One of the challenges of our time is replacing the existing fossil fuel-based economy with a green one in the framework of developing a sustainable society. The biological synthesis of nanoparticles from plant extracts is currently under study for developing environmentally compatible nanoparticle synthesis and avoiding adverse effects. The environmental impacts of emissions, energy requirements, and energy losses are calculated to comparatively evaluate the effects of the traditional process, in addition to any new one, in obtaining TiO₂ nanoparticles from the life cycle point of view. The two methods are syntheses via green chemistry (using an aqueous extract of Cymbopogon citratus) and via the chloride route, which are some of the most used methods for the synthesis of TiO₂ nanoparticles owing to them having the most advanced production processes. The life cycle analysis was carried out using OpenLCA software, which showed that the production of chemically synthesized TiO₂ contributes to greenhouse gas emissions and respiratory effects caused by inorganic substances. On the other hand, green synthesis contributes to reductions in toxicity and greenhouse gas emissions.

In this study, the use of Polyvinylchloride (PVC) and High Density Polystyrene (HDPS) was demonstrated as an alternative for the adsorption of Malathion. Adsorption kinetics and isotherms were used to compare three different adsorbent materials: PVC, HDPS, and activated carbon. The adsorption capacity of PVC was three times higher than activated carbon, and a theoretical value of 96.15 mg of Malathion could be adsorbed when using only 1 g of PVC. A pseudo first-order rate constant of 1.98 (1/h) was achieved according to Lagergren kinetic model. The adsorption rate and capacity values obtained in the present study are very promising since with very little adsorbent material it is possible to obtain high removal efficiencies. Phosphorous and sulfur elements were identified through Energy Dispersive X-ray (EDX) analysis and evidenced the malathion adsorption on PVC. The characteristic spectrum of malathion was identified by the Fourier Transform Infrared (FTIR) Spectroscopy analysis. The Thermogravimetric and Differential Thermal Analysis (TG/DTA) suggested that the adsorption of malathion on the surface of the polymers was mainly determined by hydrogen bonds.

Currently there is a growing concern about the presence of emerging contaminants (EC) in water bodies and their potential ecotoxicological effects. Pharmaceuticals, a type of EC, are widely distributed in the environment and their main entry is through wastewater from treatment plants, since these systems are not designed to remove EC. In this sense, the photo-Fenton process, an advanced oxidation process, has proven to be highly efficient in degrading new potentially harmful contaminants. However, this process is affected by multiple factors, which makes it necessary to implement a methodological strategy to optimize the photo-Fenton process. Within these, the Taguchi method provides robust and low-cost solutions with the least number of experiments, providing knowledge of the contribution of each of the factors studied to the response variable. In addition to the above, the Taguchi method can be coupled to a Grey relational analysis (Grey–Taguchi method), which will allow the optimization of more than one response variable at the same time. This paper discusses the parameters that affect the photo-Fenton process and the application of designs of experiments to optimize the process.

Groundwater is an important source of fresh water in the world. However, the excessive extraction and increasing pollution represent a major challenge for water sustainability in Mexico. Nowadays, since water quality changes in aquifers are not noticeable, aquifer monitoring and assessment are imperious. In this study, the water quality of the Cuernavaca aquifer was evaluated using a database of 23 parameters in 4 sampling points from 2012 to 2019. The spatial behavior of water quality variables was described by using interpolation. The temporal evaluation of groundwater quality was carried out through time series. Water quality indices (WQI) were obtained in this aquifer and the WQI values suggest that the groundwater could be considered as good quality for potable use and of medium-high quality for irrigation. The chemical characteristics of the groundwater were also evaluated using Gibb, Piper, and Schoeller diagrams. Finally, with a total of 34 samples of each parameter in each sampling site, a multivariate statistical analysis was performed using a Pearson correlation and hierarchical cluster analysis. This analysis showed a correlation between hydrochemical features and groundwater quality parameters, where nitrates presented the highest number of significant correlations with other parameters. These results may be useful for the authorities to adopt planning methods to improve the sustainable development of the aquifer.

A functionalised coating for mild steel corrosion protection was prepared in this study. A composite material SBA-15 (silicon oxide) was used as a mild steel corrosion inhibitor. The porous matrix (SBA-15) was loaded with fluconazole (F), as an inhibitor container. A sol–gel technique was used to synthesise SBA-15; and the active molecule (F) was extracted from an outdated medication using methanol as solvent. The final composite was obtained by SO₂ dispersion in a methanol-F solution. The composite material was dispersed in a nitrocellulose resin, and it was characterised by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscope (TEM), Fourier Transform Infrared Spectrometry (FTIR), and physical adsorption of Nitrogen. Coatings were electrochemically evaluated by electrochemical impedance spectroscopy (EIS) tests, using a chloride/sulphate solution prepared from NaCl and (NH₄)₂SO₄. The results demonstrated the effectiveness of the inhibitor delivery system and the consequent protection of metal against the corrosion process.