Oily wastewater is one of the major pollutants that occur in the metal industry and is very harmful to the environment, especially to aquatic life. All conventional methods such as dissolved air flotation, coagulation, adsorption, used during oily wastewater treatment have their advantages but none is as effective as membrane technology, which offers many possibilities regarding the applications of different materials, modules and pressures. The aim of this study was a comparison between the ceramic and polymeric membrane modules for model solutions (1%, 2% and 4% solutions of hydraulic fluid Ultra Safe 620 in acidic and alkaline mediums). The model solution was filtered on a laboratory scale by using two plants equipped with ceramic (Al2O3/ZrO2) and polymeric (PVC) membrane modules. The best result was obtained when using ceramic membranes where reversible membrane fouling was mainly presented, whilst in the case of polymeric membranes the irreversible membrane fouling was dominant. The physico-chemical analyses were performed by measuring pH, conductivity, turbidity, particle size and zeta potential, chemical oxygen demand, and lipophilic substances. Regarding substancesʼ removals, the ceramic membranes were more efficient compared to the polymeric ones.
COBISS.SI-ID: 17951766
Porous copolymers of styrene and divinylbenzene (DVB) were prepared by emulsion templating using high internal phase emulsions (HIPEs) as precursors for monoliths. The ratio of monomers was varied in order to obtain samples with different degrees of crosslinking and different amounts of unreacted vinyl groups originating from DVB. PolyHIPE monoliths were subjected to reswelling and treatment with a radical initiator. Significant enlargement of the amount of meso- and micropores in the material was found resulting in a substantial increase of BET surface area, up to 7.2 times compared to untreated polyHIPEs. The treated PolyHIPE monoliths retained the open macroporous morphology typical of polyHIPE materials. Solid state 13C NMR experiments were used to determine the amount of unreacted vinyl groups in polyHIPE samples, both before and after the hypercrosslinking treatment.
COBISS.SI-ID: 17174294
Highly porous monoliths with excellent mechanical properties and porosity of up to 90% were prepared by the polymerisation of high internal phase emulsions (HIPE) containing methyl methacrylate (MMA) and ethylene glycol dimethacrylate (EGDMA). Materials with open cellular morphology and cavity diameters between 0.6 and 4.5 microns are obtained using a homogenizer and between 0.8 and 25 microns using a standard overhead stirrer.
COBISS.SI-ID: 17975574
Nickel-copper (NiCu) alloy magnetic nanoparticles with narrow size distribution were prepared by reducing a NiCu oxide mixture in a silica matrix, obtained by a sol-gel method. In order to get NiCu nanoparticles, silica matrix was etched with etching solution in argon atmosphere. The Curie temperature can be adjusted by selectinga ppropriate composition. The method could be used in preparation of other mixed alloy nanoparticles.
COBISS.SI-ID: 17817110
Using water-in-oil emulsions with a high volume share of aqueous (droplet) phase as precursors (High Internal Phase Emulsions; HIPEs), highly porous polymers (polyHIPEs) were prepared from glycidyl methacrylate (GMA) and ethylhexyl acrylate (EHA), their morphology investigated and mechanical and chromatographic characteristics evaluated.
COBISS.SI-ID: 17661718