Ryszard Cierpiszewski

Active and intelligent packaging food - research and development - a review.

Abstract Innovation in food and beverage packaging is mostly driven by consumer needs and demands influenced by changing global trends, such as increased life expectancy, and fewer organizations investing in food production and distribution. Food industry has seen great advances in the packaging sector since its inception in the 18th century with most active and intelligent innovations occurring during the past century. These advances have led to improved food quality and safety. Active and intelligent packaging is a new and exciting area of technology which received efficient contemporary consumer response. The aim of this review article was to present active and intelligent packaging currently existing on the market

Kinetic and equilibrium studies of the removal of cadmium ions from acidic chloride solutions by hydrophobic pyridinecarboxamide extractants.

Liquid-liquid extraction of cadmium(II) from acidic chloride solutions was carried out with alkyl derivatives of pyridinecarboxamide in toluene with addition of 2-ethylhexan-1-ol as modifier. Equilibrium as well as kinetic studies was performed. The kinetic studies of a Cd(II) extraction process were carried out with a Lewis cell having a constant interfacial area. Cadmium(II) concentration in the aqueous phases was determined by atomic absorption spectroscopy (Varian SPECTR AA800). The results of equilibrium experiments showed that cadmium(II) was quantitatively extracted with N,N-dihexylpyridine-3-carboxamide whereas the derivative N,N-dihexylpyridine-2-carboxamide was not able to transfer Cd(II) ions from the aqueous phase to the organic one. Thus, the kinetics of extraction and the initial extraction rate were examined only in the systems with N,N-dihexylpyridine-3-carboxamide. The obtained experimental data as well as the calculated values of mass transfer coefficients suggest that the investigated process of extraction of Cd(II) by means of pyridinecarboxamide as extractant occurs in the mixed diffusion-kinetic region. Moreover, the results of adsorption studies indicated that the extraction of Cd(II) with a hydrophobic extractant should be considered as an interfacial process.

Studies on the kinetics and equilibrium of the solvent extraction of chromium(III) from alkaline aqueous solutions of different composition in the system with Aliquat 336

The kinetics and equilibrium of Cr(III) extraction with Aliquat 336 from the alkaline aqueous solutions containing anions of various complexing abilities and solvating properties, as: nitrates, or perchlorates, or sulphates, were studied and interpreted. Stoichiometry of Cr(III) complexes formed in the organic phases was also discussed. It was found that under the same conditions the yield and the rate of Cr(III) extraction as well as values of mass transfer coefficient increase in the following order of anions: perchlorates<nitrates<sulphates. The equilibrium of extraction of Cr(III) in the systems with nitrates and/or perchlorates differs significantly from that one established for the extraction of Cr(III) from the alkaline aqueous solutions of sulphates. Experiments with the modified Lewis cell and analysis of the experimental data by mathematic models appeared that the studied extraction of Cr(III) occurs in the mixed diffusion-kinetic regime, irrespective of the kind of anions present in the aqueous phase.

Mass transfer of zinc(II) extraction from hydrochloric acid solution in the Lewis cell

Extraction of zinc(II) from model hydrochloric acid solutions was studied by Lewis cell mixing the bulks of both phases and keeping a stable interfacial surface. It was found that Lewis cell experiments, although dynamic in nature, support the extracting of ZnCl 2 *2 TBP and H 2 ZnCl 4 *2TBP chlorocomplex from model solutions containing 5 M Cl - and 0.55 MH + . The initial fluxes of zinc(II), HCl, Cl - , chloride present in the zinc(II) complex and water depend upon the concentration of tributyl phosphate and the mixing rates. The diffusion step in the organic phase gave a higher resistance to the mass transfer than the diffusion step in the aqueous phase. The physical transfer of small water molecules was less sensitive on the mixing rates than the transfer of bulky zinc(II) chlorocomplex.

COPPER EXTRACTION FROM CHLORIDE SOLUTION BY SOLVATING AND CHELATING EXTRACTANTS

The extraction of Cu(II) from chloride solutions at constant water activity aw and constant total concentration σ of species dissolved in the aqueous phase by di(2-ethylhexyl)pyridine-2,4-dicarboxylate (S), ACORGA CLX-50 (S) and LIX 54 (HL) used alone and in 1 : 1 mole/mole mixtures was studied. It was found that solvating reagents have a high ability of copper extraction from chloride solutions of low water activity and their extraction ability strongly depends on the chloride concentration. The extraction of copper(II) by LIX 54 is low in all systems studied (pH 2.4–3.9) and only slightly affected by chloride concentration. In the region of chloride concentration equal to 3–4 M approximately 90 and 50% of extracted copper is bound in the solvate with ACORGA CLX-50 for aw = 0.617 and σ = 12 M, and aw = 0.835 and σ = 8 M, respectively. Scrubbing with water at equilibrium pH above 4 permits almost complete transfer of chloride ions into the aqueous phase with the simultaneous conversion of copper(II) from the solvate CuCl2S2 in the chelate CuL2. Copper can be then stripped with 25–75 g/L H2SO4 and the organic phase recycled.

STRUCTURE and PROPERTIES of ALKANAL OXIMES as COPPER EZTRACTANTS

ABSTRACT Composition, structure and interfacial activity of alkanal oximes and kinetics of copper extraction from chloride solutions are discussed. Semiempirical self-consistent field calculations are used to study the structure of alkanal oximes and their mono- and dihydrates. These calculations are in a qualitative agreement with the ratio of alkanal (Z)-and (E)-isomers, interfacial activity and kinetics data.

Intelligent food packaging - research and development

Packaging also fosters effective marketing of the food through distribution and sale channels. It is of the utmost importance to optimize the protection of the food, a great quality and appearance better than typical packaged foods. In recent years, intelligent packaging becam e very popular. Intelligent packaging is becoming m ore and more widely used for food products. Application of this type of solution contributes to improvement of the quality consumer life undoubtedly. Intelligent packaging refers to a package that can sense environmental changes, and in turn, informs the users about the changes. These packaging systems co ntain devices that are capable of sensing and provi ding information about the functions and properties of the packaged foo s. Also, this paper will review intelligent pac k ging technologies and describe different types of indicators (time-te mp rature indicators, freshness indicators).

RATE OF COPPER EXTRACTION AND INTERFACUL ACTIVITY OF MODEL β-DHCETONES

ABSTRACT Interfacial tension isotherms and rate of copper extraction were studied for model β-diketones of LIX 54 and of pyrazolone type. The effect of the position and structure of the hydrophobic alky1 group upon interfacial activity and rate of extraction is discussed. The preadsorption of extractant molecules at the water/hydrocarbon interface is not needed to obtain a quick and effective extraction.

Utilization of agricultural and industrial wastes for metal removal from aqueous solutions

Utilization of agricultural and industrial wastes for metal removal from aqueous solutions In this study a possibility of obtaining sorbents from basketry wastes has been investigated. Therefore, adsorption of cadmium ions on wicker bark of Salix americana has been studied. The obtained experimental results were described by the Freundlich equation and adsorption kinetics by the pseudo-second order equation. The effect of pH on cadmium ions adsorption by S. americana was also investigated. It has been found that for the pH values ranging from 2 to 7 cadmium removal from the solution was held at almost constant level.

INTERFACIAL COMPLEXATION OF COPPER(II) FROM CHLORIDE SYSTEMS WITH EXTRACTANT BINARY MIXTURE

ABSTRACT The rate of copper(II) extraction from chloride solutions by commercial extractants: ACORGA CLX-50 and LIX 54 used alone and in equimolar mixture 1 : 1 mole/mole were studied. The interfacial tension and co-adsorption at the hydrocarbon/ water interface for systems containing the individual extractants and their mixtures were measured. For kinetics studies a moving drop method was used. The interfacial tension was measured by a drop volume method. It was found that the rate of extraction in binary mixed system is lower in comparison with the rate of copper(II) extraction by individual solvating extractant and strongly depends on the concentration of chloride ions in the aqueous phase. The amount of copper(II) extracted by LIX 54 used alone is very low. The interfacial activity of ACORGA CLX-50 in the toluene/water system is much higher in comparison with LIX 54. The observed decrease of copper(II) extraction rate in systems containing equimolar mixtures of solvating and chelating extractants in the organic bulk solution can be explained as a result of the co-adsorption of the both extractants at the hydrocarbon/water interface.