Zygmunt Sadowski

Biosorption of malachite green by eggshells: Mechanism identification and process optimization

In the present work, eggshells were used to remove a dye (malachite green) from wastewater. The study was focused on identification and describing the binding mechanism of the dye by eggshells in a biosorption process optimized by Response Surface Methodology based on the Box-Behnken Design. The mechanism of biosorption was determined by characterization of the biosorbent before and after biosorption using scanning electron microscopy, X-ray diffraction analysis, the Brunauer-Emmett-Teller isotherm method, Fourier transform infrared spectroscopy. The second-order polynomial equation and 3D response surface plots were used to quantitatively determine the relationships between dependent and independent variables. The obtained results suggested the mechanism of wastewater treatment that included physical adsorption, alkaline fading phenomenon and microprecipitation. The results of the present study showed that waste eggshells have the potential to be used as an inexpensive but effective biosorbent useful in wastewater treatment.

A study on hydrophobic aggregation of calcite aqueous suspensions

Abstract The behaviour of aqueous calcite dispersions in the presence of sodium oleate with and without n-heptane has been investigated. Calculations based on the classical Deryaguin, Landau, Verwey, Overbeek (DLVO theory show that there is an energy barrier between the calcite particles for both systems. This result does not correlate with experimental findings. Inclusion of a hydrophobic interaction energy term in the total potential energy of both systems markedly improved the agreement between theoretical and experimental data. It is further shown that hydrophobic interactions play a dominant role in the aggregation of particles.

Selective spherical agglomeration of fine salt-type mineral particles in aqueous solution

Abstract Salt-type minerals dispersed in aqueous solution with sodium oleate were spherically agglomerated at the critical surfactant concentration. When the pH range corresponded to the pH PZC of carbonate minerals, the spherical agglomeration disappeared. The selective separation of barite from a carbonate mineral suspension (ratio 1:1) was realized when sodium lignin sulphonate was added using the spherical agglomeration procedure. The effect of adding sodium lignin sulphonate was analyzed using FT-IR spectroscopy and thin-layer wicking techniques. The results suggest that the addition of the modifier changes the hydrophobicity of the surface and probably prevents the adhesion of bulk precipitated surfactant salts to the carbonate mineral surfaces.

The role of surfactant salts on the spherical agglomeration of hematite suspension

Abstract With the recognition of the importance of beneficiation of fine mineral particles, there has been a tremendous increase in research to aid our understanding of the role of precipitated surfactant salts in the spherical agglomeration process. In turn this has led to the development of special techniques for instance: ζ-potential and contact angle measurements, to explain this process. This work provides information on the condition of spherical agglomeration of fine hematite suspensions and it better characterizes a more detailed look at some problems of adhesion of surfactant salts.

The spherical oil agglomeration of barite suspensions in the presence of surfactant and cosurfactant

Abstract The spherical agglomeration of barite particles using oil in the presence of both surfactant and cosurfactant was studied. It was found that the mineral suspension needed a critical surfactant concentration to initiate oil agglomeration. The addition of long-chain aliphatic alcohols to the organic phase decreased the critical surfactant concentration. This phenomenon was ascribed to a screening effect of alcohol molecules in the adsorption layer of surfactant. When sodium chloride was added to the solution the spherical agglomeration disappeared even though the surfactant adsorption at the barite/solution interface increased. It was concluded that the disappearance of oil agglomeration was caused by a bilayer of the surfactant which was formed on the barite surface. In the barite—surfactant—alcohol—oil—brine system the agglomeration process is only realized with the long-chain alcohols. This behaviour can be explained by microemulsion formation at the mineral/solution interface.

The stability of semi-soluble salt type mineral suspensions in oleate solution

ABSTRACT Finely divided single and binary barite-carbonate mineral stabilities were studied as a function of oleate concentration at constant pH 10. The zeta potentials of the individual minerals were determined as functions of oleate concentration as were also the concentrations of appropriate cations in the supernatants of the single mineral suspensions. The effect of the presence of polyethylene oxide and sodium lignin sulfonate on the behavior of the suspensions was also determined. The conditions necessary for flocculation or dispersion of suspensions were interpreted in terms of oleate solution chemistry, the orientation of oleate ions at the solid solution interfaces and the influence of Ca2+, Mg2+ and Ba2+ ions in the system; all of these items as modified by the sometimes presence of polyethylene oxide or sodium lignin sulfonate.

THE EFFECT OF DISPERSANT REAGENTS ON THE SODIUM OLEATE ADSORPTION AT THE SALT MINERALS-WATER INTERFACE

Abstract The influence of some dispersant reagents on the sodium oleate adsorption on the salt minerals surface has been investigated at the vicinity of pH 10. The presence of sodium lignin sulfate and low molecular weight acrylic polymer Cataflot P-40 caused the decrease of surfactant adsorption in the low concentration region of sodium oleate. On the other hand, the addition of 1000 g/t of polyethylene oxide (MW 200 000) did not cause such a change. The special shape of the adsorption isotherms has been done by the bidimensional concentration of alkaline earth metals soaps on the carbonate minerals surfaces. The vertical steps of isotherms were shifted to the high sodium oleate concentration region when both sodium lignin sulfate and Cataflot P-40 were added to the dolomite and magnesite suspensions. This effect was not observed for the calcite-sodium oleate system. The discrepancy was explained by Die blockade of magnesite species by these dispersant reagents. Changes in electrokinetic and stability be...

A View on the Organic Matter and Metalloporphyrins Biodegradation as Characteristic Components of Black Shale Ores

High content of organic compounds is characteristic for black shale-type ores. Metalloporphyrins are known as the most stable and resistant for biodestruction compounds of organic matter. Based on results obtained in previous studies, four metalloporphyrins were synthesised [1]. The experiments of biodestruction of organic matter extracted from polish black shale ore samples and of the synthetic metalloporphyrins were provided using autochthonous, heterotrophic bacteria mixtures isolated form polish black shale samples, and two Streptomyces species. It was found that biodestruction of black shale organic matter and copper- and vanadylporphyrins is possible, but it is a long term process. Porphyrins of Ni and Fe were resistant to biodegradation.

Characterization of Glass Beads Surface Modified with Ionic Surfactants

Knowledge of the wetting characteristic of mineral surfaces is very important in enhancing the efficiency of separation of valuable minerals from gangue using froth flotation or oil agglomeration. In this paper a capillary rise technique was used to characterize the glass beads surface modified with cationic surfactant. The glass microspheres were used as model particles with a spherical shape and smooth surface to eliminate the roughness effect. The value of the contact angle for water was found to be 21.5 for unmodified beads, and 61.8, 89.7, 68.4 for 0.1, 1.0, 10 mg/gsolid of CTAB, and 39.8, 68.6, 87.9 for 0.1, 1.0, 10 mg/gsolid of DDAHCl, respectively. Data revealed that the adsorption of surfactant onto glass beads decreased the value of the electron donor component, γ-, which defines the hydrophobicity of the surface. Also, the property of the surface was investigated by flotation and oil agglomeration experiments. It was observed that particles with low value of contact angle for water and high for 1-bromonaphthalene and low value of γ- were floated with a recovery equal to 91.1 and 83.1% for CTAB and DDAHCl, respectively, and effectively agglomerated. This indicates that the capillary rise method can be successfully used to predict the wetting properties of solid particles in mineral processing.

Influence of Hydrophobicity on Agglomeration of Dolomite in Cationic-Anionic Surfactant System

In this study the modified procedure of the oil agglomeration process was carried out, where the emulsion of dodecylammonium hydrochloride (DDAHCl) solution and kerosene was added to the mineral suspension. The aim of this work was to research the oil agglomeration of dolomite mineral by the contact angle, zeta potential and surface free energy measurements. The relationship between the investigated parameters and the oil agglomeration as well as shear flocculation was revealed. The mechanism of oil agglomeration of hydrophilic particles in cationic-anionic surfactant system has been proposed. It was concluded that oil droplets interact rather with aggregates of particles modified by anionic surfactant than the single mineral particles as was explained for naturally hydrophobic particles.