Volume 48 (2017): Issue 1-4 (December 2017)

This paper presents the possibility of receiving the granular forms of a zeolitic material of the Na-P1 type obtained from high-calcium fly ash in a semi-technical scale by means of three compacting techniques. The compaction process was carried out using cement, molasses and water glass as binders. Each of the proposed compacting methods affected the textural parameters of the obtained granular zeolite forms, as well as the binders used. In comparison to the other binders it was found that the cement binder had the smaller impact on the values of the textural parameters of the obtained compacted zeolite forms. The surface area for the zeolite Na-P1 was 98.49 m²·g^-1, for the cement as a binder was 69.23 m²·g^-1, for the molasses was 52.70 m²·g^-1and for the water glass was 40.87 m²·g^-1. For this reason, the briquetting and extruding tests were carried out using cement as a binder.

This paper summarizes information about recently worked bentonite deposits in Slovakia and presents the results of studies on bentonite from the Central Slovakia Volcanic Field (CSVF). The authors compared the mineralogy of commercial bentonites exploited in the Stara Kremnička (Jelšový potok), Kopernica, and Hliník nad Hronom deposits. X-ray diffraction (XRD), chemical analyses and microscopy showed that the main component is montmorillonite (37-88%), followed by opal C/CT (5-25%), clinoptilolite (up to 15%), feldspars (3-12%), quartz (up to 8%), biotite (2-5%), and kaolinite (up to 2%). The microscopic imaging provided information valuable for the technological assessment of bentonites, particularly the evaluation of mineralogy determined by XRD. The low variability of the mineral composition of commercial bentonites exploited in the western CSVF, together with the significant reserves and localization of deposits close to the Polish-Slovak state border prove that this raw material deserves more attention from Polish industry.

In water treatment plants, a large amount of wastewater and sludge is generated during the processing of drinking water. The composition of the sludge is determined by the type and raw water chemistry, as well as the methods and materials used for purification. The major components of the sludge are iron and manganese oxyhydroxides. In the past, the sludge was landfilled, but for environmental reasons it became necessary to find uses for the sludge. The aim of this study was to identify examples of using this sludge. Nowadays, the sludge is applied in the treatment of municipal wastewater, agriculture, and the production of cement and bricks, among others. Attention was also paid to the possibility of using the water processing sludge in different sorption applications.

Adsorption is considered as one of the most promising technologies for CCS. Gas adsorption involves the separation of gaseous components from flue gas using solid adsorbents. The gaseous component, adsorbate, is adsorbed from the gas phase on a solid material. Regarding CO₂adsorption, it is important to consider the parameters, that is the high sorption capacity, CO₂selectivity, regeneration and stability in multiple cycles. New directions for the development of adsorbents are focused on increasing their capacity - for this purpose, amine impregnation is carried out. This paper presents a new approach to obtaining mesoporous material from fly ash and, based on this, a new physico-chemical adsorbent obtained by impregnation. The effectiveness of the process was confirmed by thermogravimetric analysis and FTIR infrared spectroscopy.

This paper presents the legal aspects of the management of wastes that can be used as sorbents in environmental protection. The legal status of wastes with mineral characteristics - Carboniferous rock and mineral wool from horticulture - is discussed, where it is found that the number of legal acts cause difficulties in the utilisation of such wastes.

In this work, kaolinite modified with zero-valent iron was synthesized and used as a sorbent for Pb(II) and Mo(VI) removal from aqueous solutions. The obtained material was characterized by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The methods revealed successful modification by the Fe⁰particles precipitation on the surface of well-ordered kaolinite. The sorption experiment results showed a significant increase of sorption capacity in relation to the raw kaolinite. The kaolinite with 25% content of Fe⁰was found to be the best material for Pb(II) and Mo(VI) removal, resulting in approximately 500 mmol·kg^-1and 350 mmol·kg^-1sorption, respectively. The possible mechanisms responsible for metals’ removal were identified as reduction by Fe⁰‘core’ and adsorption on the iron hydroxides ‘shell’. The study indicated that the obtained material is capable of efficient Pb(II) and Mo(VI) removal and may be an interesting alternative to other methods used for heavy metals’ removal.

In Poland, by 2020 430,000 Mg of hazardous waste will be formed annually by the combustion of waste. This waste must be properly managed so as not to endanger the environment. One promising way to manage selected waste is to process it in the synthesis of materials characterised by sorption properties. The results presented in this paper concern the possibility of producing sorbents from waste materials marked with codes 190112 and 190114, which came from two waste incineration plants in Poland. Alkaline activation was performed using two methods: a) hydrothermal, in a solution of 8 M NaOH at 75°C for 24 h; and b) in an autoclave, using a solution of 2 M NaOH at 140°C for 6 h. XRD analyses led to the identification of materials after synthesis of the following zeolite phases: analcime, chabazite and thomsonite. chabazite and analcime can be valuable absorbent materials.

In this study, halloysite-Fe₃O₄composites were synthesized by a chemical-precipitation method to facilitate magnetic separation of the sorbents from aqueous solution. The research focused on the effect of Fe₃O₄phase on the halloysite sorption properties. The X-ray diffraction (XRD) results confirmed successful deposition of Fe₃O₄particles on a halloysite surface. They showed that the coating with Fe₃O₄particles enhanced the halloysite adsorption affinity toward Cd(II) and Pb(II). The highest adsorption capacity was determined for the composites having 10% of the surface deposited with Fe₃O₄. In this case, the adsorption capacity for Cd(II) and Pb(II) was 33 and 112 mmol·kg^-1, respectively. The point of zero charge (pH_PZC) and desorption results indicated that the removal mechanism of metals is mainly related to chemisorption involving reaction with hydroxyls of either halloysite or Fe₃O₄phase. The ion exchange is of limited importance due to the low cation exchange capacity (CEC) of halloysite - Fe₃O₄composites.

The study compared coal fly and bottom ashes for their ability to inactivate metals and lead to soil remediation. Soil was artificially contaminated with Cu, Zn, Pb and Cd at five degrees. Next, both ashes were added at five rates: 0, 0.5, 1.0, 1.5 and 2.0% and all treatments incubated. Data showed that for moderately contaminated soils, ash rates of 0.5 - 1.0% were efficient from 40 to 70% for Zn and Cd, and raised markedly to between 70 and 93% for Cu and Pb. For extremely contaminated soils, the rates of ashes at 1.0, 1.5 and 2% were much more efficient (60 - 80%). The use of fly and bottom ashes for metal inactivation and soil remediation should give greater consideration to the effect of pH and the type of heavy metals than the content of SiO₂and Al₂O₃. Fly ash displayed superior inactivation and remediation effects to the bottom ash.

The use of zeolites as sorbents has been investigated as a replacement for existing costly methods of removing organic contaminants from water solutions. Zeolites can be modified by inorganic salts, organic surfactants, metals or metal oxides in order to increase their adsorption capacity. The unique ion exchange and adsorption properties of zeolites make them very suitable for application in the removal of organic compounds such as volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), phenols and other complex petrochemicals. Many different studies have demonstrated their effectiveness in reducing the concentrations of organic contaminants as well as petroleum derivatives in water, which has been summarized in this paper.

This article discusses the impact of choosing a data preprocessing method for the calculated gas density necessary to determine the sorption capacity of a material. The sample of gas-bearing shale was subjected to a volumetric sorption test. The obtained data, pressure and temperature were preprocessed by three methods: moving average, polynomial regression and locally weighted scatterplot smoothing. The results include the excess and absolute sorption calculated from data that were filtered, and data without pre-treatment and Langmuir isotherms’ coefficients for every case.

This article presents the results of research into calcareous waste from the production process of oxide propylene. The obtained results show a considerable chemical diversity of calcareous waste with a predominant percentage share of Ca, C and Cl, which are the products of the process. It was shown that the share of calcium bonded in CaCO₃was over 20%, which is indicative of the secondary carbonisation process taking place in the waste. The morphological and structural analyses revealed that the grains had a surface area above 12% and a percentage porosity in the range of 25-35%. The reactivity test made it possible to classify calcareous waste as a material for sorbents of 'satisfactory' sorption properties, insufficient to be effectively used in the power sector. For the stored waste to be reused, it is necessary to improve its sorption abilities through the application of a properly selected activation method.