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Cr-pillared interlayered clays (Cr-PILCs) have been prepared from natural calcium bentonite originating from a Romanian deposit and the effect of some parameters on the chemical and textural properties have been investigated. The crude bentonite and the derived materials were characterized by nitrogen adsorption-desorption technique, X-ray diffraction, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and transmission electron microscopy. The specific surface area values, the pore size distribution, morphological characteristics and the basal spacing of the Cr-PILCs are strongly affected by the process parameters. The influence of three relevant factors (metal/clay ratio, calcination temperature and calcination duration) on the specific surface areas of the Romanian Cr-PILCs was investigated using a 3 3 factorial design methodology. The optimum conditions to obtain CrPILCs with a specific surface area of 183 m 2 /g (more than four times higher than the raw material) were as follows: metal/clay ratio of 10 mmols/g, calcination temperature 300°C and calcination duration 60 min. The model developed in this paper predicts very well the experimental results. Due to the high porosity and adsorption properties, the prepared Cr-PILCs have great potential in remediation of industrial liquid effluents.

In this work, the advanced decomposition of organic dyestuffs used in food and textile industry, such as Malachite Green (MG), was investigated in the presence of a cationic catalyst montmorillonite (P1-PILCs) prepared by ion-exchange method. The obtained material was characterized by BET, FTIR and XRD. The effects of different variables such as: catalyst dose, catalyst/ozone dose, ozonation time and the pH on the mineralization of the synthetic dye were studied and optimal experimental conditions were ascertained. Compared with simple ozonation, the introduction of the catalyst greatly reduces the duration of the process to reach over 95% yield from 110 minutes to some seconds.

This paper presents the preparation of white bread with different hen eggshell powder additions. The aim of this paper is to resolve at least two important aspects: the waste recovery from food industry and fortification of white bread with minerals (calcium). The addition of eggshell powder to the white bread preparation was up to 2% and an increase in bread quality was on elasticity and humidity starting with 0.5% eggshell powder addition. Bread aging occurred 10 to 12 h after its baking. After 24 h, all physico-chemical properties of bread crust and crumb in the case of fortified bread with calcium had a positive effect.

Three synthons: methylene, nitrene and carbon monoxide form aziridinone in the presence of molecular nitrogen at low temperatures. This one, in contact with the same three synthons could form the precursors of the first proteinogenic amino acids. This paper is a theoretical, thermodynamically and reactivity study concerning the formation of the three previously named amino acids at low temperature conditions. The key intermediates are identified in the formation of the three amino acids: aziridinone, aziridinonil and methyl-aziridinonil radicals. The quantitative results, enthalpies of formation, reaction enthalpies and free energies were taken from quantum mechanical calculations acquired by density functional method (DFT): B88-LYP.

A facile, ecofriendly, and cost-effective method was developed to prepare a microporous material based on natural chemically modified bentonite with silver ions (BN-Ag0). This material presents a good catalytic activity against Malachite Green (MG) dye and bacteriostatic activity against a newly isolated bacterium from sewage sludge named hereafter “ISO SS” and Escherichia coli (E. coli). BN-Ag0 was characterized by the following methods: energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET), Fourier-transform infrared (FTIR) spectroscopy, temperature programmed desorption (TPD) and X-ray Diffraction (XRD). The new bacterium ISO SS, was isolated using the technique of isolating a pure culture of anaerobically stabilized sludge. A mandatory characterization of ISO SS isolated strains from anaerobic stabilized sludge was performed in the process of identifying bacterial species. The cationic clay-based nanomaterial showed appreciable antibacterial activity against ISO SS, a Gram-negative bacterium. It also showed good activity against E. coli bacteria. As a catalyst in the catalytic ozonation of MG dye, BN-Ag0 significantly improves the oxidation time of the dye, due to its good adsorption and catalytic properties. The catalytic and antibacterial activities of the natural bentonite (BN) and of BN-Ag0 were examined using performant characterization techniques. The lifetime of the BN-Ag0 catalyst was also evaluated. Results obtained are expected to provide valuable findings for the preparation of a good microporous material with multiple functionalities.

<p>Romanian calcium bentonite was modified by copper(II) ion-exchange, by varying the copper precursors (chloride, sulphate) and synthesis parameters (pH, temperature, time). The quantification of the Cu(II) ions was carried out by atomic absorption spectrophotometer. The modified bentonites were characterized by textural analysis (specific surface area by the Brunauer-Emmett-Teller method (BET) and by nitrogen adsorption/desorption isotherm), structural composition (X-ray diffraction (XRD)) and morphological analysis (scanning electron microscopy (SEM)). Analysis of the nitrogen adsorption/desorption isotherm shows that ion exchanged bentonites, not only contain mesopores, but micropores in larger quantities too. The values of the specific surface area increased by about 20 m²/g compared with raw bentonite, but the interlamellar distance values do not vary substantially. Scanning electron micrographs were acquired to demonstrate changes in the texture of the clay before and after ion exchange.</p>

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