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1

Badania adsorpcji-desorpcji herbicydów na granulowanym węglu aktywnym

Białek A., Kuśmierek K., Świątkowski A.

Przemysł Chemiczny

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2016

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T. 95, nr 9

1842--1846

PL

Zbadano kinetykę i adsorpcję równowagową kwasu 2,4-dichlorofenoksyoctowego (2,4-D) oraz kwasu 2-metylo-4-chlorofenoksyoctowego (MCPA) z roztworów wodnych na granulowanym węglu aktywnym WG-12. Badania kinetyczne pokazały, że MCPA adsorbował się szybciej niż 2,4-D. Kinetyka przebiegała zgodnie z równaniem pseudo II rzędu. Analizowano również wielkości adsorpcji w funkcji stężenia równowagowego. Uzyskane dane doświadczalne były dobrze opisane za pomocą równań izoterm Langmuira i Freundlicha. Zbadano również desorpcję 2,4-D i MCPA z użyciem acetonitrylu, metanolu i roztworów wodorotlenku sodu. Najlepszą wydajność procesu zaobserwowano w przypadku użycia acetonitrylu (po 8 h desorpcji uległo 29,6% 2,4-D i 27,0% MCPA).

EN

2,4-Dichlorophenoxyacetic (2,4-D) and 2-methyl-4-chlorophenoxyacetic (MCPA) acids were adsorbed from aq. solns. onto WG-12 granular activated C to study the adsorption kinetics and equils. MCPA was adsorbed faster than 2,4-D. The kinetics was fitted well to the pseudo-second order model. The expt. isotherms were well described by the Langmuir and Freundlich equations. The desorption of 2,4-D and MCPA with MeCN, MeOH and NaOH solns. was also studied. The best desorption efficiency was obsd. when MeCN was used.

2

Fotokatalityczna degradacja herbicydów : nowe katalizatory na bazie TiO2

Ożóg S.

Wiadomości Chemiczne

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2015

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[Z] 69, 7-8

606--616

EN

Over the past few decades a rapid increase in standard of living is observed. Rapid urbanization and development of new technologies, which are focused on the needs of a modern society, influence negatively the environment. The present policy of sustainable development is focused on the principles of rational use of scarce resources and raw materials. New technologies should comply with a number of requirements: efficiency, low costs and a low impact on the environment. Photocatalytic processes are the answer for these requirements. Photocatalysis can be used in many aspects of everyday life, offering self-cleaning surfaces, photo-drugs (e.g. for photodynamic therapy) and even photovoltaic devices. Photocatalytic degradation of pollutants in the presence of inorganic photocatalysts (e.g. TiO2 or ZnO) is one of the available methods of removing impurities from aqueous and gaseous phases. The main advantage of this process is the lack of wastes and formation of carbon dioxide, water and simple inorganic ions as end- -products. The aim of our work was to develop new TiO2-based photocatalysts doped with tungsten and molybdenum oxides. A series of materials with different content of the dopants, calcined at various temperatures, was prepared. The photocatalytic activity of the materials was determined following the degradation of two model herbicides: 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). These compounds are used for the control of weed growth on crop plantations, but in a high dosage they can lead to destruction of the plants. They are readily soluble in water, therefore their use is simple, but brings a great risk to aquatic organisms and people. Photocatalytic degradation of herbicides is the main goal of the 4G-PHOTOCAT project. The efforts are directed towards development of a low-cost photocatalytic paint, that could be used in reactors for groundwater purification. The active ingredient of the paint is a composite material based on TiO2 modified with other metal oxides.

3

Technological aspects of the synthesis of 2,4-dichlorophenol

Białek A., Moszczyński W.

Polish Journal of Chemical Technology

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2009

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Vol. 11, nr 2

21-30

EN

The main factors influencing the selectivity of chlorophenols synthesis were described. The loss of raw materials and the composition of wastes obtained in a conventional technology of 2,4-D production based on 2,4-dichlorophenol (2,4-DCP) of the 89% purity were presented. The influence of some homogenous catalysts on the selectivity of 2,4-dichlorophenol obtained in phenol and chlorine reaction was examined. Using the combined catalyst enables to chlorinate selectively the monochlorophenols to 2,4-DCP without an undesirable increasing of the 2,6-dichlorophenol and 2,4,6-trichlorophenol contents. The catalyst transformations during the reaction of phenol chlorination were investigated and the method of its elimination after the reaction was elaborated.

4

Utlenianie mieszaniny aceton-woda (1:5) zawierającej kwas 2,4-dichlorofenoksyoctowy z udziałem katalizatora monolitycznego platynowo-rodowego

Żarczyński A., Gorzka Z., Zaborowski M., Kaźmierczak M., Ciesielski R.

Ecological Chemistry and Engineering. S

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2009

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Vol. 16, nr 1

107-113

PL

Przedmiot badań stanowiły: modelowa mieszanina aceton-woda (1:5), zawierająca kwas 2,4-dichlorofenoksyoctowy (kwas 2,4-0) o stężeniu 2,5 g/dm3, oraz sama mieszanina aceton-woda. Natężenie przepływu powietrza wynosiło 0,215 m31h, natężenie dozowania substratu 32,5 g/h, czas kontaktu 0,36 s oraz zakres temperatury badań 400_650°C. Stosowano katalizator monolityczny platynowo-rodowy (Pt - 0,09% i Rh - 0,04% na warstwie pośredniej z y-Al2O3 naniesionej na kordieryt). Stopień konwersji TOC (OWO) ciekłych produktów reakcji względem roztworu utlenianego był większy od 99% w całym badanym zakresie temperatury. Zawartość dioksyn w spalinach z reakcji utleniania kwasu 2,4-D w temperaturze 550°C, wyznaczonej jako optymalna, wyniosła 0,0213 ng TEQ/m3. Była więc znacznie mniejsza od wartości dopuszczalnej równoważnika toksyczności równej 0,1 ng TEQ/m3.

EN

The subject of the investigation was the mixture of acetone-water (1:5) and a model solution of 2,4-D acid at the concentration of 2.5 g/dm3 in this mixture. Air flow rate was 0.215 m3/h and dose rate of the substrate was 32.5 g/dm3. The contact time was 0.36 s and the temperature ranged from 400 to 650°C. Monolithic platinum-rhodium catalyst (Pt - 0.09% and Rh - 0.04%) at an intermediate layer with y-Al2O3 deposited on cordierite, was applied in the experiments. The substrates oxidation proceeded efficiently because the TOC conversion of liquid reaction products in relation to the oxidized solution was higher than 99% in the tested temperature range. The content of PCDD/Fs in the combustion gases from the oxidation of 2,4-D acid in the optimum temperature of 550°C was 0.0213 ng TEQ/m3. This value is lower than the admissible value of the toxicity equivalent which is 0.1 ng TEQ/m3.

5

Utlenianie kwasu 2,4-dichlorofenoksyoctowego z udziałem katalizatora monolitycznego

Żarczyński A., Gorzka Z., Zaborowski M., Kaźmierczak M., Ciesielski R.

Proceedings of ECOpole

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2007

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Vol. 1, No. 1/2

283--287

PL

Przedmiot badań stanowiły: roztwór modelowy kwasu 2.4-dichlorofenoksyoctowego (kwas 2,4-D) o stężeniu 2,5 g/dm3 w mieszaninie aceton-woda (1:5) oraz sama mieszanina aceton-woda. Natężenie przepływu powietrza wynosiło 215 dm3/h natężenie dozowania substratu 32,5 g/h, czas kontaktu 0,36 s oraz zakres temperatury badań 400÷650°C. Stosowano katalizator monolityczny plalynowo-rodowy (Pt - 0,09% i Rh - 0.04% na warstwie pośredniej z ɣ-A2O3 naniesionej na kordieryt). Stopień konwersji TOC (OWO) ciekłych produktów reakcji względem roztworu utlenianego był wyższy od 99% w całym badanym zakresie temperatury. Zawartość dioksyn w spalinach z reakcji utleniania kwasu 2,4-D w temperaturze 550°C, wyznaczonej jako optymalna wyniosła 0.0213 ng TEQ/m3. Była więc znacznie mniejsza od wartości dopuszczalnej równoważnika toksyczności równej 0,1 ng TEQ/m3.

EN

The subject of the investigation was the mixture of acetone-water (1:5) and a model solution of 2,4-D acid at the concentration of 2.5 g/dm3 in this mixture. Air flow rate was 215 dm3/h and dose rate of the substrate was 32.5 g/dm3. The contact time was 0.36 s and the temperature ranged from 400 to 650°C. Monolithic platinum-rhodium catalyst (Pt - 0.09% and Rh - 0.04%) at an intermediate layer with ɣ-Al2O3 deposited at cordierite, was applied in the experiments. The substrates oxidation proceeded efficiently because the TOC conversion of liquid reaction products in relation to the oxidized solution was higher than 99% in the tested temperature range. The content of PCDD/Fs in the combustion gases from the oxidation of 2,4-D acid in the optimum temperature of 550°C was 0.0213 ng TEQ/m3. This value is lower than the admissible value of the toxicity equivalent which totals 0.1 ng TEQ/m3.