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Potencjał materiałów pochodzenia naturalnego zawierających mangan w katalitycznym oczyszczaniu gazów odlotowych z instalacji kwasu azotowego

Inger Marek, Rajewski Jakub, Kowalik Wojciech, Hubicki Zbigniew, Bąk Justyna, Wójcik Dominika

Przemysł Chemiczny

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2023

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T. 102, nr 12

1334--1341

PL

W pracy zbadano możliwość zastosowania dwóch naturalnych materiałów zawierających tlenek manganu, Pyrolox® iPurolite MZ-10® , jako układu wyjściowego przy opracowaniu nowego katalizatora wtechnologii oczyszczania z N₂O lub NOₓ strumienia gazów resztkowych z instalacji kwasu azotowego. Obie badane próbki poddano charakterystyce fizyczno-chemicznej. Wykonane pomiary wykazały, że jedynie Pyrolox® wykazuje aktywność w reakcji rozkładu N₂O. Uzyskano konwersję N₂O wynoszącą 31 i 70% wtemp. odpowiednio 480 i 495°C. Po dodaniu do strumienia gazów resztkowych amoniaku stwierdzono aktywność obu badanych materiałów w reakcji redukcji NOₓ. Wtym przypadku stwierdzono również znaczące zwiększenie stężenia N₂O w strumieniu gazów poreakcyjnych, co powoduje znikomą przydatność tych materiałów jako katalizatorów selektywnej redukcji NOₓ.

EN

A lab. flow reactor with a fixed bed of catalyst (Pyrolox® or Purolite MZ-10®) was fed with a stream of tail gases from the HNO₃ plant. The process of N₂O decompn. and NOₓ redn. was studied at temp. of 249-458°C. Only Pyrolox® was active in the N₂O decompn. reaction with conversions of 31 and 70% at 480 and 495°C, resp. After adding NH₃ to the tail gas stream, both tested materials were found to be active in the NOₓ redn. reaction. However, in this process, a significant increase in the N₂O concn. was found in the post-reaction gas stream, which makes these materials of little use as a catalyst for selective NOₓ redn. Pyrolox® and Purolite MZ-10® were analyzed for the sp. surface area, pore size as well as chem. compn.

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Application of Pyrolox sorbent for vanadium(V) ions removal

Wójcik Grzegorz, Hubicki Zbigniew

Physicochemical Problems of Mineral Processing

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2022

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Vol. 58, iss. 2

art. no. 147974

EN

The sorption of vanadium(V) ions from acidic solutions using the Pyrolox sorbent was studied at varying ions concentrations, pH, contact time and temperature. The investigated ions were determined by means of graphite-furnace atomic absorption spectrometry (GF-AAS). The sorption capacity of vanadium(V) ions was examined in the pH range 2-10. The adsorption capacities of vanadium(V) ions depend on the pH values. Therefore, the initial pH 2 of vanadium(V) results in the highest adsorption capacities. The sorption vanadium(V) kinetics was investigated. The experimental data were analyzed using the pseudo-first-order, pseudo-second-order forms, Elovich, and intra-particle diffusion models. The kinetics of vanadium(V) sorption is described by the pseudo-first-order in the best way. The results indicate the endothermic process of V(V) ions sorption. The presented results of vanadium ions recovery from the solutions obtained as a result of spent catalysts leaching indicate the possibility of vanadium recovery.

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Electrokinetic properties of silica-titania mixed oxide particles dispersed in aqueous solution of C.I. Direct Yellow 142 dye – effects of surfactant and electrolyte presence

Chibowski Stanisław, Wiśniewska Małgorzata, Wawrzkiewicz Monika, Hubicki Zbigniew, Goncharuk Olena

Physicochemical Problems of Mineral Processing

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2020

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Vol. 56, iss. 6

6--13

EN

The mixed SiO2-TiO2 oxide obtained by the pyrogenic method with the silica:titanium percentage ratio equal to 20:80 (ST80) was used in the experiments. The influence of azo dye C.I. Direct Yellow 142 (DY) adsorption at the mixed oxide-solution interface on the electrokinetic properties of solid particles was studied. To determine solid surface charge density and zeta potential of examined suspensions the potentiometric titration and Doppler laser electrophoresis techniques were applied. The changes in structure of electrical double layer formed on the mixed oxide surface in the dye presence were specified as a function of DY concentration, inorganic salt addition and surfactant introduction. The effects of surfactant type and its concentration were determined. Three surfactants of different ionic character (anionic SDS, cationic CTAB and nonionic Triton X-100) were used in measurements. The obtained electrokinetic characteristics of ST80 mixed oxide dispersed in aqueous solutions with various adsorbate compositions is essential for such suspensions stability.

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Removal of acid, direct and reactive dyes on thepolyacrylic anion exchanger

Polska-Adach Ewelina, Wawrzkiewicz Monika, Hubicki Zbigniew

Physicochemical Problems of Mineral Processing

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2019

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Vol. 55, iss. 6

1496--1508

EN

In the present studythe polyacrylic anion exchanger Amberlite IRA 478 (IRA 478) was used forremoval of textile dyes such as C.I. Acid Red 18 (AR18), C.I. Reactive Blue 21 (RB21) and C.I. Direct Yellow 142 (DY142) from aqueous solutions. Sorption of the above-mentioned dyes was carried out by the static and dynamic methods. The obtained results were analyzed by determining the adsorption isothermparameters using the Langmuir and Freundlichmodels. Kinetic parameters of dyessorption were calculated from the pseudo-first order, pseudo-second order and intraparticle diffusion models. The monolayer sorption capacities of IRA 478 determined from the Langmuir isotherm were found to be 1098.5 mg/g for AR18 (R2=0.994), 46.8 mg/g for DY142 (R2=0.820) and 23.5 mg/g for RB21 (R2=0.987).Kinetic studies revealed that effectiveness of AR18, DY142 and RB21 uptakeincreases with increasing phase contact time and initial dyesconcentration.The kinetics of the dyessorption process on the anion exchanger is best described by the pseudo-second order model (PSO) due to the high values of the determination coefficients R2 (linearity condition of the plot t/qt vs.t). The rate constantsof the pseudo-second order kinetics k2are reduced from 0.1001 to 0.0008 g/mg·min for AR18, from 0.0147 to 0.0112 g/mg·min for DY142 and 0.0489 to 0.0072 g/mg·min for RB21 with an increase of initial concentration of dyes.The presence of salts and surfactants had an impact on the retention of direct and reactive dyes.