Wyniki wyszukiwania - BazTech

1

Sorbenty w oczyszczaniu ścieków

Bajda T.

Przegląd Komunalny

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2017

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nr 7

44--46

PL

Rynek oczyszczania wody w Polsce Frost & Sullivan oszacował w 2013 r. na kwotę 640 mln dolarów. Co więcej, największą popularnością w tym zakresie cieszą się metody chemiczne.

2

Sorbenty dla środowiska

Bajda T.

Przegląd Komunalny

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2017

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nr 3

49--51

PL

Stosowanie sorbentów mineralnych nie tylko przyczynia się do poprawy stanu środowiska naturalnego, ale także wpływa na wzrost konkurencyjności przemysłu i tworzenie innowacyjnych technologii.

3

Jak skutecznie(j) oczyszczać ścieki?

Bajda T.

Przegląd Komunalny

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2017

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nr 11

57--59

PL

Klasyczne, wysokoefektywne metody oczyszczania ścieków przemysłowych są niewystarczające wobec zawartych w ściekach bardzo wysokich stężeń zanieczyszczeń. Pomocne w usuwaniu zanieczyszczeń mogą okazać się powszechnie stosowane materiały sorpcyjne.

4

Third Scientific and Technical Conference "Minerals Sorbents", Raw Materials, Power Engineering, Environmental Protection, Modern Technologies, 18–19 September 2017, Cracow

Bajda T.

Mineralogia

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2017

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Vol. 48, iss. 1/4

1--2

EN

We present an issue containing articles that were presented at the Third Scientific and Technical Conference "Minerals Sorbents", Raw Materials, Power Engineering, Environmental Protection, Modern Technologies, which took place on 18–19 September 2017 in Cracow. The conference was a great forum for exchanging experiences, presenting the latest research achievements of the country's leading scientific units to the representatives of the key industry sectors whose production technologies are based on the use of mineral sorbents.

5

The removal of organic compounds by natural and synthetic surface-functionalized zeolites: a mini-review

Muir B., Wołowiec M., Bajda T., Nowak P., Czupryński P.

Mineralogia

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2017

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Vol. 48, iss. 1/4

145--156

EN

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.

6

Current stage of knowledge relating to the use ferruginous sludge from water treatment plants – a preliminary review of the literature

Wołowiec M., Bajda T.

Mineralogia

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2017

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Vol. 48, iss. 1/4

39--45

EN

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.

7

Characteristics of sorbent products obtained by the alkaline activation of waste from waste incineration plants

Grela A., Łach M., Bajda T., Mikuła J.

Mineralogia

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2017

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Vol. 48, iss. 1/4

87--105

EN

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.

8

Usuwanie wybranych związków biogennych z roztworów wodnych z wykorzystaniem metakaolinu i zmodyfikowanego metakaolinu

Grela A., Bajda T.

Inżynieria Ekologiczna

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2017

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Vol. 18, nr 2

30--38

PL

Celem pracy było dokonanie oceny skuteczności usuwania związków biogennych, jonów NH4+, NO3-, PO43- z roztworów jednoskładnikowych (o stężeniach z zakresu 0,3-16,7 mmol/dm3) oraz trójskładnikowych (o sumarycznym stężeniu trzech jonów 0,9-50,1 mmol/dm3). W badaniach wykorzystano metakaolin firmy Rominco (M) oraz produkt modyfikacji metakaolinu, zawierający zeolity (M2, M3). Eksperymenty sorpcji prowadzone były w warunkach statycznych. W roztworach równowagowych oznaczono stężenia NH4+, NO3-, PO43-, metodą kolorymetryczną przy użyciu spektrofotometru UV-Vis. Materiał M2 okazał się najbardziej skutecznym w usuwaniu związków biogennych zarówno w przypadku roztworów jedno jak i trójskładnikowych. Wynika to głównie z większej powierzchni właściwej (BET) materiału M2 (328,2 m2/g), niż materiału M (13,2 m2/g). Modyfikacja materiału M spowodowała, że skuteczność usuwania związków biogennych uległa zwiększeniu. Z największą (około 90%) skutecznością usuwane były jony NH4+ zarówno z roztworów jedno jak i trójskładnikowych. Z dużą (około 50%) skutecznością usuwane były jony PO43- zarówno z roztworów jedno jak i trójskładnikowych. Z najmniejszą (10%) skutecznością usuwane był jony NO3- z roztworu jednoskładnikowego i ponad 30% skutecznością z roztworu trójskładnikowego.

EN

The main purpose of this paper was to assess the effectiveness of the removal of biogenic compounds, NH4+, NO3-, PO43- from single-component solutions (with concentrations ranging from 0,3–16,7 mmol/dm3) and ternary solution (with a total concentration of three of ions 0,9–50,1 mmol/dm3). In the research the Romanico (M) metakaolin was used as well as a product of modification of metakaolin containg zeolites (M2, M3). Sorption experiments were conducted under static conditions. In equilibrium solutions the concentrations of NH4+, NO3-, PO43- were determined by colorimetric method using a UV-Vis spectrophotometer. The M2 was the most effective in the removal of nutrients in both solutions (single-component and ternary). This is mainly due to the larger specific surface area (BET) of M2 material (328,2 m2/g) than the material M (13,2 m2/g). Modification of the material M has resulted in increased removal efficiency of nutrients. In most (about 90%) efficiency NH4+ ions (from either single-component and ternary solutions) were removed. With a large (about 50%) efficiency PO43- ions (from either single-component and ternary solutions) were removed. In the lowest (10%) efficiency the NO3-ions from the single-component solution were removed and with more than 30% efficiency the ternary solution were removed.

9

Alkaliczna aktywacja popiołów po spalaniu mułów węglowych

Grela A., Łach M., Bajda T., Mikuła J.

Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN

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2016

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nr 95

181--191

PL

Muły węglowe powstają w procesach wzbogacania węgla w zakładach przeróbki mechanicznej kopalni węglowych. Mogą być wykorzystywane przy wytwarzaniu mieszanek energetycznych lub też składowane w osadnikach. Po spaleniu mułów pozostaje kilkadziesiąt procent popiołów, które warto w odpowiedni sposób zagospodarować. Niniejsza praca opisuje koncepcję wykorzystania popiołu ze spalania mułów węglowych do wytwarzania sorbentów i materiałów zeolitowych. Badany popiół aktywowany był roztworem wodorotlenku sodu o stężeniu 5 M w dwóch temperaturach (75°C i 175°C). W pracy przedstawiono charakterystykę fazową i chemiczną produktów syntezy. Zastosowanie skaningowej mikroskopii elektronowej pozwoliło na opis powstałych form morfologicznych. Wykonano analizy składu chemicznego oraz wyznaczono parametry tekstualne powstałych materiałów. Przeprowadzone badania pozwalają stwierdzić, że synteza w środowisku alkalicznym popiołów ze spalania mułów węglowych prowadzi do zmiany morfologii tych popiołów. Dominującymi składnikami mineralnymi produktów syntezy są zeolity: faujasyt i sodalit, którym towarzyszą nie przereagowane składniki wyjściowego popiołu: skalenie, kwarc, illit, kalcyt. Analiza SEM wykazała obecność żelu glinokrzemianowego. Stwierdzono ponad czterokrotny wzrost powierzchni właściwej (BET) produktu alkalicznej aktywacji w temperaturze 75°C. Stwarza to potencjalne możliwości zastosowania takich materiałów jako sorbentów.

EN

Mules carbon are formed in the process of coal beneficiation in coal mines mechanical processing plants. They can be used in the manufacture of energy compound or stored in settling ponds. Following the burning of sludge tens of percent ash remains, which should develop in the right way. This paper describes the concept of using ash from the combustion of coal slurry to produce sorbents and zeolite materials. Tested ash was activated with a solution of sodium hydroxide at a concentration of 5 M in two temperatures (75°C and 175°C). The paper presents the phase and chemical characteristics of synthesis products. The use of scanning electron microscopy allowed for the description of the resulting morphological forms. Analysis of the chemical composition and determination of parameters textural resulting materials were performed. The studies lead to the conclusion that the synthesis of the alkaline ashes from the combustion of coal slurry results in a change of morphology of these ashes. The dominant mineral components of products synthesis are the zeolites: faujasyt and sodalite, accompanied by unreacted components of the output ash: feldspar, quartz, illite, calcite. SEM analysis showed the presence of the aluminosilicate gel. It was found more than 4-fold increase in surface area (BET) of the product of alkaline activation at 75°C. This creates the potential use of these materials as sorbents.

10

Content of PAHs, activities of γ-radionuclides and ecotoxicological assessment in biochars

Gondek K., Mierzwa-Hersztek M., Smreczak B., Baran A., Kopeć M., Mróz T., Janowski P., Bajda T., Tomczyk A.

Polish Journal of Chemical Technology

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2016

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Vol. 18, nr 4

27--35

EN

The aim of this research was to determine the effect of thermal conversion temperature and plant material addition to sewage sludge on the PAHs content and the activity of selected γ-radionuclides in biochars, and to conduct an ecotoxicological assessment. The pyrolysis of the mixtures of sewage sludge and plant materials at 300°C and such temperature caused an increase in the contents of 2- and 3-ring hydrocarbons. During the pyrolysis of organic materials at 600°C, the amount of the following compounds was reduced in biochars: benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, indeno[1,2,3c,d]pyrene, dibenzo[a,h]anthracene, and benzo[g,h,i]perylene. Among γ-radioisotopes of the elements, natural radiogenic isotopes were dominant. 137Cs was the only artificial radioactive isotope. The pyrolysis of the mixtures of municipal sewage sludge and plant materials revealed that isotope 40K had the highest radioactive activity. In the case of other analysed nuclides, activities of 212Pb, 214Pb, 214Bi, and 137Cs were determined after the sample pyrolysis. The extracts from the mixtures of sewage sludge and plant materials were non-toxic to Vibrio fischeri.

11

The Rietveld refinement studies of pyromorphite-vanadinite and mimetite-vanadinite solid solution series

Solecka U., Zelek S., Bajda T.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

127--128

EN

Mimetite Pb 5 (PO 4 ) 3 Cl, vanadinite Pb 5 (VO 4 ) 3 Cl and pyromorphite Pb 5 (PO 4 ) 3 Cl belong to the apatite supergroup. They form in oxidation zones of lead ore deposits. These minerals have high thermal stability (Dong et al. 2002) and low solubility (Flis et al. 2011) thus they have many applications. Pyromorphite and mimetite are especially used to immobilize lead in contaminated soils and hazardous industrial wastes (Ma et al. 1993, Kim et al. 2005, Bajda et al. 2007), it is therefore important to know the impact of various factors on their properties. Crystal structure of apatites corresponds to the general formula M 5 (TO 4 ) 3 X, where M are bi - valent cations distributed on two distinct crystallographic sites, TO 4 is a trivalent oxyanion and X is a monovalent anion. The structure and chemistry of apatite allow for numerous substitutions of metal cation and anionic complexes (Hughes & Rakovan 2002, Pan & Fleet 2002). It was found that substitutions cause variations in the unit cell parameters and chemical properties of these minerals (Botto et al. 1997), but there are no articles presenting variations in the whole series. Therefore, these researches present changes of lattice parameters for pyromorphite-vanadinite and mimetite-vanadinite solid solution series. Pyromorphite, mimetite and vanadinite crystallize in hexagonal symmetry (the space group P6 3 /m) (Dong et al. 2002, Pan & Fleet 2002). They form continuous isomorphic series. The aim of study was to examine how lattice parameters of pyromorphite-vanadinite and mimetite-vanadinite solid solutions series change with increasing vanadium content and characterize these pheno mena. Crystallographic studies were conducted on synthetic pyromorphite, mimetite and vanadinite and minerals with intermediate compositions Pb 5 (TO 4 ) 3 Cl, where T = P + V or As + V, of various P/V or As/V ratios. Samples were analyzed by X-Ray diffraction (XRD) using RIGAKU Smartlab X-Ray diffractometer with Cu radiation in a 10° to 110° 2Θ range at a step size of 0.02 2Θ and a rate of 2 s per step. The phase identification was carried out using the X’Rayan computer program and X-ray standard patterns in the form of ICDD files (card 19-0701, 19-0683 and 43-1461). The unit-cell refinement and Rietveld structure refinement were made using the FullProf Suite computer program package (Rodriguez-Carvajal 1993). The Rietveld refinement has shown systematic changes in unit cell parameters of studied samples depending on their chemical composition. Dimensions of unit cell parameters of pyromorphite-vanadinite solid solution series increase linearly with the substitution of vanadate ions in the structure of pyromorphite. Lattice parameter “a” increase in the range of 9.987–10.325 Å, while lattice parameter “c” increase in the range of 7.33–7.343 Å. In case of the mimetite-vanadinite solid solution series, lattice parameter “a” increase (10.251–10.325 Å range), whereas lattice parameter “c” decrease (7.442–7.343 Å range) linearly with the substitution of vanadate ions in the structure of mimetite. This situation indicates the equivalent position of the tetrahedral TO 4 in the structure of lead apatite.

12

Sorption of organic compounds by organo-zeolites

Wołowiec M., Muir B., Bajda T.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

139--140

EN

Organic compounds such as BTEX and PAHs are one of the most common contaminants in water system. These contaminants would take decades to degrade and they have harmful effects on human health (Qin et al. 2008). Several treatment methods have been developed to remove those contaminants from industrial wastewater. They include ion-exchange, filtration, adsorption and the use of various types of sorbents for example zeolites (Kibazohi et al. 2004, Mathur et al. 2007, Aivaliotiet al. 2012, Almeida et al. 2012). Natural clinoptilolite (Cp) from the Bystré deposit in Slovakia and zeolite Na-X synthesized from fly ash has been modified with a hexadecyltrimethyl ammonium bromide (HDTMA) in amounts of 1.0 and 2.0 of external cation exchange capacity (ECEC) of the zeolites (Szala et al. 2013). The sorption properties of unmodified zeolites and organo-zeolites in terms of aqueous solutions of benzene, ethylobenzene, toluene, p-xylene (BTEX) and their mixtures as well as anthracene, naphthalene, benzo[a]pyrene, dibenzo[a,h]anthracene (PAHs) and their mixtures at different concentrations were evaluated. The results showed that the modification of the zeolite Na-X and Cp with HDTMA improves the sorption properties. Modification in the amount of 1.0 ECEC proved to be the best in terms of p-xylene, anthracene, naphthalene, benzo[a]pyrene, dibenzo[a,h]anthracene. On the other hand benzene, ethylobenzene and toluene were adsorbed the most effectively by 2.0 ECEC modification of Na-X and Cp. Based on experimental data, the removal efficiencies for BTEX follows the order: p-xylene > toluene > benzene > ethylobenzene, for POHs: dibenzo[a,h]anthracene > benzo[a] pyrene > anthracene > naphthalene. P-xylene and naphtalene were adsorbed in the greatest quantity and benzene and anthracene in the lowest quantity from the mixtures of BTEX and PAHs, respectively. The sorption efficiency depends on the physicochemical properties of the organic compounds (dipole moment, molar mass, molecule structure and the time of the sorption process) as well as natural Cp and synthetic zeolite Na-X properties, such as Si/Al ratio, texture parameters and external cation exchange capacity. With an increasing concentration of the hydrocarbons in the solution the sorption capacity increases (Szala et al. 2015). Natural Cp is a better sorbent than synthetic zeolite Na-X in case of BTEX sorption, while PAHs are adsorbed more effectively by zeolite Na-X and its modifications. The mechanism of the sorption consists on the dissolving of the organic compounds into the organic layer of the surfactant (on the zeolites’ surface) as well as on the organic compounds’ penetration into the mesopores.

13

Molybdates and tungstates sorption on organo-smectites as a process controlled by the type and amount of surfactant

Muir B., Andrunik D., Bajda T.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

102--103

EN

Modification of a smectite with organic surfactants leads to the formation of an organo-mineral complex characterized by a positive charged (Baj da et al. 2015). The process involves the exchange of naturally occurring cations, e.g. Ca 2+, Mg 2+, Na +, K + by large organic cations of surfactants. This alteration makes it possible to use organo-smectites as sorbents to remove anionic forms of Mo(VI) and W(VI) from aqueous solutions. The concentration of molybdenum in the environment is significantly enhanced by anthropogenic inputs from coal-resource development, fly ash, sewage sludge and hard-rock mining activity (Kalembkiewicz & Sočo 2009). W(VI) is released to the environment through its use in winter tires or by its applications in industry e.g. enriches alloys or electrotechnics (Gustafsson 2003). The environmental behavior of molybdenum and tungsten becomes very complex once they dissolve as Mo(VI) and W(VI) anions occur as a monomer only in alkaline or neutral solutions. Bentonite from the Jelšovy Potok in Slovakia, rich in montmorillonite phase, was used in the sorption experiments (Bajda et al. 2015). Through the preparation of a series of experiments it was possible to define the impact of various surfactants, their amount and organo-smectites’ properties order on the sorption capacity and pH effect. Smectite has been modified with dodecyltrimethylammonium bromide (DDTMA), didodecyldimethylammonium bromide (DDDDMA), hexadecyltrimethylammonium bromide (HDTMA) and dihexadecyldimethylammonium bromide (DHDDMA) in amounts of: 0.5, 1.0 and 2.0 of cation exchange capacity (CEC). Experiments of Mo(VI) and W(VI) sorption on organo-smectites were conducted under various concentrations of Mo(VI) and W(VI) (0–20 mM) and in wide range of pH’s (1–13). The effectiveness of modifications follows the order DDTMA-smectite > HDTMA-smectite > DDDDMA-smectite > DHDDMA-smectite. The unmodified smectite did not remove Mo(VI) and W(VI) anions from the aqueous solution at all. In the removal of Mo(VI), sorption efficiency follows the order: DDTMA-smectite > DDDDMA-smectite > HDTMA-smectite > DHDDMA-smectite. In case of W(VI) the efficiency of the removal can be place: DDDDMA-smectite > DDTMA- -smectite > HDTMA-smectite > DHDDMA- -smectite. With an increasing concentration of Mo(VI) or W(VI) in the solutions, the sorption increases. The maximum sorption capacity in the removal of Mo(VI) was 1710 mmol Mo(VI)/kg in case of smectite modified with DDTMA at 0.5 CEC. The best result of tungsten sorption was 5882 mmol W(VI)/kg and it was obtained for DDDDMA-smectite (0.5 CEC). Results showed that the sorption is more effective at a lower pH, in both Mo(VI) and W(VI) removal. The smectite modified with surfactant with double carbon chain (DDDDMA, DHDDMA) proved to be a better sorbent. With an increasing amount of surfactant attached to the smectite, the sorption efficiency increases.

14

Arsenic interactions with bog iron ores – As(III) and As(V) adsorption-desorption study

Tuchowska M., Bajda T., Rzepa G., Dębiec K., Drewniak Ł.

Geology, Geophysics and Environment

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2016

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Vol. 42, no. 1

133--134

EN

Arsenic is a toxic element, elevated concentration of which in the environment can result from both anthropogenic activity and natural geochemical processes. The contamination of water, especially groundwater, with As has been recognized as a major environmental problem (Choong et al. 2007). The mobility and toxicology of As is related to its valence state which can be (+III) or (+V), depending mainly on pH and redox conditions. Because even low As concentrations in drinking water causes severe health effects, the technologies of its effective removal are thought to be very important (Mohan & Pittman 2007). Among many methods developed for removing aqueous arsenic species, the adsorption onto iron oxyhydroxides or oxyhydroxide-rich sorbents is one of the most effective. Despite many studies, the factors affecting the adsorption processes, especially those related to the sorbent properties, are still far from being fully understood (e.g. Adra et al. 2016). In this work we investigated As(III) and As(V) adsorption and desorption by bog iron ores – natural ferruginous sediments which have been recently demonstrated to exhibit very good sorption properties. For this study four samples of bog iron ores, were collected at different sites in the Polish Lowlands: Kolechowice (KOL), Biadaszki (BD), Strzyżew (ST) and Dębe Małe (DM). They represent different bog iron ore types which, in spite of having diversified structures, mineral composition and, subsequently, physical and chemical properties, revealed good sorption affinities for trace elements in previous work (Rzepa et al. 2009). In batch experiments the influence of various factors on adsorption were studied, including initial As concentrations, initial pH values and competitive adsorption of As(III) and As(V). The effect of initial As concentrations was studied in the range of 0.01–20 mM As(III) or As(V) at pH 7.5. The influence of pH was evaluated by the adsorption of 5 mM As solution in the pH range of 2–12. The experiment of competitive adsorption of arsenite and arsenate was performed for various proportion of As(III) to As(V) in the range of initial concentrations 0.025–20 mM at pH 7.5. The bonding strength of As with bog iron ore surface was estimated on the basis of three-step desorption experiments, which were conducted for the samples previously treated with As(III) or As(V) at pH 7.5 and at constant 20 mM initial concentration of arsenic. Arsenic concentrations in filtered (filter with a 0.22 μm pore size) solutions after all the experiments were analyzed using AAS and UV-Vis spectrophotometry. The results showed that arsenic sorption depends on its oxidation state. All the bog iron ores bound more As(III) than As(V). The highest amount of As(III) was sorbed by ST sample (458 mmol/kg), lower by KOL (430 mmol/kg) and DM (427 mmol/kg), and the lowest by BD (333 mmol/kg). However, in the case of As(V), the order was different: the highest amount of As was sorbed by BD sample (264 mmol/kg), lower by ST (218 mmol/kg), and the lowest by DM (163 mmol/kg) and KOL (158 mmol/kg). The highest uptake (80–95%) of As(III) was noted at lower initial concentrations, while the highest uptake (60–70%) of As(V) was observed at higher initial concentrations. As(III) sorption effectiveness was >80% throughout the pH range of 4 to 9 and was almost independent on pH in that range. In contrast, the As(V) sorption was higher at slightly acidic pH and significantly decreased in alkaline conditions. At pH around 3, sorption efficiency of both As(III) and As(V) decreased, which is likely due to the increased solubility of iron oxyhydroxides (Zeng, 2004). The results of competitive sorption experiments revealed that at low concentrations of both As species reduction of sorption efficiency of As(III) occurred. Sorption of As(V) was also affected, but only if amount of As(III) was higher than As(V). On the contrary, at high As(V) and As(III) concentrations, As(V) did not influence As(III) sorption, but As(III) substantially increased sorption of As(V). Desorption of arsenic by foreign ligands resulted in extraction of more than 70% of absorbed As(III) and As(V). In the absence of the exchange ligand, i.e., in deionized water, desorption of As(V) and As(III) was considerably lower, but noticeable. This study shows that bog iron ores are very good arsenic sorbents. However, the extent of As removal seems to be affected by various factors including As species and the composition of the ores themselves. As(V) is immobilized less effectively than As(III), and the process is influenced by pH values. It is believed, that the uptake of As by bog ores is controlled primarily by iron oxyhydroxides, as main components of these rocks, but mechanisms predominant in As(III) and As(V) adsorption are different and affected by presence of e.g. phosphate and silicate ions (Ociński et al. 2011). There are no simple correlations between mineralogy and sorption capacity. Due to the variability in chemical and mineral composition of different types of bog iron ores, various levels of arsenic removal can be obtained. Such properties of the ores, combined with their ubiquity in many near-surface environments may be regarded as an incentive for the environmental protection practice.

15

Skład mineralny i właściwości tekstualne zeolitów z metakaolinu

Grela A., Bajda T., Mikuła J.

Przemysł Chemiczny

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2015

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T. 94, nr 4

619-622

PL

Przedstawiono wyniki badań doświadczalnych niskotemperaturowej alkalicznej aktywacji metakaolinu. Dla metakaolinu (M) oraz otrzymanego przez syntezę niskotemperaturową materiału zeolitowego (MN) przedstawiono wyniki analiz SEM/EDS, wyniki oznaczenia gęstości 2,62 g/cm³ (M) i 2,16 g/cm³ (MN); wyniki badań porozymetrycznych m.in. metodą BET 8,36 ± 0,15 m²/g (M) i 273,63 ± 2,98 m²/g (MN); wyniki analizy termicznej (TG, DSC) 4% (M) i 19,4% (MN) oraz rentgenowskiej analizy dyfrakcyjnej, w której wykazano obecność Zeolitu X (Na), Zeolitu A (Na) i Halloysite-10A. Oznaczono też pojemność kationowymienną (CEC) 6,0 ± 0,8 meq/100 g (M) i 297,3 ± 8,4 meq/100 g (MN). Modyfikacja metakaolinu pozwoliła na znaczne zwiększenie powierzchni właściwej oraz wzrost CEC.

EN

Metakaolin was treated with alk. agents at low temp. and studied for morphol., d., sp. surface, pore and micropore vols., thermal decompn. and cation-exchange capacity. The treatment resulted in decrease in d., pore diam. and thermal stability as well as in an increase in sp. surface, pore vol. and micropore surface.

16

Structural and vibrational behaviour of pyromorphite-vanadinite solid solution series

Solecka U., Bajda T., Topolska J., Manecki M.

Geology, Geophysics and Environment

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2015

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Vol. 41, no. 1

135--136

EN

Pyromorphite Pb5(PO4)3Cl and vanadinite Pb5(VO4)3Cl belong to the apatite supergroup. They are secondary minerals formed in the oxidation zones of lead ore deposits. Both crystallize in hexagonal symmetry with the space group P63/m (Dong et al. 2002). The crystal structure of these two minerals allows to accommodate both metal cations and anionic complexes. It is the reason, why pyromorphite and vanadinite forms solid solution series. Isovalent replacement of P with V is one of the most common anionic substitution. Lead apatites are one of the least soluble along apatites group minerals and characterized by high thermal stability (Dong et al. 2002, Flis et al. 2011). Characteristic properties of apatite structure cause that these minerals are successfully used in many fields, especially for the immobilization of toxic waste and lead-contaminated soil (Ma et al. 1993, Chen et al. 1997, Dong et al. 2002, Kim et al. 2005). So far, pyromorphite and mimetite are the most known and used for the immobilization of lead. Pyromorphite and mimetite are isostructural with vanadinite, therefore it has been predicted that this mineral is also important for the environment. Accordingly, the aim of this study was to characterize of the pyromorphite-vanadinite solid solution series. This research presents systematic changes in the structure of these minerals. Pure pyromorphite and vanadinite and minerals with intermediate compositions Pb5(TO4)3Cl, where T = P + V, of various P/V ratios were synthesized from aqueous solutions at 298 K and pH = 3.5. Synthetic solids were analyzed by X-Ray diffraction (XRD), infrared absorption spectroscopy (FTIR) and Raman spectroscopy. Based on the X-Ray analysis, it was found that synthetic precipitates represent homogeneous phases of pyromorphite and vanadinite, which have intermediate chemical composition. Diffraction peaks of pyromorphite-vanadinite solid solution series were shifted due to replacement of PO4 by VO4. Replacement of PO4 by VO4 anions is causing changes in the structure of apatite and hence these shifts. Unit cell parameters of studied solid solutions show a linear variation. In the FTIR and Raman spectra of pyromorphite-vanadinite solid solutions series, the bands which are characteristic for vibrations of P-O bonds of the PO4 tetrahedra as well as vibrations of V-O bonds of the VO4 tetrahedra appeared. Analysis of Mid-IR spectra and Raman spectra also allowed observing correlation between the band positions and the extent of the anionic substitution among the studied series. The structure of pyromorphite and vanadinite is generally similar, although the two minerals vary in chemical composition. This variability results probably from the properties of individual ions.

17

Structural and Raman spectroscopy studies of schultenite - phosphoschultenite isomorphic series

Młynarska M., Manecki M., Bajda T.

Geology, Geophysics and Environment

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2014

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Vol. 40, no. 1

110--111

EN

In many countries, there is a problem of lead and arsenic soils contamination. Lead can be immobilized using phosphate amendments (Cao et al. 2003). This technique, however, results sometimes in arsenic migration. Mineral phases, which can precipitate in this conditions include schultenite PbHAsO4 and phosphoschultenite PbHPO4. Only recently it has been experimentally shown that these minerals can form a continuous solid solution series in Earth surface environments (Zembal 2012). Therefore, it is important to extend our knowledge on the properties of schultenitephos-phoschultenite solid solution series in order to solve certain environmental problems. For the first time, Raman spectroscopy was used to characterize schultenite, phosphoschultenite and their solid solutions. The main objective of this research is the identification and interpretation of systematic changes in the results of X-ray diffractometry and Raman spectroscopy applied to synthetic schultenites with various P to As ratio. Six samples were synthesized from aqueous solutions at ambient conditions. The ratio of P/(P + As) varied from 0 to 1 by 0.2 (Zembal 2012). Schultenite PbHAsO4 and phosphoschultenite PbHPO4 belong to monoclinic crystallographic system. The standard model of the P2/c symmetric group was used in the calculation of unit cell parameters. The results show systematic increase in unit cell parameters with substitution of P for As in the series: parameter a from 4,6737 to 4,8588, parameter b from 6,6381 to 6,7528 and parameter c from 5,7617 to 5,8495. The Raman spectra have also shown systematic variation in stretching and bending vibrations in the series. The ν1 stretching As-O band shifts from 463 cm-1 in schultenite PbHAsO4 to 469 cm-1 in P-substituted schultenite while ν 4 bending As-O band shifts form 824 cm-1 to 841 cm-1. Similar is observed in phosphoschultenite: the v1 stretching P-O band shifts from 555 cm-1 to 569 cm-1 and v bending P-O band shifts form 905 cm-1 to 940 cm-1 with increasing P content Observed shifts in position of Raman effects correlate linearly with As-P substitution: the bands originating from vibration modes shift to higher wave numbers with the substitution of P for As from schultenite PbHAsO4 towards phosphoschultenite PbHPO4. This can be explained by the fact that atomic mass of As is higher than that of P and that As-O bonds are longer than P-O bonds. The results extend our knowledge about schultenite-phosphoschultenite isomorphic series. Systematic shifts of Raman effects correlate strongly with chemical composition of analyzed phases. This is associated with systematic linear variation in the height (between 4,403 and 411 units for As-0 ν 4 bending band and between 825 and 70 units for P-0 v4 bending band) and area under certain peaks on Raman spectra (between 71,423 and 30,805 units for As-O ν 4 bending band and between 28,982 and 2,095 units for P-O ν 4 bending band). Current findings suggest that it is possible to estimate the overall P/(P+As) ratio in mineral samples by precise determination of the position and area under the respective Raman spectra and comparison with standard measurements.

18

Quantitative determination of ammonium salts in organo-zeolites by infrared spectroscopy

Szala B., Bajda T., Matusik J.

Geology, Geophysics and Environment

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2014

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Vol. 40, no. 1

131--132

EN

In recent years, the feasibility of using fly ash from the combustion of coal for the synthesis of zeolites has been studied (Belviso et al. 2010, Derkowski et al. 2010). One of the many uses of zeolites is to leverage their properties to act as organic sorbents (Bowman 2003). Unfortunately, the sorption process of organic substances on zeolites is hampered by the negatively-charged surface of the crystallites (Jashua & Bowman 2009). In order to increase the chemical affinity of the zeolite's surface to the organic molecules, its modification by organic surfactants is necessary. This leads to the formation of an organo-mineral complex with improved sorption properties. It has been found that organo-zeolites may be used to remove volatile compounds in a pure form, and those which occur in nature as impurities of air, water and soil (Damjanovic et al. 2010, Vidal et al. 2012). Therefore, it seems reasonable to search for an organo-zeolite sorbent which is cheap, efficient and environmentally-friendly (Apreutesei et al. 2008). The zeolites modification takes place only on the outer surface of the crystallites as the ammonium salts' molecules are too large to enter the zeolite's channels. Therefore, external cation exchange capacity (ECEC) is an important property in the synthesis of organo-zeolites. The type of surfactant introduced and its amount, often given by ECEC values, is crucial-subsequently leading to the formation of materials differing in sorption properties. Thus, it is essential to determine the effectiveness of modification by examining the amount of surfactant adsorbed on zeolites' surface. In the experiments, a Na-P1 zeolite synthesized from fly ash remaining after coal combustion and a natural Ukrainian zeolite were transformed into organo-zeolites. This involved the replacement of original exchangeable cations (K+, Na+, Ca2+, Mg2+) by organic cations from the following salts: hexadecyltrimethylammonium bromide (HDTMA) and octadecyltrimethylammonium bromide (ODTMA) in amounts equal to 0.25, 0.50, 0.75 and 1.00 of ECEC. ECEC for synthetic zeolite Na-P1 was determined, and it was 24.4 meq/100 g, which corresponds to a single layer (1.0). The aim of this study was to use the infrared spectroscopy (FTIR) to determine the quantity of the surfactant adsorbed on the crystallites surface. The FTIR spectra were collected by a Thermo Scientific Nicolet 7600 spectrometer using the DRIFT technique. The CHN analysis was used to investigate the modification efficiency through quantification of the attached surfactant. The normalized intensity of selected bands attributed to C-H stretching vibrations in the 3,000-2,800 cm-1 region was compared with CHN results. The results revealed a high correlation (R2 > 0.99) between spectroscopic and chemical analyses. The band intensities compared with the efficiency of modification enabled to obtain appropriate calibration curves. This proved that FTIR could be used for a fast determination of the surfactants amount in the obtained organo-zeolites.

19

Optimization of synthesis conditions of pyromorphite-vanadinite and mimetite-vanadinite solid solution series

Janicka U., Bajda T., Topolska J., Manecki M.

Geology, Geophysics and Environment

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2014

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Vol. 40, no. 1

88

EN

Minerals: pyromorphite Pb5(PO4)3Cl, mimetite Pb5(As04)3Cl and vanadinite Pb5(VO4)3Cl belong to the apatite supergroup. Commonly they form in hypergenic conditions. They are best known from the oxidation zones of lead ore deposits. Natural pyromorphite usually contains admixture of arse-nates or vanadates, whereas mimetite or vanadinite contain admixtures of phosphates. Solid solutions of the pyromorphite-mimetite series are well known, while the knowledge about anionie substitutions in vanadinite is incomplete. Therefore, the aim of this study was to find optimal conditions for the synthesis of pyromorphite-vanadinte and mimetite-vanadinite solid solution series. This research will allow to check the range of possible anionie substitutions, formation conditions such as pH, temperature and in, turn, to obtain better knowledge about the properties of these minerals. Pyromorphite, mimetite, vanadinite and pyromorphite-vanadinite and mimetite-vanadinite solid solutions series were synthesized from aqueous solutions. Solutions containing Pb2+, PO43-, AsO43-, VO3- , VO43- and Cl- ions in stoichiometric molar proportions were dropwise mixing. This method of synthesis allows controlling the stoichiometry of the chemical composition of synthetic precipitates. Synthesis reactions were carried out at various pH and at different temperatures (range from 25°C to 85°C). After the synthesis, suspensions were left for two weeks for aging. Then the suspensions were filtered using a Biichner funnel. The precipitates were washed with double-distilled water and acetone, and then dried. Synthetic precipitates were analyzed using various analytical techniques including X-Ray diffraction (XRD), Scanning electron microscopy coupled with Energy Dispersive Spectroscopy (SEM/EDS), Infrared absorption spectroscopy (FTIR) and Raman spectroscopy. Results of XRD, SEM/EDS, FTIR and Raman spectroscopy analyzes of studied samples showed that temperature 25°C and pH = 3.5 are optimal conditions to synthesize pyromorphite-vanadinite and mimetite-vanadinite solid solution series. Chervetite Pb2V2O7 was formed together with studied phases at lower pH values (1.7, 2.2), or higher temperatures (75°C, 85°C). At pH = 11.5, minerals with hydroxyl groups were formed. It has been observed that the formation of pyromorphite-vanadinite and mimetite-vanadinite solid solution series mainly depends on the pH values. The temperature is less important.

20

Changes in physical structure during calcination of carbonate rocks

Turek P., Hycnar E., Bajda T.

Geology, Geophysics and Environment

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2014

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Vol. 40, no. 1

133--134

EN

Limestone and other carbonate rocks are commonly used as sorbents for removing sulfur oxides from coal combustion flue gases. The process is based on chemical reaction between calcium oxide CaO and sulfur dioxide SO2, which results in formation of anhydrite CaSO4. CaO required for the reaction is produced by thermal dissociation of calcite CaCO3 which is the major constituent of each limestone. Calcite during calcination is decarbonized according to the reaction CaCO3 → CaO + CO2. The quality of such sorbent is usually being related to its total uptake of sulfur dioxide, which is frequently considered to depend mainly on chemical composition of the sorbent, especially CaCO3 content. However, there are premises that the rate of desulphurization of contaminated gases depends more on the structure of the products of limestone calcination than on CaCO3 content. Exceptionally significant is the surface area of CaO which results from its high porosity. The formation of such structure can be affected by several factors among which the structure of the raw material, its porosity and pore distribution along with crystallinity and the size of crystals are considered to be the most important issues. The current study demonstrates that the size of calcite crystals plays a key role in developing high porosity during limestone calcination in spite of calcium carbonate content in raw material. Four samples of different carbonate rocks were investigated: 1.crystalline limestone with well-developed calcite crystals of size 1-2 mm; 98.75 wt. % CaCO3; 2. micrite limestone with calcite crystals of size not exceeding 2 (im and 94.08 wt. % CaCO3; 3. limestone with calcite crystals of size up to 50 (μm dispersed in a micrite background; 94.75 wt. % CaCO3; 4. marble with crystals up to 1 mm; 96.08 wt. % CaCO3. The samples were ground to 0.125-0.250 mm particle size and calcined in the fixed bed at 850°C for 1 hour. The observation for differences in morphology of raw and calcined samples were conducted using Scanning Electron Microscopy (SEM). The particles and pore size distribution were characterized by BET analysis using low-temperature nitrogen adsorption technique. The content of CaCO3 in raw samples was calculated using total Ca content which was determined by titration with EDTA after digestion of samples with hot hydrochloric acid. SEM images revealed a regular system of cracks in the sample 1. The whole surface of calcite grains fractured and became very rough and porous. Sample 2, which was cryptocrystalline, did not show such behavior. Cracks and fractures did not occur, but under large magnification a slight porosity could be observed. Large crystals of the third sample cracked in a similar way to sample 1. Noteworthy is also the fact of creating little voids on the grain contact. Calcite crystals in sample 4 fractured along wide cracks into large fragments. Smaller clefts also occurred but they created irregular pattern, in contrast to sample 1. BET analysis confirmed foregoing SEM data. The calcination process increased the porosity and surface area of the investigated samples which was more evident with respect to more crystalline samples. Moreover, the pore distribution changed significantly. Calcination was followed by formation of the new porosity of samples, especially in mesoporous and macroporous range. Cracks in coarse calcite crystals enhance calcination by creating fast diffusion ways for CO2 escape. They could play similar role in sorption of SO2, hence the structure of raw sorbent becomes more significant issue with respect to flue gases desulphurization problem.