Milan Búgel

Microfiltration of Concentrated Suspensions of a Microparticulate Ion‐Exchanger Through a Ceramic Membrane

Abstract Suspensions of a microparticulate Lewatit ion‐exchanger can be effectivelly concentrated by microfiltration (MF) to relatively high concentrations of about 25% of dry particles. This is important for formation of a hybrid process combining ion‐exchange and MF. A tubular ceramic membrane with the mean pore size of 0.1 µm and the ground ion‐exchanger Lewatit S100 with the mean particle size 5.25 µm have been used. Analysis of the flux decline revealed that the dominant membrane fouling mechanism is cake formation. With increasing suspension velocity the permeate flux significantly increases. The velocity of suspension above 2 m · s−1 should be used to achieve a reasonable flux. The limiting flux was reached at a pressure of about 100 kPa, but at higher suspension concentrations even at about 60 kPa. Surprisingly, the dependence of the permeate flux vs. suspension concentration goes through a flat maximum at the mass fraction of the dry resin of about 0.13. This can be interpreted as a result of inertial lift of larger particles in the suspension. At higher ion‐exchanger concentrations further accumulation of particles in the cake increases its resistance and decreases the flux. Even at concentrations as high as 37.5 mass% of wet (25% of dry) particles in the suspension the permeate flux of about 72 dm−3 · m−2 · h−1 can be achieved.

Influence of Transmembrane Pressure on Microfiltration of Suspensions

The influence of transmembrane pressure on the permeate flux, and the critical and limiting fluxes in microfiltration of two sorbents Bentonite a natural sorbent, montmorillonite based clay and Lewatit S1468 a synthetic sorbent, styrene-divinylbenzene based copolymer were studied. An asymmetric single-channel inorganic ceramic membrane based on α-Al2O3 was used. The experimental data were obtained by continuous microfiltration equipment. According to the results the limiting flux ranged from 37 to 70 l.m-2.h-1 for Bentonite suspensions. It was not possible to estimate the limiting flux for Lewatit S1468 suspension.

Influence of Inner Configuration of Membrane on Microfiltration of Suspensions

The influence of membrane type on the permeate flux in microfiltration of two sorbents Bentonite a natural sorbent, montmorillonite based clay and Lewatit S1468 a synthetic sorbent, styrene-divinylbenzene based copolymer was studied. Two types of membranes, single-and multi-channel, both asymmetric inorganic ceramic membranes based on α-Al2O3, were used. The experimental data were obtained by continuous microfiltration equipment. According to the results use of multi-channel membrane has more advantages higher permeate flux, lower energy consumption, and lower flow rate than disadvantages longer time period to reach the steady state and higher pressure loss.

Hybrid Sorption and Microfiltration Characteristics of Zeolite

Industrial wastewater treatment and reuse is one of the principal tasks of present. For this purpose several physical, chemical and combined methods have been used. This paper deals with the study of sorption behaviour of natural zeolite with respect to Zn (II) and Cu (II) followed by cross-flow membrane microfiltration. The experiments realised were aimed at verification of effectiveness of ion exchange of selected metals from wastewater using zeolite – with main component clinoptilolite. The experimental data obtained were fitted using Langmuir and Freundlich isotherms. The sorption capacity was studied for zinc and copper uptake, followed by a study of microfiltration of zeolite suspension using a cross-flow microfiltration device with tubular ceramic membrane. According to experimental results the basic parameters of microfiltration process were evaluated. In comparison with other processes, the hybrid membrane microfiltration offers more effective way of water treatment.

The Use of Renewable Sources of Energy in the Development Process of a Slovak Municipality

The present article deals with the issue of renewable energy sources for the development needs of Čakanovce municipality in terms of solar, geothermal, and biomass energy which are available for this region. Using renewable energy is viewed not only in the context of environmental benefits, but also in the context of further socio-economic development of communities and an increase of its energy independence. The analysis of the solved problems was based on relevant data on the possibilities of using different types of renewable energy in relation to supporting the development of Olšava-Kecerovce region which also includes Čakanovce. Choice of the most appropriate types of renewable energies to promote further development of Čakanovce municipality was based on proportionately index method, according to pre-defined decision-making factors.