It is imperative to eliminate bacteria present in water in order to avoid problems in healthy. Escherichia coli and Salmonella typhi bacteria are two common pollutants and they are developing resistance to some of the most used bactericide. Therefore new biocide materials are being tested. Thus, gold nanoparticles are proposed to inhibit the growth of these two microorganisms.

Managing waste generated by the food industry is a pressing environmental challenge, and traditional disposal methods such as landfilling or incineration are no longer viable solutions. However, by recovering and valorizing waste in wastewater treatment, we can address the waste management issue and the energy-intensive nature of conventional treatment methods with processes compatible with renewable energy technologies. In this work, avocado skin and seed are valorized for their application in removing Rhodamine B (RhB) dye. Avocado skin (ASk) and seed (ASe) were recovered and recycled separately to develop natural bioadsorbents. Biomaterials were characterized by XRD, XPS, ICP-MS, ATR-FTIR spectroscopy, TGA, N₂ adsorption/desorption, and SEM. The ASk and ASe bioadsorbents were employed to remove RhB at four experimental conditions: pH, RhB concentration, bioadsorbent concentration, and temperature. RhB removal was followed by UV–Vis spectroscopy. The results show that at pH 3, the highest percentages of dye removal are achieved, using ASk and ASe, with 88 and 92% removal, respectively. ASe bioadsorbent is more effective for removing RhB dye, reaching 92% after 4 h of contact with 2 g L⁻¹ of bioadsorbent and at 30 °C. Experimental results better fit a pseudo-second-order kinetic model and the Langmuir adsorption model, with maximum adsorption capacities of 13.1240 and 17.9998 mg g⁻¹ for ASk and ASe, respectively. The results show that natural bioadsorbents are suitable options for environmental remediation.

The mechanical stability of nanothin free-standing films made of melted polyethylene chains was predicted via molecular dynamics simulations in the range of 373.15–673.15 K. The predicted critical thickness, $t_c$, increased with the square of the temperature, T, with additional chains needed as T increased. From T = 373.15 K up to the thermal limit of stability for polyethylene, $t_c$ values were in the range of nanothin thicknesses (3.42–5.63 nm), which approximately corresponds to 44–55 chains per 100 nm². The density at the center of the layer and the interfacial properties studied (density profiles, interfacial thickness, and radius of gyration) showed independence from the film thickness at the same T. The polyethylene layer at its $t_c$ showed a lower melting T (<373.15 K) than bulk polyethylene.

Theoretical calculations of the reactivity of dibenzothiophene and its methyl, dimethyl, and trimethyl derivatives show that local reactivity descriptors reproduce their experimental desulfurization reactivity trend if the first desulfurization step involves directly the sulfur atom, which only occurs if the sulfur atom is blocked at most by one methyl group. In the series of molecules{4,7-dimethyldibenzothiophene,x,4,7-trimethyldibenzothiophene (x=1,2,3)}, the most reactive molecule is 2,4,7-trimethyldibenzothiophene, and local descriptors show that the reactivity is linked to the activity of the sulfur atom, which is higher in 2,4,7-trimethyldibenzothiophene due to the position of the third methyl substitute, located in theparaposition with respect to the carbon bonded to the sulfur atom. The electrostatic potential of 2,4,7-trimethyldibenzothiophene shows one effective adsorption site, while 1,4,7-trimethyldibenzothiophene and 3,4,7-trimethyldibenzothiophene have more sites, contributing to the higher reactivity of 2,4,7-trimethyldibenzothiophene. The index of reactivity of other descriptors was evaluated and the effect of the position of the methyl substituents on adsorption parameters, as the dipole moment and the atomic charges were also studied.