystallite sizes associated with the crystallographic planes parallel to the (040) plane were smaller than for the remaining planes. This difference was more appreciable for (BiO)2CO3 nanoplates and nanorods that have the ability to float on water. β-Bi2O3 NPs, suspended in water and exposed to the light from a xenon arc lamp for 16 h, produced a mixture of (BiO)4(OH)2CO3 and (BiO)2CO3. These β-Bi2O3 NPs are an interesting material to capture atmospheric CO2 dissolved in water, in comparison with the capture of CO2 dissolved in air, increasing the carbon dioxide amount trapped. Transmission electron microscopy (TEM) images revealed that the shape of the bismuth subcarbonate are mainly large nanoplates with rectangular shape (edge lengths vary from 280 to 400 nm).

En el desarrollo de este trabajo de investigación se han sintetizado y caracterizado nanocompositos en base de halloysita con nanopartículas de sulfuro de bismuto. La halloysita, es un filosilicato que se encuentra en forma de nanotubos de multicapas y constituye una alternativa de morfología similar a los nanotubos de carbono; sin embargo, posee características químicas distintas en la superficie externa e interna. La síntesis se llevó a cabo utilizando un método de impregnación de los precursores en nanotubos de halloysita para el posterior crecimiento de las nanopartículas in situ. La caracterización incluyó espectroscopias de absorción electrónica (UV-visible) y difracción de rayos X, en polvos. La morfología de los nanocompositos preparados se evidenció utilizando microscopía de barrido electrónico (SEM) y microscopía de transmisión electrónica(TEM); además se utilizó espectroscopia de energía dispersiva (EDS) para identificar elementos particulares y su distribución en la muestra. Los resultados indican que las nanopartículas de Bi2S3 (Bi2S3 NPs), de morfología esférica, se depositaron de manera uniforme sobre los nanotubos de halloysita (HNTs). Las partículas en el nanocomposito presentaron mayor diámetro que las partículas sintetizadas sin HNTs. Este cambio se evidencia en la reducción del ancho del pico en los patrones de difracción y en la disminución de valor de energía de la brecha energética. La formación del nanocomposito contribuyó a mantener las nanopartículas dispersas de manera homogénea sobre halloysita, evitando su aglomeración. Además, se evidenció el control de tamaño y morfología cuando se utiliza los nanotubos como soporte.