Synthesis via ozone precipitation reaction was used to obtain manganese dioxide (OMD) and it was probed as an adsorbent for zinc ions. Adsorption was followed along shaking time and increasing ratio [NO3−] / [Zn2+], and isotherms were obtained at different pH values and in the presence of several anions (chloride, nitrate, sulphate, and acetate). It was found that adsorption equilibrium is fast and follows the pseudo-second order model (qe = 34 ±1 mg/g and K = 0.07 ±0.01 g/mg h). Isotherms were fitted to Langmuir, Freundlich, and Langmuir-Freundlich models, and the best fitting was found with the last one. The process is dependent on pH and the efficiency increases from pH 1 to 4. The ratio [NO3−] / [Zn2+] up to 3 does not seem to change the behaviour of the process. Regarding the anions, the efficiency of Zn(II) adsorption occurs according to: acetate > nitrate and sulphate > chloride. Manganese oxide obtained via ozonization is an excellent adsorbent for zinc ions.
Jiří Moravec, Tomáš Jirout, František Rieger and Lukáš Krátký
Moravec, J. & Rieger, F. (2008). Rheological behavior of high-concentrated fine-grained suspension. Czasopismo Techniczne 5-M/2008, 231-238.
Rieger, F. & Moravec, J. (2007). Rheometry of the Fine Concentrated Suspensions. In Teoretičeskie osnovy sozdanija, optimizacii i upravlenija energo-i resursosberegajuščimi processami i oborudovaniem - Sbornik trudov, 2007, (pp. 75-83). Ivanovo, Russia. [in Russian].
Rieger, F. (1993). Efficiency of agitators while mixing of
The efficiency of lactic acid solutions nanofiltration with dynamically formed zirconium (IV) hydrous oxide polyacrylate (ZrIV/PAA) membranes application were considered in this paper. The results of investigations on flux decline in nanofiltration of lactic acid solutions under conditions resulting in low and high lactic acid rejection are reported. In the long term experimental research on pressure driven membrane processes the main reason of permeate flux reduction is an accumulation of concentration polarization and fouling effects. The experimental permeate flux versus time curves were analyzed in the frame of resistance-in-series model with the aim to develop the characteristic fouling and concentration polarization resistances. The analysis of experimental data and results of calculations showed that both: concentration polarization and fouling phenomena in investigated system depend on hydrodynamic conditions and properties of filtered solutions and (ZrIV/PAA) membrane.
Maria Kušnierová, Vladimír Šepelák and Ol'ga Šestinová
Bio-chemical methods in wasteprocessing
The mineral biotechnologies, the domain of which is primary raw material processing, are increasingly diversifying into some metallurgical areas. The presented results of the research carried out with metallurgical wastes from aluminium production, lead waste remaking and desulphurization zinc-ferrite-based sorbents regeneration prove the possibility of the use of bio-chemical methods. The results obtained and the proposed technologies applying bio-chemical processes enable a complex processing and use of waste sludge from aluminium production and the use of wastes from matte-based copper production for the production of hematite pigments. The use of microorganisms in the desulphurization sorbent regeneration processes allows to increase sorbent's efficiency and its repeated recycling.
Separation of volatile compounds from fermentation broth by membrane distillation
The diluted ethanol solutions and fermentation broth (Saccharomyces cerevisiae) were separated by membrane distillation (MD). Hydrophobic macroporous (pore size 0.2 μm) capillary polypropylene membranes, Accurel PP V8/2 HF and Accurel PP S6/2, were used for these studies. The MD process can be successfully applied to remove the volatile components from the fermentation broth. Besides ethanol, propionic and acetic acids were moved from the broth to the distillate. Therefore, the course of the fermentation carried out in a membrane distillation bioreactor considerably accelerate its rate and increase the efficiency by a selective removal of fermentation products. It was found that the broth subjected to the separation did not affect the hydrophobic properties of the polypropylene membrane assembled in the MD modules.
Marian Sułek, Tomasz Wasilewski and Emilia Klimaszewska
Preparations and production technologies of cleansing milks based on cenosphere obtained from flying ashes
Application of cenosphere obtained from flying ashes as effective abrasive for cleansing milks was analyzed in the paper. Preparations and production technology of ten milks with various contents of cenosphere (from 2% to 20%) were designed. The products were tested to determine their most important usable properties. The efficiency of application and dispersion, cleansing ability, ability to emulsify fatty soils and destructing activity, measured as polish of surfaces, were analyzed. Selected trade products were tested analogously. The results obtained show that cenosphere can be a good replacement of abrasives that are widely used. The cenosphere-based products revealed comparable usable properties to the trade products (or even better). It is probable that producers of cleansers will pay their attention to this waste, which will bring profits to the natural environment.
Justyna Ulatowska, Izabela Polowczyk, Wojciech Sawiński, Anna Bastrzyk, Tomasz Koźlecki and Zygmunt Sadowski
The objective of the present study is to assess the efficiency of fly ash and fly ash agglomerates to remove arsenic(III) from aqueous solution. The maximum static uptakes were achieved to be 13.5 and 5.7 mgAs(III)/adsorbent for nonagglomerated material and agglomerated one, respectively. Isotherm studies showed good fit with the Langmuir (fly ash) and the Freundlich (fly ash agglomerates) isotherm models. Kinetic studies indicated that the sorption of arsenic on fly ash and its agglomerates follows the pseudo-second-order (PSO) chemisorption model (R2 = 0.999). Thermodynamic parameters revealed an endothermic nature of As(III) adsorption on such adsorbents. The adsorption results confirmed that fly ash and its agglomerates can be used for As(III) removal from aqueous solutions. Fly ash can adsorb more arsenic(III) than agglomerates, which are easier to use, because this material is less dusty and easier to separate from solution.
Krzysztof Perkowski, Janusz Sokołowski and Mikołaj Szafran
Usability of high porosity ceramics for the separation of oily impurities
Organic impurities fallen to the ground water and to surface waters (rivers, lakes, seas and oceans) contribute to the degradation of the fauna and flora. Taking into account the public welfare, as the natural environment is, studies have been undertaken to develop a cheap and effective system for the purification of water from finely dispersed petroleum derivatives. The idea of the solution proposed consists in using a separator with high porosity ceramics of the pore size up to 100 ¨m, of high water permeability and ability to separate oily impurities of very tiny particle size. To improve the efficiency of the process the affinity of the filtering surface to organic particles was increased by the use of water-repellent media. The process of the separation of oily impurities was enhanced by means of ultrasounds of the 18 kHz frequency and various vibration energies.
Barbara Walawska, Joanna Gluzińska, Korneliusz Miksch and Jolanta Turek-Szytow
Solid inorganic peroxy compounds in environmental protection
The paper presents a solid inorganic peroxy compounds description (calcium peroxide, magnesium peroxide and sodium percarbonate) focused on the properties and environmental application, particularly for the degradation of polycyclic aromatic hydrocarbons (PAHs) and phenols in soil environment. Modern technological processes require the use of compounds that are safe for the environment, non-toxic, easily degradable to the products, which themselves have no adverse environmental effect. Peroxides, as the chemical compounds, produce an effect on the enzymatic activity of the environment into which they are introduced. A good indicator of the activity of soil, bottom sediment or activated sludge, may be the dehydrogenase activity, which is a reflection of the general physiological state of microorganisms. Peroxides can be applied both in a pure form, as well as in mixtures with certain other groups of compounds. To enhance their efficiency they can be mixed with nitrogen, phosphorus or potassium carrying compounds.
Karol Fijałkowski, Anna Żywicka, Radosław Drozd, Marian Kordas and Rafał Rakoczy
The aim of the study was to analyze the changes in the parameters of bacterial cultures and bacterial cellulose (BC) synthesized by four reference strains of Gluconacetobacter xylinus during 31-day cultivation in stationary conditions. The study showed that the most visible changes in the analyzed parameters of BC, regardless of the bacterial strain used for their synthesis, were observed in the first 10–14 days of the experiment. It was also revealed, that among parameters showing dependence associated with the particular bacterial strain were the rate and period of BC synthesis, the growth rate of bacteria anchored to the cellulose fibrils, the capacity to absorb water and the water release rate. The results presented in this work may be useful in the selection of optimum culturing conditions and period from the point of view of good efficiency of the cellulose synthesis process.