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Adsorption of 4-aminopyrimidine at the R-AgLAFE/chlorate(VII) interface. Comparison of the adsorption properties of various water activity as well as different surfactants

Martyna Marlena, Pawlak Alicja, Grochowski Mariusz, Bazan-Woźniak Aleksandra, Pietrzak Robert, Nosal-Wiercińska Agnieszka

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 4

art. no. 170204

EN

The results of 4-aminopyrimidine (4-APM) impact studies on the double layer parameters at the R-AgLAFE/ chlorates(VII) interface in the solutions with different water activity as well as different properties of the mixed adsorption layer of 4-aminopirimidine - sodium 1-decanesulfonate (SDS) and 4- aminopyrimidine - hexadecyltrimethylammonium bromide (CTAB) at the electrode/solution interface are discussed.The differential capacity of the double layer (Cd) at the R-AgLAFE/ basic solution interface was measured using the electrochemical impedance spectroscopy. The zero charge potential (Ez) was determined using a streaming electrode, while the surface tension at the zero charge potential (Yz) was measured using the largest pressure method inside the mercury drop. It was proved that both the 4-aminopirymidine concentration and water activity have an essential effect on the doublelayer parameters on the R-AgLAFE/ chlorates(VII) interface. In the studied systems: 4-APM - SDS and 4-APM - CTAB, 4-aminopyrimidine dominance was observed.

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Grzyby i odpady grzybowe jako nowe prekursory do otrzymywania adsorbentów węglowych

Koźlarek Natalia, Bazan-Woźniak Aleksandra, Pietrzak Robert

Wiadomości Chemiczne

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2022

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[Z] 76, 3-4

221--236

EN

Undesirable changes in the bacteriological, physical and chemical properties of water are a consequence of introduction of excessive amounts of inorganic and organic materials to it. These pollutants limit or prevent the use of water for drinking, food production and household purposes. The greatest amounts of pollutants enter the watersystem with sewage. Also the pesticides,surfactants, organic dyes, artificial fertilizers along with municipal and industrial waste can easily enter water system and threaten the organisms living there. Another, equally important problem is the pollution of atmospheric air. Emission of solid liquid or gas pollutants to the atmosphere has been proved to have significant impact on human health, climate and nature. That is why the search for new and more effective technologies for the environment purification is a continuous challenge. Recently, increasingly often carbon materials are used as effective adsorbents of pollutants from liquid and gas phases.

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Membranes obtained on the basis of cellulose acetate and their use in removal of phenol from liquid phase

Przybył Joanna, Bazan-Wozniak Aleksandra, Nosal-Wiercinska Agnieszka, Pietrzak Robert

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 144174

EN

The membranes based on cellulose acetate (CA) were obtained by the method of phase inversion and used for removal of phenol (in concentrations of 15 and 25 mg/L) from liquid phase. To differentiate the hydrophilic properties of the membrane surfaces, different amounts of cellulose acetate (14 and 18 wt. %) and polyvinylpyrrolidone as a pore-generating agent (PVP, 1, 2, 3 or 4 wt. %) were used. The membranes were characterised by determination of their porosity, equilibrium water content, wetting angle and content of surface oxygen functional groups. After the application of membranes to phenol removal, the following parameters characterising the process were determined: permeability, membrane resistance, coke resistances, pore resistances, total filtration resistance and flux recovery ratio. The membranes were found to show higher effectiveness in phenol removal from a solution of the initial concentration 15 mg/L, and more effective were the membranes with higher contents of cellulose acetate. On the surface of the membranes the oxygen functional groups of acidic nature are dominant, both before and after filtration. The membranes of higher contents of cellulose acetate show higher resistances.

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Synthesis of new carbon-nitrogen composites based on waste sweet drinks

Kaźmierczak-Raźna Justyna, Pietrzak Robert, Nowicki Piotr

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1366--1374

EN

The materials under investigation were new carbon-nitrogen composites obtained via pyrolysis and CO2 activation of sweet drinks destined for utilization. Waste Pepsi Cola® has been examined as an alternative and renewable carbon source for composite materials. Nitrogen was introduced into the Pepsi Cola® solution via the addition of guanidine carbonate, before the pyrolysis process. The physicochemical properties of the materials studied were characterized by low- temperature nitrogen adsorption (using BET and BJH methods), elemental analysis, FTIR spectroscopy, scanning electron microscopy (SEM) as well as determination of pHPZC and the number of surface functional groups. Additionally, thermal properties of the samples were investigated by thermogravimetric analysis (TG) and differential thermogravimetry (DTG). The final products were new carbon-nitrogen composites characterized by a very high content of nitrogen (11.2 - 21.6 wt.%) as well as relatively low surface area and pore volume reaching 198 m2/g and 0.16 cm3/g, respectively. Results of FT-IR study and Boehm titration indicated that the composites surface has clearly basic character, which was confirmed by pHpzc values above 8.0.

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Activated bio-carbons prepared by physical activation of residues after supercritical extractionof raw plants

Bazan-Woźniak Aleksandra, Pietrzak Robert

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1357--1365

EN

A series of activated bio-carbons has been obtained by physical activation of residues after supercritical extraction of blackberries, raspberries and blackcurrants. The effects of different temperatures of activation and different starting materials on the physicochemical and sorption properties of the bio-carbon samples obtained were evaluated. The physicochemical properties of the activated bio-carbons were characterized by elementary analysis, low-temperature nitrogen sorption and Boehm titration. All materials were tested as adsorbents of pollutants from gas (nitrogen dioxide) and liquid (iodine, methylene blue) phase. The sorption properties of the activated bio-carbons were tested at 23°C. The materials obtained were activated bio-carbons of surface area ranging between 303 and 442 m2/g and showing basic character of the surface. The content of elemental carbon in the obtained samples was in the range of 73.4-82.1 wt. %. The maximum adsorption capacities of the materials towards nitrogen dioxide were 65 mg/g, methylene blue -207 mg/g, and iodine 1001 mg/g. According to the adsorption tests towards nitrogen dioxide, the sorption capacities of the adsorbents studied were increased if a mixture of nitrogen dioxide and air had a humidity of 70 %. The mechanism of methylene blue adsorption involved the formation of adsorptive multilayer. The most effective adsorbent of organic and inorganic pollutants proved to be the activated bio-carbon obtained from the residues after supercritical extraction of blackcurrants.