Dielectric barrier discharge in water solution treatment

Application of coaxial dielectric barrier discharge (DBD) reactor for treatment of different water solutions was studied. In this reactor the circulating liquid is a part of discharge electrode configuration. Thus liquid is directly exposed to UV radiation and reactive species like ozone, radicals, ions and electrons. This configuration of DBD also offers to operate the plasma with and without water falling film at one of the electrodes. Thus it can act as a plasma reactor for gas treatment and as a scrubber for soluble compounds in a gas phase, simultaneously. Here we present measurement of hydroxyl radical ("OH) in plasma treated distilled water as well as treatment of phenols, textile dyes, medicaments, herbicides and detergents

The effect of power on the degradation of propranolol by nonthermal plasma reactor

Propranolol (PRO) is a beta-blocker that is readily detected in surface water and hospital wastewater. This pharmaceutical poses a danger for aquatic animals because it is commonly prescribed for heart diseases and anxiety issues. Advanced oxidation processes are commonly tested for the decomposition of pharmaceuticals because they produce various reactive species at room conditions. A liquid-falling film dielectric barrier discharge (DBD) reactor was used for the treatment of a PRO solution, with no catalysts added. A coaxial construction, accompanied by a peristaltic pump, enables the recirculation of the treated liquid. Ambient air was selected as a feed-gas for nonthermal plasma generation under three levels of power dissipated in plasma. Direct contact of liquid film with plasma in this coaxial reactor enables the efficient transfer of reactive oxygen and nitrogen species generated in plasma to the liquid phase. The degradation rate of PRO, pH value, and conductivity were monitored after every cycle of treatment of PRO solution (100 mg/dm3), and in the presence of scavengers (t-butanol and p-benzoquinone). The PRO concentration was monitored by HPLC-DAD, at 213 nm. As expected, the highest applied power (60 W) contributed to the highest degradation rate (100%). At the same time, in these extreme conditions, pH values dropped from 6 to 2.5 and conductivity increased from 20 µS/cm to almost 1450 µS/cm in the tenth cycle of plasma treatment. Moreover, a high power yielded an excessive decontamination level, but also in the grand production of nitric acid. On the other hand, lower values of power lead to less successful endpoints, over 85% and less than 60% of degraded PRO when 35 W and 15 W were applied, respectively. Accordingly, under these conditions, the total production of ions was less intensive. The maximum conductivity value was less than 500 µS/cm for PRO treated with plasma generated by 35 W of power, and under 130 µS/cm for 15 W. To elude the exact role of reactive species, a pair of scavengers were added to a PRO solution. Both t-butanol and p-benzoquinone cut down the degradation efficiency to roughly 50%, which is 35% less than without scavengers. This result indicates an important role of hydroxyl radicals and superoxide anion radicals in air¬-generated nonthermal plasma. Advanced oxidation using this type of nonthermal plasma reactor enables the production of active species in situ while working in ambient conditions. The effectiveness of plasma treatment was confirmed with the degradation of propranolol, as a model compound for common waterborne pharmaceuticals.This conference paper was presented at the 21st European Meeting on Environmental Chemistry, held in Novi Sad, Serbia (30th of November - 3rd of December, 2021). https://emec21.rs

Optimizovana sinteza značajnog farmaceutskog intermedijera metil 4-[(1-oksopropil)fenilamino]piperidin-4-karboksilata

An efficient synthesis of methyl 4-[(1-oxopropyl)phenylamino]piperidine-4-carboxylate (7) has been developed starting from 1-benzylpiperidin-4-one (1). The compound is a key intermediate in the synthesis of new generation, highly active narcotic analgesics, such as remifintanil, as well as the novel classes of fentanyl analogues. An optimized Strecker-type condensation of piperidone 1 with aniline and HCN yielded the anilino-nitrile 2(≈90%) which, upon selective hydrolysis with conc. H2SO4, gave the anilino-amide 3.After vigorous basic hydrolysis of 3, followed by acidification and successive treatment with SOCl2 and MeOH, the anilino-ester 5 was obtained (40–45%, in 3 steps). N-Acylation of 5 with propionyl chloride yielded the anilido-ester 6(70–80%) In the final step, the catalytic N-debenzylation of 6 was examined under various conditions and optimized to yield 7 in near quantitative yields.U ovom radu razvijena je efikasna sinteza metil 4-[(1-oksopropil)fenilamino]piperidin-4-karboksilata (7), prolazeći od 1-benzil piperidin-4-on-1 (1). Jedinjenje 7 je ključni intermedijer u sintezi nove generacije visoko aktivnih narkotičkih analgetika, kao što je remifentanil a takođe i novih klasa analoga fentanyla. U optimizovanoj Strecker-ovoj kondenzaciji priperidona 1 sa anilinom i HCN, dobijen je anilino-nitril 2 (≈90%) prinos čijom je selektivnom hidrolizom pomoću konc. H2SO4 postao anilino-amid 3. Intenzivnom baznom hidrolizom ovog intermedijera, zakišeljavanjem a zatim sukcesivno reakcijom sa SOCl2 i MeOH sintetisan je anilino-estar 5 (≈40–45% prinos u 3 faze). N-acelovanjem anilino-estra 5 sa propionil hloridom postao je anilido-estar 6 (≈70–80% prinos). U poslednjom fazi sinteze izvršena je optimizacija katalitičkog N-debenzilovanja anilido-estra 6 do finalnog proizvoda 7, u približno kvantitativnom prinosu

Decolorization of reactive black 5 using dielectric barrier discharge in the presence of inorganic salts

Inorganic salts improve the coloration of textiles, which increase pollution load on dyehouse effluent in general. Decolorization of reactive textile dye C.I. Reactive Black 5 was studied using Advanced Oxidation Processes (AOPs) in a non-thermal plasma reactor, based on coaxial water falling film Dielectric Barrier Discharge (DBD). Initial dye concentration in the solution was 40.0 mg L-1. The effects of addition of inorganic salt different high concentrations (NaCl, Na2SO4 and Na2CO3) on the degree of decolorization were studied. Recirculation of dye solution through the DBD reactor with applied energy density 45-315 kJ L-1 was used. The influence of residence time was investigated after 5 minutes and 24 hours of plasma treatment. Decolorization of the dyes was monitored by spectrophotometric measurement. Changes of pH values and the conductivity of dye solution after each recirculation were tested. The most effective decolorization of over 90% was obtained with the addition of NaCl (50 g L-1), applied energy density of 135 kJ L-1 and after residence time of 24 hours of plasma treatment. Decolorization of solutions containing inorganic salts Na2SO4 and Na2CO3 were lower than for the solution without salt

Degradation herbicides with chlorine dioxide: degradation efficiency and toxicity test

The main objective of this study was to find optimal parameters for degradation of herbicides, such as nicosulfuron and thifensulfuron-methyl, with chlorine dioxide in deionized water. In order to examine the optimal parameters, degradation of herbicides was investigated under light or dark conditions with different amount of chlorine dioxide (5 and 10 ppm), different time of degradation (30 min, 1, 2, 3, 6 and 24 h) and at different pH values (3, 7 and 9). Degradation efficiency of herbicides was monitored using HPLC-DAD. Acute toxicity tests were performed for degradation products after the treatment with chlorine dioxide

Elektrohemijska degradacija Reactive Black 5 pomocu celicnih elektroda modifikovanih PbO2 i grafitnim ugljen-nitridom

Elektrode modifikovane kompozitom PbO2 sa grafitnim ugljen-nitridom (GCN) upotrebljene su za elekrohemijsku degradaciju tekstilne boje Reactive Black 5. Modifikovana čelična elektroda je korišćena kao anoda, a kao katoda čista čelična elektroda. Ispitan je uticaj strukture PbO2 na elektrokatalitičke karakteristike elektroda. Morfologija materijala je ispitana SEM-om, TEM-om i XRD-om, dok su elektrohemijske osobine ispitane uz pomoć CV i EIS merenja. Efikasnost degradacije je praćena UV-Vis spektrofotometrijom i tečnom hromatografijom. Pri optimalnim parametrima pH, koncentracije pomoćnog elektrolita, jačine struje i koncentracije ispitivane boje, najbolji rezultati su dobijeni sa elektrodom gde je cetiltrimetilamonijum-bromid (CTAB) korišćen kao templat za sintezu PbO2. Pod ovim uslovima je postignuta potpuna degradacija nakon 60 min tretmana, a proizvodi degradacije su određeni korišćenjem HPLC-MS/MS metode.Electrodes modified by PbO2 and graphite carbon nitride (GCN) composite were used for electrochemical degradation of Reactive Black 5 textile dye. A modified steel electrode was used as the anode, while a pure steel electrode was used as the cathode. The influence of PbO2 structre on electrocatalytic characteristics of electrodes was investigated. The morphology of the material was examined by SEM, TEM and XRD, while the electrochemical properties were analyzed using means of CV and EIS measurements. The degradation efficiency was monitored by UV-Vis spectrophotometry and liquid chromatography. At optimal pH parameters, supporting electrolyte concentration, current strength and test dye concentration, the best results were obtained with an electrode where cetyl trimethyl ammonium bromide (CTAB) was used as a template for PbO2 synthesis. Under these conditions, complete degradation was achieved after 60 min of treatment, and degradation products were determined using the HPLC-MS/MS method.Abstract: [https://hdl.handle.net/21.15107/rcub_cherry_6058

Elektrohemijska degradacija Reactive Black 5 pomocu celicnih elektroda modifikovanih PbO2 i grafitnim ugljen-nitridom

Elektrode modifikovane kompozitom PbO2 sa grafitnim ugljen-nitridom (GCN) upotrebljene su za elekrohemijsku degradaciju tekstilne boje Reactive Black 5. Modifikovana čelična elektroda je korišćena kao anoda, a kao katoda čista čelična elektroda. Ispitan je uticaj strukture PbO2 na elektrokatalitičke karakteristike elektroda. Morfologija materijala je ispitana SEM-om, TEM-om i XRD-om, dok su elektrohemijske osobine ispitane uz pomoć CV i EIS merenja. Efikasnost degradacije je praćena UV-Vis spektrofotometrijom i tečnom hromatografijom. Pri optimalnim parametrima pH, koncentracije pomoćnog elektrolita, jačine struje i koncentracije ispitivane boje, najbolji rezultati su dobijeni sa elektrodom gde je cetiltrimetilamonijum-bromid (CTAB) korišćen kao templat za sintezu PbO2. Pod ovim uslovima je postignuta potpuna degradacija nakon 60 min tretmana, a proizvodi degradacije su određeni korišćenjem HPLC-MS/MS metode.Electrodes modified by PbO2 and graphite carbon nitride (GCN) composite were used for electrochemical degradation of Reactive Black 5 textile dye. A modified steel electrode was used as the anode, while a pure steel electrode was used as the cathode. The influence of PbO2 structre on electrocatalytic characteristics of electrodes was investigated. The morphology of the material was examined by SEM, TEM and XRD, while the electrochemical properties were analyzed using means of CV and EIS measurements. The degradation efficiency was monitored by UV-Vis spectrophotometry and liquid chromatography. At optimal pH parameters, supporting electrolyte concentration, current strength and test dye concentration, the best results were obtained with an electrode where cetyl trimethyl ammonium bromide (CTAB) was used as a template for PbO2 synthesis. Under these conditions, complete degradation was achieved after 60 min of treatment, and degradation products were determined using the HPLC-MS/MS method.Poster: [https://hdl.handle.net/21.15107/rcub_cherry_6059

Plasma assisted degradation of pharmaceutics in water: propranolol hydrochloride as a model compound

Propranolol hydrochloride (PRO, Fig. 1), beta-blocker, is poorly degradable in wastewater treatment plants. Because of its wide use, it could pose a threat to aquatic organisms and water users. [1] The non-thermal plasma reactor (Fig. 2) is tested for degradation of propranolol hydrochloride solution (100 ppm), using different gases under the same electrical conditions (35 W of power dissipated in plasma). The concentration of PRO in samples was quantified using HPLC-DAD (213 nm), with acetonitrile and water (70/30 V/V) as eluents. The retention time of PRO was 5.100 min. The most successful propranolol hydrochloride degradation was achieved using Ar with O2 (80/20 V/V), applying 35 W of power dissipated in plasma, almost 80 % in the 1stcycle of treatment (Fig. 3). The best results with air are slightly over 80 % but in the 10th cycle of plasma reactor treatment. The presence of N2 in the air decreases the availability of reactive oxygen species, as shown in [2]. This non-thermal plasma is successful at the degradation of organic pollutants in water, such as propranolol hydrochloride, under given conditions. The level of propranolol hydrochloride degradation can be increased modifying the composition of feed gas, with best results using Ar with O2.Poster presentation held at Japan-Serbia Environmental Exchange Symposium (21. 2. 2020.), Belgrade, Serbia. Japan and Serbia have an ongoing collaboration in the environmental field. More than half of the Serbian Ministry of Environmental Protection staff were trained in Japan through various JICA programs. Exchanges are also starting in the business fields such as waste power generation. SATREPS project, “Spatial Environment Analysis and Advanced Metal Recovery System for Sustainable Resource Development” which was developed as a Global Science and Technology Cooperation Program for Global Issues was conducted for five years since April 2015. JICA technical cooperation project at the grassroots level, the “Capacity Building for Analysis and Reduction Measures of Persistent Organic Pollutants in Serbia” has been held for three years since March 2014. A new JICA project, “Environmental Improvement in Pancevo, Serbia through the Collaborations among Academia, Government, Industry and Citizens” has the same framework and will last three years from February 2020. This project is not limited to the reduction of hazardous chemicals, but aims to create a healthy environment for both humans and animals, thus the project has a working name: “Stork Project”. In this symposium, both SATREPS and JICA Partnership, the environmental exchange projects between Japan and Serbia, will jointly hold lectures and poster displays with the aim of encouraging environmental exchange between Japan and Serbia. See more here: [http://chem.bg.ac.rs/pz/news1.py?q=2506&l=0

Dielectric barrier discharge in water solution treatment

Application of coaxial dielectric barrier discharge (DBD) reactor for treatment of different water solutions was studied. In this reactor the circulating liquid is a part of discharge electrode configuration. Thus liquid is directly exposed to UV radiation and reactive species like ozone, radicals, ions and electrons. This configuration of DBD also offers to operate the plasma with and without water falling film at one of the electrodes. Thus it can act as a plasma reactor for gas treatment and as a scrubber for soluble compounds in a gas phase, simultaneously. Here we present measurement of hydroxyl radical ("OH) in plasma treated distilled water as well as treatment of phenols, textile dyes, medicaments, herbicides and detergents

Supplementary material for the article: Aonyas, M. M.; Nešić, J.; Jović, M.; Marković, M.; Dojčinović, B.; Obradović, B.; Roglić, G. M. Degradation of Triton X-100 in Water Falling Film Dielectric Barrier Discharge Reactor. Clean - Soil, Air, Water 2016, 44 (4), 422–429. https://doi.org/10.1002/clen.201500501

Supplementary material for: [https://doi.org/10.1002/clen.201500501]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/1920