Razgradnja neonikotinoidnih insekticida u pločastom fotoreaktoru

The aim of this study was to investigate the photolytic and photocatalytic degradation of neonicotinoids in an aqueous solution. Acetamiprid (ACE) and thiacloprid (TIA), two widely used insecticides, were used as model components. Experiments were performed in a flat-plate photoreactor under conditions of recirculation of the reaction mixture over an immobilised photocatalyst layer (TiO2 modified by urea) using two artificial lamps for simulation of solar irradiation (2.4 % UVB and 12 % UVA; 300–700 nm). The catalyst used was characterised by XRD, UV/Vis-DRS, BET, SEM/EDX, and CHNS analysis. All experiments were performed at room temperature and atmospheric pressure, at a recirculation flow rate of 200 cm3 min–1, and at an initial concentration of ACE and TIA of 10 mg dm–3. For most measurements, the reaction mixture was sonicated for 15 min immediately before charging the reactor. The study focused on the influence of the pH of the initial solution on the efficiency of photocatalytic and photolytic degradation. It was found that photocatalytic degradation of the two model components was most effective under acidic operating conditions, i.e., at pH 4.5, while photolysis resulted in their minimum degradation. It was also observed that pretreatment of the reaction mixture with ultrasound promoted photocatalytic degradation, while in the case of photolytic degradation, the application of ultrasound did not contribute to better degradation. Finally, photocatalytic degradation of TIA proved to be more successful than photodegradation of ACE (66.4 % vs. 25.8 %) under identical process conditions.Cilj ovog rada bio je ispitati fotolitičku i fotokatalitičku razgradnju neonikotinoida u vodenoj otopini. Acetamiprid (ACE) i tiakloprid (TIA), dva naširoko upotrebljavana insekticida, upotrijebljeni su kao modelne komponente. Istraživanja su provedena u pločastom fotoreaktoru u uvjetima recirkulacije reakcijske smjese primjenjujući imobilizirani sloj fotokatalizatora (TiO2 modificiran ureom) uz dvije komercijalne lampe za simulaciju Sunčeva zračenja (2,4 % UVB i 12 % UVA; 300 – 700 nm). Upotrijebljeni katalizator karakteriziran je analizama XRD, UV/Vis-DRS, BET, SEM/EDX i CHNS. Sva mjerenja provedena su pri sobnoj temperaturi i atmosferskom tlaku, protoku recirkulacije od 200 cm3 min–1 te uz konstantnu početnu koncentraciju ACE i TIA od 10 mg dm–3. Tijekom većine mjerenja, reakcijska smjesa izložena je djelovanju ultrazvuka u vremenu od 15 min neposredno prije punjenja reaktora. Ispitan je utjecaj početne pH vrijednosti reakcijske smjese na učinkovitost fotokatalitičke i fotolitičke razgradnje. Nađeno je da je fotokatalitička razgradnja dviju modelnih komponenti najučinkovitija u kiselim uvjetima rada, tj. pri pH 4,5, dok je fotoliza rezultirala njihovom neznatnom razgradnjom. Također, ustanovljeno je da prethodna ultrazvučna obrada reakcijske smjese pospješuje fotokatalitičku razgradnju, dok u slučaju fotolitičke razgradnje primjena ultrazvuka ne pridonosi boljoj razgradnji. Konačno, utvrđeno je da je fotokatalitička razgradnja TIA učinkovitija od fotorazgradnje ACE (66.4 % vs. 25.8 %) pri jednakim radnim uvjetima

Intensification of Photocatalytic Processes for Water and Wastewater Treatment

Velika ekonomska kriza koja se u posljednjem desetljeću osjeća u cijelom svijetu ponovno je potakla razmišljanja o potrebi “reindustrijalizacije”. Reindustrijalizacija je ekonomski, društveni, ekološki i politički proces upravljanja nacionalnim resursima s ciljem revitalizacije industrije i ostalih gospodarskih aktivnosti, a oslanja se na razvoj i primjenu novih i inovativnih tehnologija. U okviru takvih nastojanja kemijsko inženjerstvo ima odlučujuću ulogu. Prema mišljenju mnogih znanstvenika reindustrijalizacija i razvoj “industrije za budućnost” temeljit će se na tri ključna područja: očuvanju i remedijaciji okoliša, uštedi energije i poticanju razvoja obnovljivih izvora energije te zaštiti ljudskog zdravlja. To nameće i potrebu prilagodbe sustava visokog obrazovanja novim industrijskim i ekonomskim izazovima. U novije vrijeme sve se češće susrećemo s postignućima koja izlaze iz okvira “tradicionalnog” kemijskog inženjerstva, a uglavnom se zasnivaju na primjeni novog pristupa poznatog pod nazivom intenzifikacija procesa. Znanstvenici i inženjeri intenzivno rade na otkriću novih procesnih uređaja i tehnika, što predstavlja velik iskorak u odnosu na dosadašnja saznanja o kemijskim procesnim postrojenjima i omogućava razvoj integriranih, sigurnijih, energetski učinkovitijih i ekološki prihvatljivijih tehnologija. Zahvaljujući snažnom razvoju znanosti i sve većem interesu javnosti za to područje, intenzifikacija procesa postupno se počinje izdvajati kao nova disciplina unutar kemijskog inženjerstva. Zbog opsežnosti problematike u ovom radu ilustrirani su primjeri naprednih izvedbi fotokatalitičkih reaktora razvijenih primjenom metodologije intenzifikacije procesa, uključujući fotokatalitičke reaktore s rotirajućim diskom/bubnjem, mikroreaktore, membranske reaktore (sa suspendiranim i imobiliziranim fotokatalizatorom), keramičke monolite s optičkim vlaknima te uobičajene izvedbe solarnih reaktora. Istraživanja u tom području predstavljaju velik izazov s obzirom na mogućnost primjene takvih sustava za rješavanje globalnih problema u zaštiti okoliša, primarno onih vezanih uz pročišćavanje voda, otpadnih voda, uključujući i uklanjanje postojanih organskih spojeva i patogenih mikroorganizama iz vodenih resursa. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna.The global economic crisis that has been reigning in the last decade has once again encouraged thinking about the need for “reindustrialization”. Reindustrialization is an economic, social, environmental, and political process of managing national resources in order to revitalize industry and other economic activities, relying on the development and application of new and innovative technologies. Chemical engineering thereby has a crucial role. According to many scientists, the reindustrialization and development of the “industry for the future” will be based on three key areas: preservation and remediation of the environment, saving energy and encouraging the development of renewable energy sources, and protecting human health. This also highlights the need to adapt the higher education system to new industrial and economic challenges. Today, we are confronted more and more with achievements that go beyond the framework of “traditional” chemical engineering, which are mainly based on the application of a new approach known as process intensification. Scientists and engineers are intensely working on discovering new process devices and techniques, making a major step forward by enabling the development of integrated, safer, more energy efficient, and environmentally friendly technologies. Due to scientific advancement and growing public interest, process intensification is gradually starting to stand out as a new discipline within chemical engineering. Due to the scope of this issue, this paper illustrates some examples of advanced photocatalytic reactors developed using process intensification methodology, including rotating disk/drum photocatalytic reactors, microreactors, membrane reactors (with suspended and immobilized photocatalyst), optical fibre ceramic monoliths, and some representatives of the solar reactors. Research in this area represents a major challenge considering the possibility of application of such systems in solving global environmental problems, primarily those related to water and wastewater treatment, including the removal of persistent organic compounds and pathogenic microorganisms from water resources. This work is licensed under a Creative Commons Attribution 4.0 International License

Catalytic oxidation of BTEX in the monolithic reactor

Onečišćenje okoliša problem je kojem se u današnje vrijeme posvećuje sve veća pažnja. Uslijed naglog industrijskog razvoja te sve većeg inteziteta antropogenih aktivnosti u okoliš dospijeva sve veći broj onečišćujućih tvari. Hlapljivi organski spojevi koji pri normalnim uvjetima tlaka i temperature vrlo lako isparavaju predstavljaju jednu od najznačajnijih skupina spojeva koji uvjetuju onečišćenje atmosfere. Postoje brojne metode kojima se nastoji spriječiti emisija hlapljivih organskih spojeva u okoliš. Pritom se katalitička oksidacija pokazala obećavajućim postupkom razgradnje hlapljivih organskih spojeva te jednim od najučinkovitijih i ekonomski najprihvatljivijih postupaka za njihovu oksidaciju/razgradnju. Cilj ovoga rada bio je razvoj keramičkog monolitnog katalizatora za katalitičku oksidaciju aromatskih hlapljivih organskih spojeva. Razvoj katalizatora uključivao je nanošenje katalitički aktivnih komponenata na inertne monolitne nosače, pri čemu je u prvom slučaju korišten komercijalni inertni monolitni nosač (kordijerit), a u drugom slučaju je tehnologijom 3D tiska (ili aditivne proizvodnje; engl. additive manufacturing) pripremljen kristobalitni monolitni nosač. U oba slučaja kao katalitički aktivna komponenta korišten je miješani oksid mangana i bakra koji je u ranijim istraživanjima pokazao visoku učinkovitost u sličnim eksperimentalnim sustavima. Istraživanja su provedena primjenom toluena kao pojedinačne komponente i smjese organskih spojeva koja je sadržavala benzen, toluen, etilbenzen i ksilen (BTEX). Reakcije su provedene pri različitim temperaturama uz konstantan ukupan protok reakcijske smjese. Tijekom rada provedena je i usporedba aktivnosti pripremljenih katalizatora s aktivnošću komercijalnog monolitnog katalizatora koji je u svom sastavu sadržavao plemenite metale kao katalitički aktivne komponente. Nađeno je da se tehnologija aditivne proizvodnje može uspješno primijeniti za pripremu monolitnih katalizatora za katalitičku oksidaciju hlapljivih organskih spojeva. Kordijeritni monolitni i kristobalitni monolitni nosači sa slojem MnCuOx pokazali su se učinkovitim katalizatorima za oksidaciju benzena, toluena, etilbenzena i o-ksilena. Ustanovljeno je da se pripremljeni monolitni katalizatori mogu koristiti kao zamjena za skupe komercijalne katalizatore koji sadrže teško dostupne i skupe plemenite metale.Environmental pollution is a problem that is getting more and more attention nowadays. Due to the sudden industrial development and the increasing intensity of anthropogenic activities there is an increasing number of pollutants in the environment. Volatile organic compounds, which under normal pressure and temperature conditions easily evaporate, are one of the most significant groups of compounds that cause atmospheric pollution. There are numerous methods to prevent the release of volatile organic compounds into the environment. Catalytic oxidation proved to be a promising process for the degradation of volatile organic compounds and one of the most efficient and economically most acceptable processes for their oxidation / decomposition. The aim of this work was the development of a ceramic monolithic catalyst for catalytic oxidation of aromatic volatile organic compounds. The development of the catalyst involved the application of catalytically active components to inert monolithic carriers, in which a commercial inert monolithic carrier (cordierite) was used in the first case. In the other case a crystalline monolithic carrier was prepared by 3D printing technology (or additive manufacturing). In both cases mixed manganese and copper oxide were used as a catalytically active component, which in previous studies showed high efficiency in similar experimental systems. Studies were conducted using toluene as a single component and mixture of organic compounds containing benzene, toluene, ethylbenzene and xylene (BTEX). The reactions were carried out at different temperatures and a constant total flow of the reaction mixture. During the work there was also a comparison of activity of the prepared catalyst with the activity of a commercial monolithic catalyst, which in its composition contained noble metals as a catalytically active component. The experiment showed that additive manufacturing can be successfully used for the preparation of monolithic catalysts for catalytic oxidation of volatile organic compounds. During the whole process cordierite monolithic and crystalline monolithic carriers with the MnCuOx layer proved to be effective catalysts for benzene, toluene, ethylbenzene and o-xylene oxidation. It was established that prepared monolithic catalysts can be used as a substitute for expensive commercial catalysts containing heavily accessible and expensive noble metals

Catalytic oxidation of BTEX in the monolithic reactor

Onečišćenje okoliša problem je kojem se u današnje vrijeme posvećuje sve veća pažnja. Uslijed naglog industrijskog razvoja te sve većeg inteziteta antropogenih aktivnosti u okoliš dospijeva sve veći broj onečišćujućih tvari. Hlapljivi organski spojevi koji pri normalnim uvjetima tlaka i temperature vrlo lako isparavaju predstavljaju jednu od najznačajnijih skupina spojeva koji uvjetuju onečišćenje atmosfere. Postoje brojne metode kojima se nastoji spriječiti emisija hlapljivih organskih spojeva u okoliš. Pritom se katalitička oksidacija pokazala obećavajućim postupkom razgradnje hlapljivih organskih spojeva te jednim od najučinkovitijih i ekonomski najprihvatljivijih postupaka za njihovu oksidaciju/razgradnju. Cilj ovoga rada bio je razvoj keramičkog monolitnog katalizatora za katalitičku oksidaciju aromatskih hlapljivih organskih spojeva. Razvoj katalizatora uključivao je nanošenje katalitički aktivnih komponenata na inertne monolitne nosače, pri čemu je u prvom slučaju korišten komercijalni inertni monolitni nosač (kordijerit), a u drugom slučaju je tehnologijom 3D tiska (ili aditivne proizvodnje; engl. additive manufacturing) pripremljen kristobalitni monolitni nosač. U oba slučaja kao katalitički aktivna komponenta korišten je miješani oksid mangana i bakra koji je u ranijim istraživanjima pokazao visoku učinkovitost u sličnim eksperimentalnim sustavima. Istraživanja su provedena primjenom toluena kao pojedinačne komponente i smjese organskih spojeva koja je sadržavala benzen, toluen, etilbenzen i ksilen (BTEX). Reakcije su provedene pri različitim temperaturama uz konstantan ukupan protok reakcijske smjese. Tijekom rada provedena je i usporedba aktivnosti pripremljenih katalizatora s aktivnošću komercijalnog monolitnog katalizatora koji je u svom sastavu sadržavao plemenite metale kao katalitički aktivne komponente. Nađeno je da se tehnologija aditivne proizvodnje može uspješno primijeniti za pripremu monolitnih katalizatora za katalitičku oksidaciju hlapljivih organskih spojeva. Kordijeritni monolitni i kristobalitni monolitni nosači sa slojem MnCuOx pokazali su se učinkovitim katalizatorima za oksidaciju benzena, toluena, etilbenzena i o-ksilena. Ustanovljeno je da se pripremljeni monolitni katalizatori mogu koristiti kao zamjena za skupe komercijalne katalizatore koji sadrže teško dostupne i skupe plemenite metale.Environmental pollution is a problem that is getting more and more attention nowadays. Due to the sudden industrial development and the increasing intensity of anthropogenic activities there is an increasing number of pollutants in the environment. Volatile organic compounds, which under normal pressure and temperature conditions easily evaporate, are one of the most significant groups of compounds that cause atmospheric pollution. There are numerous methods to prevent the release of volatile organic compounds into the environment. Catalytic oxidation proved to be a promising process for the degradation of volatile organic compounds and one of the most efficient and economically most acceptable processes for their oxidation / decomposition. The aim of this work was the development of a ceramic monolithic catalyst for catalytic oxidation of aromatic volatile organic compounds. The development of the catalyst involved the application of catalytically active components to inert monolithic carriers, in which a commercial inert monolithic carrier (cordierite) was used in the first case. In the other case a crystalline monolithic carrier was prepared by 3D printing technology (or additive manufacturing). In both cases mixed manganese and copper oxide were used as a catalytically active component, which in previous studies showed high efficiency in similar experimental systems. Studies were conducted using toluene as a single component and mixture of organic compounds containing benzene, toluene, ethylbenzene and xylene (BTEX). The reactions were carried out at different temperatures and a constant total flow of the reaction mixture. During the work there was also a comparison of activity of the prepared catalyst with the activity of a commercial monolithic catalyst, which in its composition contained noble metals as a catalytically active component. The experiment showed that additive manufacturing can be successfully used for the preparation of monolithic catalysts for catalytic oxidation of volatile organic compounds. During the whole process cordierite monolithic and crystalline monolithic carriers with the MnCuOx layer proved to be effective catalysts for benzene, toluene, ethylbenzene and o-xylene oxidation. It was established that prepared monolithic catalysts can be used as a substitute for expensive commercial catalysts containing heavily accessible and expensive noble metals

Catalytic oxidation of BTEX in the monolithic reactor

Onečišćenje okoliša problem je kojem se u današnje vrijeme posvećuje sve veća pažnja. Uslijed naglog industrijskog razvoja te sve većeg inteziteta antropogenih aktivnosti u okoliš dospijeva sve veći broj onečišćujućih tvari. Hlapljivi organski spojevi koji pri normalnim uvjetima tlaka i temperature vrlo lako isparavaju predstavljaju jednu od najznačajnijih skupina spojeva koji uvjetuju onečišćenje atmosfere. Postoje brojne metode kojima se nastoji spriječiti emisija hlapljivih organskih spojeva u okoliš. Pritom se katalitička oksidacija pokazala obećavajućim postupkom razgradnje hlapljivih organskih spojeva te jednim od najučinkovitijih i ekonomski najprihvatljivijih postupaka za njihovu oksidaciju/razgradnju. Cilj ovoga rada bio je razvoj keramičkog monolitnog katalizatora za katalitičku oksidaciju aromatskih hlapljivih organskih spojeva. Razvoj katalizatora uključivao je nanošenje katalitički aktivnih komponenata na inertne monolitne nosače, pri čemu je u prvom slučaju korišten komercijalni inertni monolitni nosač (kordijerit), a u drugom slučaju je tehnologijom 3D tiska (ili aditivne proizvodnje; engl. additive manufacturing) pripremljen kristobalitni monolitni nosač. U oba slučaja kao katalitički aktivna komponenta korišten je miješani oksid mangana i bakra koji je u ranijim istraživanjima pokazao visoku učinkovitost u sličnim eksperimentalnim sustavima. Istraživanja su provedena primjenom toluena kao pojedinačne komponente i smjese organskih spojeva koja je sadržavala benzen, toluen, etilbenzen i ksilen (BTEX). Reakcije su provedene pri različitim temperaturama uz konstantan ukupan protok reakcijske smjese. Tijekom rada provedena je i usporedba aktivnosti pripremljenih katalizatora s aktivnošću komercijalnog monolitnog katalizatora koji je u svom sastavu sadržavao plemenite metale kao katalitički aktivne komponente. Nađeno je da se tehnologija aditivne proizvodnje može uspješno primijeniti za pripremu monolitnih katalizatora za katalitičku oksidaciju hlapljivih organskih spojeva. Kordijeritni monolitni i kristobalitni monolitni nosači sa slojem MnCuOx pokazali su se učinkovitim katalizatorima za oksidaciju benzena, toluena, etilbenzena i o-ksilena. Ustanovljeno je da se pripremljeni monolitni katalizatori mogu koristiti kao zamjena za skupe komercijalne katalizatore koji sadrže teško dostupne i skupe plemenite metale.Environmental pollution is a problem that is getting more and more attention nowadays. Due to the sudden industrial development and the increasing intensity of anthropogenic activities there is an increasing number of pollutants in the environment. Volatile organic compounds, which under normal pressure and temperature conditions easily evaporate, are one of the most significant groups of compounds that cause atmospheric pollution. There are numerous methods to prevent the release of volatile organic compounds into the environment. Catalytic oxidation proved to be a promising process for the degradation of volatile organic compounds and one of the most efficient and economically most acceptable processes for their oxidation / decomposition. The aim of this work was the development of a ceramic monolithic catalyst for catalytic oxidation of aromatic volatile organic compounds. The development of the catalyst involved the application of catalytically active components to inert monolithic carriers, in which a commercial inert monolithic carrier (cordierite) was used in the first case. In the other case a crystalline monolithic carrier was prepared by 3D printing technology (or additive manufacturing). In both cases mixed manganese and copper oxide were used as a catalytically active component, which in previous studies showed high efficiency in similar experimental systems. Studies were conducted using toluene as a single component and mixture of organic compounds containing benzene, toluene, ethylbenzene and xylene (BTEX). The reactions were carried out at different temperatures and a constant total flow of the reaction mixture. During the work there was also a comparison of activity of the prepared catalyst with the activity of a commercial monolithic catalyst, which in its composition contained noble metals as a catalytically active component. The experiment showed that additive manufacturing can be successfully used for the preparation of monolithic catalysts for catalytic oxidation of volatile organic compounds. During the whole process cordierite monolithic and crystalline monolithic carriers with the MnCuOx layer proved to be effective catalysts for benzene, toluene, ethylbenzene and o-xylene oxidation. It was established that prepared monolithic catalysts can be used as a substitute for expensive commercial catalysts containing heavily accessible and expensive noble metals

Xenobiotics in the environment

Problem onečišćenja okoliša tema je kojoj se u današnje vrijeme posvećuje sve više pažnje. Uslijed naglog industrijskog razvoja i sve većeg broja ljudi koji žive na našem planetu, u okoliš se ispušta sve više onečišćujućih tvari. Danas je sve više pozornost usmjerena na nove onečišćujuće tvari, ksenobiotike, u koje se ubrajaju farmaceutici i pesticidi. Zbog svojih fizikalnih i kemijskih svojstava farmaceutici i pesticidi nakupljaju se u okolišu u sve većim koncentracijama te ostavljaju tragove svog štetnog djelovanja na biljnom i životinjskom svijetu te na čovjeku. O farmaceuticima i pesticidima još uvijek ne postoji dovoljno podataka da bi se dobio uvid u njihovo ponašanje i utjecaj na okoliš te kako bi se spriječilo njihovo daljnje negativno djelovanje. U ovome radu prikazano je kako farmaceutici i pesticidi dospijevaju u okoliš, kakve tragove na njemu ostavljaju te koje su mogućnosti za uklanjanje nastale štete i prevenciju budućeg onečišćenja.The problem of environmental pollution is a topic that is getting more and more attention nowadays. Due to fast industrial development and an increasing number of people living on our planet, more and more pollutants are released into the environment. Today more and more attention is being paid to new pollutants or xenobiotics, to which also pharmaceuticals and pesticides belong. Because of their physical and chemical properties, pharmaceuticals and pesticides accumulate in the environment at higher and higher concentrations, which has negative effects on the plant and animal world as well as on humans. There is still not enough information about pharmaceuticals and pesticides to gain insight into their behaviour and their influence on the environment and to prevent their further negative impact. This paper shows how pharmaceuticals and pesticides get into the environment, what effects they have on it and what options we have to reverse the damage that has already been done and to prevent future contamination

Photocatalytic Degradation of Neonicotinoid Insecticides over Perlite-Supported TiO₂

The aim of this study was to investigate the photocatalytic degradation of the neonicotinoid insecticide acetamiprid in aqueous solution. Experiments were carried out in a 250 mL batch reactor with recirculation of the reaction mixture and using a UVA-LED radiation source with a heterogeneous UVC-modified perlite-based TiO2 photocatalyst. The photocatalytic degradation of acetamiprid was optimized using a Box–Behnken design (BBD) of the response surface methodology (RSM). The variables in the process optimization were catalyst type, volume of the reaction mixture, and light radiation intensity. From the experimental data obtained, the conversions of the photocatalytic reactions, the reaction rate constants, and the mean square deviations were calculated. The experimental results have shown that the conversion of the reaction is significantly affected by the type of catalyst, i.e., the method used to immobilise the photocatalytic layer on the perlite granules. The highest conversions of 48.49% were reached with catalysts obtained by impregnation methods, while the conversions were quite low (8.68%) for catalysts obtained by sol-gel methods. It was also found that the highest conversions were achieved with the highest radiation intensity and the smallest volume of reaction mixture

Ružička days : International conference 18th Ružička Days “Today Science – Tomorrow Industry” : Proceedings

Proceedings contains articles presented at Conference divided into sections: chemical analysis and synthesis, chemical and biochemical engineering, food technology and biotechnology, medical chemistry and pharmacy, environmental protection and meeting of young chemists