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Abstract: Application of microemulsion modified raw date pits as an inexpensive solid extractant for removing methylene blue (MB), copper ion (Cu2+) and cadmium ion (Cd2+) has been presented. The results summarised herein are also part of an investigation conducted to evaluate the adsorption capacity by taking into consideration the experimental parameters such as pH, particle size and initial solute concentration. The experimental data obtained from the adsorption isotherms studies were used to find pollutants distribution factors and modelled using both Langmuir and Freundlich equations. The modified adsorbent was more effective toward all pollutants with high removal capacities (50–350 mg/g) and with very large distribution values (9–235 L/g) which indicates the suitability of this new material for extraction organic and inorganic pollutants. After microemulsion modification, the FTIR scans of the samples show clear differences in the position and intensity the characteristics bands of the raw date pits (RDP). Three mechanisms of the MB, Cu2+ and Cd2+ adsorption onto μE-MDP are possible: (i) adsorption by an electrostatic force of the anionic head group of the surfactant and the positive charge of the dye (MB+) or the metal ions (Cu2+ or Cd2+), (ii) adsorption by tail groups of the surfactant and the hydrophobic character of the MB molecules. The MB is a basic dye and has basic characteristics and therefore is expected to interact strongly with the anionic head groups of the surfactants (RCOO–). In the contrary, the Cu2+ and Cd2+ ions are not expected to interact by the tail groups of the surfactant where the ionic radii of these ions may explain the differences between Cu2+ (0.72 Å) and Cd2+ (0.99 Å) adsorption capacities and (iii) filling the channel (pores) of the RDP by dissolving in the microemulsion micelles. [Copyright &y& Elsevier]

Abstract: As a result of the changes that occur during their use, used engine oils tend to differ in chemical and physical composition from a virgin oil. In general recycled oils have: much higher water and sediment levels than virgin oil; relatively higher concentrations of organic compounds (oxidation products); and relatively higher levels of metals such as Fe, Cd, Cr, Pb, etc. Therefore, the aim of this work was to investigate, assess and to observe, by means of the physical and the chemical properties of the oils, atomic absorption (AA), inductive couple plasma (ICP) and Fourier transform infrared (FTIR) analyses the extent of the differences occurring between the virgin and recycled oil. In important part of this work was also the development of analytical techniques based on the use of FTIR spectroscopy; in relation to the rapid analysis of lubricants; in particular for the differentiation of virgin and recycled oil. The results obtained were expected to be useful for differentiation purposes, providing information on whether the metal concentrations and oxidation products could be an appropriate feature for differentiating a particular oil sample from the others. This work is categorized into a two-step procedure. Firstly, an evaluation of a typical FTIR spectrum of an engine oil sample (mono- and multigrade) is presented. The broad feature centered at 1716cm−1 is due to the presence of carbonyl containing degradation products of oil. A band observed at 1732, 1169, 1154 and 1270cm−1 assigned to the polymethacrylate stretching vibrations, allows the determination of viscosity modifier and pour point depressant additives. The observed differences in the specific spectral bands (1732, 1169, 1154 and 1270 and 1716cm−1) are investigated and discussed. Secondly, an analytical technique for the measurement of the levels of the wear metals is also applied. [Copyright &y& Elsevier]