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Jacek Góralski, Bożena Szczepaniak, Jacek Grams, Waldemar Maniukiewicz and Tadeusz Paryjczak

Characteristic of physicochemical properties of Pd/MgO catalysts used in the hydrodechlorination process with CCI4

The aim of this paper was to investigate the physicochemical properties of palladium catalyst containing basic support MgO which was used in hydrodechlorination reaction with carbon tetrachloride. In order to characterize the investigated sample the catalyst was put to tests of XRD, TOF - SIMS, TG-DTA-MS and TPRH2 measurements, activity tests were also performed. The XRD and TPR results demonstrated the presence of PdOxCly species whose decomposition takes place above 700°C. The calcination of the Pd/MgO catalyst at 700°C resulted in the transformation of PdOxCly to PdO.

Open access

Andrzej Żarczyński, Marcin Zaborowski, Tadeusz Paryjczak, Zbigniew Gorzka and Marek Kaźmierczak

Application of catalysts in the treatment of selected waste chloroorganic compounds

Tetrachloromethane (TCM) and 1,1,2,2-tetrachloroethane (TChE) were oxidized in the temperature range from 300 to 600°C and at contact time of 0.36 s. The following catalysts were applied during the process: the granular one - platinum (0.12%) at the TiO2-SiO2 carrier, platinum ZChO-80 (0.15%) at γ-Al2O3 carrier, palladium (1%) at γ-Al2O3 carrier and monolithic platinum-rhodium catalyst (Pt - 0.09% and Rh - 0.04%) at the cordierite carrier.

The substrates were oxidized in the presence of the above mentioned catalysts with various efficiencies depending on the molecular structure and the type of the catalyst. Palladium contact appeared to be the most active among the others. In the presence of this catalyst, total oxidation of TCM and TChE proceeded at the temperature of 425 and 500°C, respectively. The content of PCDD/Fs in gaseous products obtained during the oxidation of both substrates, was significantly lower than the admissible value of the toxicity equivalent (0.1 ng TEQ/m3).

Open access

Małgorzata Szynkowska, Ewa Leśniewska, Aleksandra Pawlaczyk, Jacek Rogowski and Tadeusz Paryjczak

Application of the TOF-SIMS and SEM-EDS methods to assess the influence of dusting from a phosphate waste deposal place based on hair analysis

In this work, scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDS) and the time-of-flight secondary ion mass spectrometry (TOF-SIMS) were used to study the particles present on the hair surface of the inhabitants of Wislinka (people environmentally exposed due to the closeness of a dump) in order to obtain the information about the possible influence of dusting from a phosphate waste deposal place. Additionally, the morphology and the composition of fresh phosphogypsum were analyzed. Waste phosphogypsum is formed in the process of a wet phosphoric acid production and there is still a problem with its storage. A thorough understanding of the composition and chemistry of phosphogypsum seems to be necessary to evaluate its environmental impact comprehensively. The results obtained from these two techniques turned out to be complementary and revealed the information expected.

Open access

Jacek Grams, Jacek Góralski, Joanna Kleczewska, Bożena Szczepaniak and Tadeusz Paryjczak

ToF-SIMS studies of the surface of Pd/ZrO2-TiO2 catalyst used in the hydrodechlorination process

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used in order to obtain the information about the surface composition of Pd/ZrO2-TiO2 catalyst and to estimate the changes in the concentration of particular components on its surface during the hydrodechlorination of CCl4. The results demonstrated that the hydrodechlorination process led to the increase in the concentration of chlorine and the drop in the amount of surface accessible palladium, while the quantity of Pd-Cl bounds did not change considerably. It suggested that the presence of ZrO2 protected the surface of the studied catalyst against the formation of PdCl2.

Open access

Małgorzata Szynkowska, Ewa Leśniewska, Aleksandra Pawlaczyk, Jadwiga Albińska, Katarzyna Bawolak and Tadeusz Paryjczak

The mercury analysis in airborne particles emitted from coal-combustion processes

Determination of trace elements in combusted materials has always been an interesting field of environmental studies. Particulate matter, in particular, is a serious problem which, can lead to air pollution especially by heavy metals emissions in urban and industrial areas. There is a considerable concern about the elevated level of mercury released during combustion and the proportion of anthropogenic mercury in the environment. Nowadays, small-scale installations have been identified as a significant source-pathway for mercury pollution, particularly those that use coal. A total amount of mercury was determined using Mercury Analyzer. The investigated material consists of bottom ash, fly ash, slag, soot or dust. The obtained results varied according to the type of the material and plant. The developed methodology was checked by carrying out the analysis of certificate material of Soil NCS ZC 73001 and the reference material of Soil-7.