The aim of this study is based on natural clay as an adsorbent in the elimination of polyphenols from olive mill wastewater (OMW). This clay was analyzed using XRD, SEM/EDX, FTIR, surface area measurement (BET method), thermal analysis (TGA/DTA), and X-ray fluorescence (XRF) and then used in adsorption experiments. The results reveal that the best quantity of adsorption of polyphenols is 161 mg/g at the temperature of 25°C, but they decrease at 35°C and 45°C. A great agreement with pseudo-second-order and Freundlich model is represented by kinetic and isotherms models, and several parameters such as ΔG⁰, ΔS⁰, and ΔH⁰ were determined using the thermodynamic function relationship.

The self-condensation reaction of acetone, producing diacetone alcohol (DAA), is of great industrial importance. It was used to study the catalytic activity of Mg-Al catalysts synthesized by the coprecipitation method. For this purpose, we synthesized Mg-Al based hydrotalcite with a molar ratio of 3, obtained either after conventional heating or after microwave irradiation with of 100W for three minutes. Structural and chemical properties of the obtained catalysts were characterized, using different techniques: X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), scanning electron microscope (SEM), equipped with energy dispersive X-ray (EDX), and specific surface area of the catalysts were determined by the methylene blue (MB) adsorption method. Also, these catalysts were tested in the self-condensation reaction of acetone at 273K in the liquid phase without solvent, a reaction which requires very high catalytic activity. The microwave treatment improves the catalyst activity, and the conversion of acetone to diacetone alcohol increases from 13.2 to 18.3 after 8h of reaction. Moreover, the microwave-treated hydrotalcite catalyst, calcined at 723K and rehydrated under a flow of N₂, is the most active and gives conversion of acetone of 52 under the same reaction conditions.

The present work aims to study the affinity of a component of the thyme essential oil “thymol” to natural Moroccan clay “Rhassoul” using the adsorption technique. The physicochemical characterizations of the purified and modified clay were carried out by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), DTA/TGA, and SEM-EDX. Thymol adsorption tests on the purified Rhassoul (Rh-P) and the modified one by CTAB (Rh-CTAB) were followed by UV-visible spectroscopy. They show that the adsorption isotherms can be described by the Freundlich model and that the kinetics of adsorption is in accordance with the pseudo-second-order model for the two clays. Adsorption capacities obtained were of the order of 6 mg/g for the purified Rhassoul and 16 mg/g for the modified Rhassoul by cetyltrimethylammonium bromide (CTAB). These values show that the modified Rhassoul has a better adsorption capacity compared to the purified Rhassoul.

Hammada scoparia (Pomel) is a powerful plant with important biological properties. In this study, we report on the green synthesis of silver-doped nickel and copper nanoparticles (NPs) in the presence of H. scoparia leaf extract using a self-propagating sol–gel autocombustion process. The synthesized NiO, CuO, Ag-NiO, and Ag-CuO NPs were characterized with Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Afterward, they were tested for their antimicrobial activity as well as their potential to remove dyes from aqueous solutions using adsorption processes for malachite green (MG) and photocatalytic degradation for methylene blue (MB). Our results showed that the mass of the adsorbent had a significant effect on the adsorption rate, which increased to reach a maximum value of 98%. The Ag-CuO NP showed the best final conversion of MB (97.95%) compared to NiO, CuO, and Ag-NiO. In addition, we noted that the NPs doped with silver had the best performance in the removal of dyes. These results indicated that the photocatalytic performance was significantly improved after the addition of silver. Moreover, the antimicrobial activity showed that the studied NPs had moderate activity against the tested bacteria and a weak activity or were ineffective against Candida albicans. Therefore, the green synthesis of NPs from H. scoparia leaf extract is considered a sustainable alternative to removing dyes from aqueous solutions. However, further investigation should be performed on the other dyes to understand the overall effectiveness of these NPs.