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Anthropogenic pollutants
No full textAntropogene onečišćujuće tvari su tvari prisutne u okolišu nastale uslijed ljudske aktivnosti. Identificirani izvori antropogenih onečišćujućih tvari, poput industrijskih otpadnih tokova i komunalnih otpadnih voda, predstavljaju ključne izazove u očuvanju okoliša. Globalna rasprostranjenost navedenih tvari ukazuje na potrebu za međunarodnom suradnjom i propisima kako bi se suzbile negativne posljedice antropogenog onečišćenja. U okviru rada prikazani su glavni izvori antropogenih onečišćujućih tvari, njihov utjecaj na čovjeka i ostale organizme, njihova rasprostranjenost diljem svijeta te su predstavljeni postupci njihova uklanjanja. Također, istaknuti su farmaceutici kao značajna skupina antropogenih onečišćujućih tvari, s posebnim naglaskom na analgetike i anksiolitike te glavne predstavnike navedenih skupina.Anthropogenic pollutants are substances that are present in the environment as a result of human activities. Identified sources of anthropogenic pollutants, such as industrial waste streams and municipal wastewater, pose a major challenge to environmental protection.
The global distribution of these substances highlights the need for international cooperation and regulation to mitigate the negative impacts of anthropogenic pollution. The paper presents the main sources of anthropogenic pollutants, their effects on humans and other organisms, their global distribution and the methods for their removal. In addition, pharmaceuticals were highlighted as an important group of anthropogenic pollutants, with a focus on analgesics and anxiolytics and the main representatives of these groups
Determination of volatile organic compounds from air by gas and liquid chromatography
No full textLakohlapivi organski spojevi (VOC) široko su rasprostranjeni u okolišu te su prisutni u velikom broju. U zatvorenim prostorima njihova je koncentracija značajno povišena u odnosu na koncentracije u vanjskom zraku zbog čega imaju negativan utjecaj na kvalitetu zraka i ljudsko zdravlje. Njihovi su izvori brojni, od prirodnih do antropogenih, a problem u zatvorenim prostorima stvaraju zbog isparavanja iz građevinskih materijala, namještaja, sredstava za čišćenje, otpuštanja tijekom kuhanja, grijanja, korištenja proizvoda za osobnu njegu i sl.
Zbog mogućih štetnih utjecaja na zdravlje, Svjetska zdravstvena organizacija (WHO) i razne regulatorne agencije diljem svijeta (EPA, OSHA, DFG) propisuju smjernice i granične vrijednosti za dopuštene koncentracije lakohlapivih organskih spojeva u zatvorenim prostorima. Ovaj je rad bio usmjeren na razvoj i optimizaciju analitičke metode za određivanje deset lakohlapivih organskih spojeva u zraku u zatvorenim prostorima primjenom termalne desorpcije u kombinaciji s plinskom kromatografijom i plameno-ionizacijskim detektorom
(TD-GC-FID). Optimizacija metode uključivala je ispitivanje parametara headspace ekstrakcije, temperatura i vrijeme inkubacije, kao i optimizaciju parametara protoka i volumena uzoraka zraka prilikom uzorkovanja. Cilj istraživanja bio je poboljšati osjetljivost metode i osigurati pouzdanu detekciju lakohlapivih organskih spojeva.Volatile organic compounds (VOCs) are widely distributed in the environment and present in significant numbers. In indoor spaces, their concentrations are significantly higher compared to outdoor air, which negatively affects air quality and human health. Their sources are diverse, ranging from natural to anthropogenic, and in indoor environments, they pose a problem due to evaporation from building materials, furniture, cleaning products, and emissions released during cooking, heating, and the use of personal care products. Due to their potential health hazards, the World Health Organization (WHO) and various regulatory agencies worldwide (EPA, OSHA, DFG) have established guidelines and limit values for acceptable concentrations of VOCs in indoor environments. This study focused on the development and optimization of an analytical method for the determination of ten volatile organic compounds in indoor air using thermal desorption combined with gas chromatography and a flame ionization detector (TD-GC-FID). The method optimization involved investigating headspace extraction parameters, such as incubation temperature and time, as well as optimizing sampling parameters, including airflow rate and sample volume. The aim of the research was to enhance the method's sensitivity and ensure reliable detection of volatile organic compounds
The influence of the feedstock type and reaction parameters on the synthesis of fatty acid pentyl and hexyl esters
No full textReakcijom transesterifikacije u kojoj trigliceridi iz ulja/masti reagiraju s alkoholom u prisutnosti katalizatora dolazi do nastajanja alkilnih estera masnih kiselina, odnosno biodizela. Budući da se dobiva iz obnovljivih izvora, biodizel se dodaje u određenim omjerima u dizelsko gorivo, čime se smanjuje utjecaj na okoliš. Metanol se u odnosu na ostale alkohole najviše upotrebljava u proizvodnji biodizela, međutim biodizel se također može proizvoditi iz viših alkohola čija je prednost što se mogu dobiti iz obnovljivih izvora za razliku od metanola.
U ovom radu provedena je sinteza biodizela bazično kataliziranom transesterifikacijom, u prisutnosti kalijeva hidroksida, s različitim biosirovinama (suncokretovo, repičino, kokosovo, otpadno jestivo ulje i životinjska mast) te upotrebom alkohola 1-pentanola ili 1-heksanola. Istražen je utjecaj različitih reakcijskih uvjeta na iskorištenje reakcije transesterifikacije.
Uvjeti koji su se mijenjali bili su: molarni omjer alkohola i ulja/masti (5:1 i 12:1), vrijeme reakcije (2, 5, 15 i 30 minuta) te maseni udio katalizatora (1 i 3 %). Dobiveni rezultati ukazuju da molarni omjer alkohola i ulja/masti ima najveći utjecaj na iskorištenje reakcije transesterifikacije. Veliki utjecaj na iskorištenje ima i udio katalizatora, dok vrsta biosirovine i vrijeme provedbe reakcije ne utječu značajno na iskorištenje. Iskorištenja dobivena sintezom biodizela iz 1-pentanola i 1-heksanola pri istim uvjetima reakcije imaju slične vrijednosti, ali uočeno je da se povećanjem duljine alkilnog dijela lanca smanjuje iskorištenje korištenjem suncokretovog i repičinog ulja pri omjeru 5:1 s 3 mas.% KOH. Isto tako, vidljivo je da veći udio zasićenih masnih kiselina u sirovini pridonosi višem iskorištenju reakcije. Zadovoljavajuća iskorištenja dobivena su pri molarnom omjeru alkohola i ulja/masti 12:1 i 1 mas.% KOH sintezom iz suncokretovog, repičinog i otpadnog jestivog ulja te životinjske masti, dok su kod kokosovog ulja zadovoljavajuća iskorištenja postignuta korištenjem 5:1 molarnog omjera i 3 mas.% KOH.The transesterification reaction in which triglycerides from oils/fats react with alcohol in the presence of a catalyst leads to the formation of alkyl esters of fatty acids, i.e. biodiesel. Since it is obtained from renewable sources, biodiesel is added in certain proportions to diesel fuel, which reduces the impact on the environment. Compared to other alcohols, methanol is mostly used in the production of biodiesel, but it can also be produced from higher alcohols, the advantage of which is that they can be obtained from renewable sources, unlike methanol. In this work, the synthesis of biodiesel was carried out by base-catalyzed transesterification, in the presence of potassium hydroxide, with different feedstocks (sunflower, rapeseed, coconut, waste cooking oil and animal fat) and using the alcohol 1-pentanol or 1-hexanol. In addition, the influence of different reaction conditions on the yield of the transesterification reaction was investigated. The conditions that were varied were: the molar ratio of alcohol and oil/fat (5:1 and 12:1), the reaction time (2, 5, 15 i 30 minute) and the mass fraction of the catalyst (1 and 3 %). The obtained results indicate that the molar ratio of alcohol and oil/fat has the greatest influence on the utilization of the transesterification reaction. The mass fraction of the catalyst also has a great influence on the conversion, while the type of feedstock and the reaction time do not significantly affect the conversion. The yields obtained by the synthesis of biodiesel from 1-pentanol and 1-hexanol under the same reaction conditions have similar values, but it was observed that increasing the length of the alkyl chain decreases the yield using sunflower and rapeseed oil at a ratio of 5:1 with 3 wt% KOH. Also, it is evident that a higher amount of saturated fatty acids in the feedstock contributes to a higher conversion of the reaction. Satisfactory conversions were obtained at a molar ratio of alcohol and oil/fat of 12:1 and 1 wt% KOH synthesis from sunflower, rapeseed and waste cooking oil and animal fat, while with coconut oil sufficient conversions were achieved using a 5:1 molar ratio and 3 wt% KOH
Synthesis of fatty acid pentyl esters and application properties of their blends with mineral diesel
No full textPotraga za održivim izvorima energije potaknula je preispitivanje tradicionalnih goriva, potičući pojavu alternativa koje pridonose očuvanju okoliša. Za razliku od konvencionalnog dizelskog goriva koje se uglavnom dobiva iz fosilnih izvora, biodizel je privukao značajnu pažnju zbog svoje sposobnosti umanjivanja negativnih utjecaja koje na okoliš imaju emisije stakleničkih plinova i smanjenja ovisnosti o neobnovljivim resursima. Biodizel je obnovljivo gorivo dobiveno iz bioloških izvora poput biljnih ulja, životinjskih masti i otpadnih ulja za kuhanje. U ovome radu biodizel je sintetiziran iz otpadnog ulja za kuhanje dobivenog nakon prženja i alkohola 1-pentanola uz katalizator KOH procesom transesterifikacije. Sintetizirani biodizel je nakon pročišćavanja pomiješan s neaditiviranim mineralnim dizelom u različitim volumnim udjelima (2,5-20 vol. %). Uz sustav dizel-biodizel kao usporedni sustavi pripremljene su mješavine dizela i 1-pentanola te biodizela i 1-pentanola u različitim volumnim omjerima (2,5-20 vol. %). Ispitana su svojstva površinske napetosti, gustoće, viskoznosti, provedena je toplinska analiza diferencijalnom pretražnom kalorimetrijom, kao i ispitivanje niskotemperaturnih svojstava maglišta i tecišta. Izmjereni rezultati za napetost površine mješavina ne mijenjaju se s promjenom volumnih udjela komponenata FAPE i dizela. Rezultati gustoće i viskoznosti pokazuju povećanje svih vrijednosti s povećanjem volumnog udjela biodizela FAPE, no sve su vrijednosti unutar normiranih granica. Proučavanjem niskotemperaturnih svojstava rezultati maglišta i tecišta pokazuju ujednačenost i bliskost vrijednostima čistog dizela, odnosno dodatak FAPE u dizel do 20 vol.% ne utječe na pogoršanje niskotemperaturnih svojstava dizelskog goriva.The search for sustainable energy sources has spurred a reevaluation of traditional fuels, giving rise to alternatives that offer greater ecological benefits. Unlike conventional diesel fuel, primarily derived from fossil sources, biodiesel has garnered significant attention due to its ability to mitigate the negative impacts of greenhouse gas emissions and reduce dependence on non-renewable resources. Biodiesel is a renewable fuel derived from biological sources like vegetable oils, animal fats, and waste cooking oils. In this paper, biodiesel is synthesized from waste cooking oil and alcohol 1-pentanol using KOH as a catalyst via the transesterification process. The synthesized biodiesel is upon purification blended with non-additivated mineral diesel in varying volume fractions. In addition to diesel-biodiesel blends as comparative systems, mixtures of diesel and 1-pentanol, as well as biodiesel and 1-pentanol in different volume fractions, were prepared. Surface tension, viscosity, and density were the examined properties, while DSC thermal analysis was performed, along with an investigation of the low-temperature properties of cloud point and pour point. The results for surface tension are consistent regardless of the changing volume fractions of the FAPE and diesel components. The examined density and viscosity results show an increase in values with increasing volume fraction of biodiesel FAPE, but all values remain within the standardized limits. The study of low-temperature properties reveals that cloud point and pour point results are consistent and close in values to the pure diesel, i.e. the addition of FAPE to diesel up to 20 vol.% does not negatively affect the low-temperature properties of diesel fuel
Crystallization process control using direct nucleation control
No full textU ovom radu istraživana je primjena metode izravne kontrole nukleacije tijekom kristalizacije keratin monohidrata. Uspoređena su dva načina regulacije tijekom eksperimenta – standardna putem plašta i s vanjskim grijanjem. Metoda izravne kontrole nukleacije podrazumijeva vođenje procesa koje osigurava stalan broj kristala u sustavu, pri čemu se procesna temperatura regulira s obzirom brojnost kristala u sustavu. Cilj je skratiti trajanje procesa primjenom vanjskog grijala, kao i postići odgovarajuću raspodjelu veličine kristala, odnosno povećati udio većih kristala. Za praćenje broja kristala u sustavu primijenjen je mikroskop visoke rezolucije koji kontinuirano prati broj kristala u sustavu i analizira slike u stvarnom vremenu. Na temelju eksperimenata izravne kontrole nukleacije zaključeno je da se primjenom vanjskog grijanja, u usporedbi sa standardnim sustavom regulacije temperature putem plašta , ostvaruje bolja regulacija, što skraćuje provedbu procesa i rezultira formiranjem većeg broja većih kristala.This master thesis investigates the application of the direct nucleation control (DNC) during the crystallisation of creatine monohydrate. Two approaches of temperature control during the experiment were compared – standard jacket control and control with external heating. The direct nucleation control involves process control that ensures a constant number of crystals in the system. With this method, the process temperature is adjusted depending on the number of crystals present. The aim is to shorten the batch duration by external heating and to achieve a desirable crystal size distribution, in particular by increasing the proportion of larger crystals. To monitor the number of crystals in the system, a high-resolution microscope was used to enable continuous image analysis in real time and to track the counts of crystals. Based on the DNC experiments, it was found that the use of an external heating allows for faster temperature control compared to a standard batch system without an external heater, which shortens the overall process time and leads to the formation of a larger number of larger crystals
Synthesis of isobutyl and isopentyl fatty acid esters and investigation of the application properties of mixtures with mineral diesel
No full textZbog sve manje zalihe fosilnih goriva, a istovremeno sve veće potrebe za energijom radi neprestanog tehnološkog razvitka javila se potreba za alternativom iz obnovljivih izvora. Od ranih početaka izuma motora s unutarnjim izgaranjem pa sve do današnjice, kao gorivo za pogon vozila najintenzivnije se koristilo gorivo iz neobnovljivih izvora. Tokom izgaranja takvog goriva dolazi do emisije štetnih plinova što posljedično jednim dijelom uzrokuje pojavu globalnog zatopljenja. Kako bi ljudska populacija osigurala što kvalitetniju budućnost, niz znanstvenika istražuje goriva iz održivih izvora. Kao jedno od boljih rješenja spomenutog problema pokazao se biodizel. Većina komercijalnih biodizela sintetizirana je reakcijom transesterifikacije iz nižih i ravnolančanih alkohola, metanola ili etanola. U novije doba pojavio se interes za sintezom biodizela iz viših i razgranatih alkohola zbog bolje mješljivosti s mineralnim dizelom, višeg cetanskog broja, veće toplinske vrijednosti, kao i spoznaje da prisutnost strukturalnog grananja dovodi do potencijalnog poboljšanja niskotemperaturnih svojstava biogoriva. U ovom radu sintetizirani su izobutilni esteri masnih kiselina iz otpadnog jestivog ulja, uz kalijev hidroksid (KOH) kao katalizator te izopentilni esteri masnih kiselina također iz otpadnog jestivog ulja, ali uz kiseli katalizator tj. sumpornu kiselinu (H2SO4). Mješavinama biodizela, alkohola i dizela izmjerena su primjenska svojstva koristeći normirane metode te je provedena karakterizacija mješavina pomoću diferencijalne pretražne kalorimetrije (DSC) i goniometra. Svojstva koja su ispitana su kinematička viskoznost, gustoća, napetost površine, temperatura kristalizacije i entalpija kristalizacije. Viskoznost, gustoća i napetost površine smjesa povećavaju se s povećanjem udjela biodizela, a smanjuju se dodatkom alkohola. Kod mjerenja niskotemperaturnih svojstava DSC metodom dokazana je hipoteza o sniženju temperature početka i maksimuma kristalizacije upotrebljavajući za sintezu biodizela razgranate alkohole.Due to the decrease in fossil fuel reserves and the simultaneous increase in energy demand caused by continuous technological development, the demand for an alternative from renewable sources has risen. From the beginnings of the invention of the internal combustion engine to the present day, fuel from non-renewable sources has been used most intensively to power vehicles. The combustion of such fuels releases harmful gasses, which consequently and partly contribute to global warming. To ensure the best possible future for the human population, numerous scientists are researching fuels from sustainable sources. Biodiesel has proven to be one of the better solutions to this problem. Most commercial biodiesel is synthesized from lower alcohols, methanol or ethanol. Recently, there has been increased interest in synthesizing biodiesel from higher alcohols due to better miscibility with mineral diesel, higher cetane number, and higher heating value. In this work, fatty acid isobutyl esters were synthesized from waste cooking oil using potassium hydroxide (KOH) as catalyst and fatty acid isopentyl esters were also synthesized from waste cooking oil but with an acid catalyst, i.e., sulfuric acid (H2SO4). The application properties of the biodiesel, alcohol and diesel mixtures were measured using standardized methods, and their characterization was performed using differential scanning calorimetry (DSC) and a goniometer. The properties tested are kinematic viscosity, density, surface tension, crystallization temperature and enthalpy of crystallization. The viscosity, density and surface tension of the mixtures increase with increasing biodiesel content, while they decrease with the addition of alcohol. When the low-temperature properties were measured by the DSC method, the hypothesis of lowering the crystallization onset and peak temperatures by branched alcohols in the synthesis of biodiesel was confirmed
Influence of diesel-biodiesel blend composition on engine performance characteristics
No full textBiodizel je vrsta goriva koja predstavlja potencijalnu zamjenu konvencionalnom dizelskom gorivu. U ovom radu, u svrhu ispitivanja utjecaja smjese biodizela i dizelskog goriva na karakteristike rada dizelskog motora, sintetizirani su metilni (FAME), propilni (FAPRE), butilni (FABE), pentilni (FAPE) i heksilni (FAHE) esteri masnih kiselina iz otpadnog ulja reakcijom transesterifikacije, nakon čega su pročišćavani i namiješavani u dvokomponentne smjese s konvencionalnim dizelskim gorivom. Dvokomponentnim smjesama biodizela i dizelskog goriva ispitivane su karakteristike rada motora na jednocilindarskom, četverotaktnom, zrakom hlađenom dizelskom motoru s unutarnjim izgaranjem. Pripremljene su smjese FAME, FAPRE, FABE, FAPE i FAHE s dizelskim gorivom u volumnim udjelima biodizela od 5, 10, 20 i 30 %. Mjerenja na motoru provedena su pri tri različite brzine vrtnje motora od 1200, 1600 i 2000 min-1 za tri različita opterećenja motora. Mjerene su i specifične emisije ispušnih plinova s obzirom na ostvarenu snagu motora i njihovi volumni udjeli te temperatura. Dvokomponentnim smjesama biodizela FAPRE i FAPE s dizelskim gorivom u volumnom udjelu biodizela od 10, 20 i 30 % ispitivano je raspršenje za tlak ubrizgavanja od 300, 500 i 700 bara za četiri različite duljine ubrizgavanja u trajanju od 0,6, 0,8, 1 i 3 ms. Smjese su ubrizgavane u stakleni okvir za atmosfersko ubrizgavanje, a domet i kut raspršenja mlaza određivani su sustavom za mjerenje s visokobrzinskom kamerom i laserom. Kako bi se podaci o karakteristikama rada dizelskog motora i raspršenja mogli dodatno potkrijepiti, svim smjesama biodizela i dizelskog goriva te čistim komponentama određene su kinematička viskoznost i gustoća pri četiri različite temperature od 15, 25, 40 i 60 °C. Na temelju provedenog ispitivanja, zaključeno je da je domet smjesa biodizela veći, a kut raspršenja manji u odnosu na čisto dizelsko gorivo zbog veće viskoznosti i gustoće biodizela. Potvrda tome su i podaci dobiveni mjerenjem viskoznosti i gustoće smjesa biodizela i dizelskog goriva. Mjerenjem karakteristika rada motora, dobiveno je da su emisije dušikovih oksida (NOx) i ukupnih ugljikovodika (THC) uglavnom manje, a emisije ugljikovog monoksida (CO) i dioksida (CO2) veće za smjese biodizela u odnosu na čisto dizelsko gorivo.Biodiesel is a type of fuel that represents a potential replacement for conventional diesel fuel. In this work, for the purpose of examining the influence of a mixture of biodiesel and diesel on the performance characteristics of a diesel engine, methyl (FAME), propyl (FAPRE), butyl (FABE), pentyl (FAPE) and hexyl (FAHE) esters of fatty acids from waste cooking oil were synthesized via transesterification reaction, after which they were purified and mixed into two-component mixtures with conventional diesel fuel. Two-component mixtures of biodiesel and diesel were used to test the performance characteristics of a single-cylinder, four-stroke, air-cooled, internal combustion diesel engine. Mixtures of FAME, FAPRE, FABE, FAPE and FAHE with diesel were prepared in biodiesel volume fractions of 5, 10, 20 and 30 %. Measurements on the engine were performed at three different engine speeds of 1200, 1600 and 2000 min-1 for three different engine loads. Specific emissions of exhaust gases were also measured with regards to the achieved engine power and their volume ratios and temperature. Two-component mixtures of biodiesel FAPRE and FAPE with diesel in a volume fraction of biodiesel of 10, 20 and 30 % were tested for dispersion at injection pressures of 300, 500 and 700 bar with four different injection durations of 0,6, 0,8, 1 and 3 ms. The mixtures were injected into a glass frame for atmospheric injection, penetration and angle of the jet dispersion were determined by a measurement system with a high-speed camera and a laser. In order to further support the data on diesel engine operation characteristics and dispersion, kinematic viscosity and density were determined for all biodiesel and diesel mixtures and pure components at four different temperatures of 15, 25, 40 and 60 °C. Based on the conducted test, it was concluded that the range of biodiesel mixtures is greater and the fuel injection angleis lower compared to pure diesel due to the higher viscosity and density of biodiesel. This is confirmed by the data obtained by measuring the viscosity and density of biodiesel and pure diesel mixtures. By measuring the performance characteristics of the engine, it was found that the emissions of nitrogen oxides (NOx) and total hydrocarbons (THC) are mostly lower, and the emissions of carbon monoxide (CO) and dioxide (CO2) are higher for biodiesel mixtures compared to pure diesel
Emerging contaminants in water
No full textNove onečišćujuće tvari u vodama su kemijski spojevi čija je prisutnost u vodama tek otkrivena ili je tek otkriven njihov štetan utjecaj na ljudsko zdravlje i okoliš. Sadržane su u proizvodima koji se svakodnevno koriste, a radi manjka istraživanja i znanja o njima, ne postoji mnogo zakonskih regulativa. To sve doprinosi njihovoj širokoj prisutnosti. Glavni izvor novih onečišćujućih tvari u vodama su postrojenja za pročišćavanje otpadnih voda s konvencionalnim obradama koja su nedovoljno prilagođena za uklanjanje novih onečišćujućih tvari što rezultira njihovim ispuštanjem u okoliš. U ovom radu definirane su nove onečišćujuće tvari i njihovi izvori. Kao glavni izvor novih onečišćujućih tvari u vodi, istaknute su otpadne vode i navedene su neke od naprednih fizikalno-kemijskih i bioloških obrada. U preglednom dijelu pobliže su objašnjeni endokrini disruptori i antibiotici, te njihovi štetni utjecaji na zdravlje ljudi i okoliš.Emerging contaminants in water are chemical compounds whose presence in water has just been discovered or whose adverse effect on human health and environment has just been discovered. They are contained in products that are used on a daily basis, and due to lack of research and knowledge about them, there are not many legal regulations. That contributes to their ubiquitous presence. The main source of emerging contaminants in water are wastewater treatment plants with conventional treatments that are inadequate to remove emerging contaminants, resulting in their release into the environment. In this paper, emerging contaminants and their sources are defined. Wastewater is highlighted as the main source of emerging pollutants in water and some of the advanced physico-chemical and biological treatments are listed. In the review section, endocrine disruptors and antibiotics are explained in more detail, as well as their harmful effects on human health and the environment
Fotooksidativna razgradnja antivirusnih lijekova: Ribavirin i Emtricitabin
No full textOver the past few decades, advancements in pharmaceuticals have greatly enhanced human quality of life. However, the production and widespread use of these medications have led to their presence in the environment, posing risks to various organisms. Pharmaceuticals, along with their metabolites and degradation products, can be highly persistent, accumulating over time and reaching concentrations that may be toxic to ecosystems. Consequently, it is crucial to investigate their environmental stability and persistence, as well as the potential degradation products that form. The pandemic of COVID-19 has resulted in the wide application of antiviral drugs, including ribavirin and emtricitabine, hence their raised occurrence in the environment. This study describes the photo-oxidative degradation of two antiviral drugs ribavirin and emtricitabine using advanced oxidation processes (AOPs): UV/H2O2 and UV/S2O82– to reduce their impact on the environment. Advanced oxidation processes are advanced technologies for the degradation of persistent organic pollutants in water. This process generates highly reactive species that are capable of degrading complex organic molecules into less harmful compounds. Therefore, this research was aimed at studying the efficiency of UV/H2O2 and UV/S2O82– systems for the degradation of ribavirin and emtricitabine under a variety of selected conditions, including oxidant doses, pH conditions, and different times of irradiation.
The degradation kinetics was studied with a view to defining suitable operational parameters that could help achieve maximum removal efficiency. Thus, the results indicated that both
UV/H2O2 and UV/S2O82– were highly efficient in the degradation enhancement of targeted compounds, ribavirin and emtricitabine, with respect to UV irradiation alone. In the case of emtricitabine degradation, UV/S2O82– was much more efficient, while for the degradation of ribavirin, was seen a good progress performance which was obtained both by UV/H2O2 and UV/S2O82–. These results indicate that AOPs may have great potential to be applied for the treatment of pharmaceutical contaminants present in wastewater and minimize their impact on the environment.Tijekom posljednjih nekoliko desetljeća, napredak u farmaceutskim proizvodima uvelike je poboljšao kvalitetu ljudskog života. Međutim, proizvodnja i široka uporaba ovih lijekova doveli su do njihove prisutnosti u okolišu, što predstavlja rizik za razne organizme. Farmaceutski proizvodi, zajedno sa svojim metabolitima i produktima razgradnje, mogu biti vrlo postojani, akumulirajući se tijekom vremena i dostižući koncentracije koje mogu biti toksične za ekosustave. Stoga je ključno istražiti njihovu stabilnost i postojanost u okolišu, kao i moguće produkte razgradnje koji nastaju. Pandemija COVID-19 rezultirala je širokom primjenom antivirusnih lijekova, uključujući ribavirin i emtricitabin, pa stoga i njihova povećana pojava u okolišu. Ova studija opisuje fotooksidacijsku razgradnju dvaju antivirusnih lijekova ribavirina i emtricitabina korištenjem naprednih oksidacijskih procesa (AOP): UV/H2O2 i UV/S2O82– kako bi se smanjio njihov utjecaj na okoliš. Napredni oksidacijski procesi su napredne tehnologije za razgradnju postojanih organskih onečišćujućih tvari u vodi. Ovaj proces stvara visoko reaktivne vrste koje su sposobne razgraditi složene organske molekule u manje štetne spojeve. Stoga je ovo istraživanje bilo usmjereno na proučavanje učinkovitosti
UV/H2O2 i UV/S2O82– sustava za razgradnju ribavirina i emtricitabina pod različitim odabranim uvjetima, uključujući doze oksidansa, pH uvjete i različita vremena zračenja. Kinetika razgradnje proučavana je s ciljem definiranja odgovarajućih radnih parametara koji bi mogli pomoći u postizanju maksimalne učinkovitosti uklanjanja. Stoga su rezultati pokazali da su i UV/H2O2 i UV/S2O82– vrlo učinkoviti u poboljšanju razgradnje ciljanih spojeva, ribavirina i emtricitabina, s obzirom na samo UV zračenje. U slučaju razgradnje emtricitabina, UV/S2O82– bio je mnogo učinkovitiji, dok je za razgradnju ribavirina uočen dobar napredak koji je postignut i UV/H2O2 i UV/S2O82–. Ovi rezultati pokazuju da AOP mogu imati veliki potencijal za primjenu za obradu farmaceutskih kontaminanata prisutnih u otpadnim vodama i minimiziranje njihovog utjecaja na okoliš
Synthesis and characterisation of a cellulose derivative and dibutyl maleate graft copolymer
No full textCeluloza je zastupljen polisaharid u prirodnom svijetu. Nalazi se u staničnim stijenkama biljaka, a može se dobiti i iz drugih izvora poput bakterija. Iz tog je razloga ona, kao sirovina, vrlo pristupačna. Zbog svoje biokompatibilnosti vrlo je zastupljena u farmaceutskoj industriji za svrhe poput dostave lijekova unutar organizma. Zbog jakih intermolekularnih interakcija, celuloza nije topiva u većini otapala, što u farmaceutskoj industriji nije poželjno. Iz tog razloga se često koriste njeni derivati gdje su hidroksilne skupine zamijenjene drugim funkcionalnim skupinama. U ovom se radu provodila cijepljena kopolimerizacija natrij karboksimetil celuloze dibutil maleatom uz inicijator cerij (IV) amonijev nitrat te cijepljena kopolimerizacija (hidroksipropil)metil celuloze s kopolimerom maleinskog anhidrida i dibutil maleata uz inicijator azobisizobutironitril. Svrha ovog rada bila je sinteza cijepljenih kopolimera radi njihove potencijalne primjene kao stabilizatorima aktivnih farmaceutskih sastojaka. Dobiveni produkti su karakterizirani diferencijalnom pretražnom kalorimetrijom, termogravimetrijskom analizom i infracrvenom spektroskopijom s Fourierovim transformacijama.
Uspješno je sintetiziran kopolimer natrij karboksimetil celuloza-graft-poli(dibutil maleat) (NaCMC-g-DiBuMal), ali uz nisko iskorištenje reakcije od 3%.Cellulose is a abundant polysaccharide nature. It is found in the cell walls of plants and can also be obtained from other sources like bacteria, making it an easily accessible raw material. Due to its biocompatibility, cellulose is widely used in the pharmaceutical industry for applications such as drug delivery. However, because of its strong intermolecular interactions, cellulose is not soluble in most solvents, which is undesirable in pharmaceutical applications. To address this issue, derivatives of cellulose are often used, where the hydroxyl groups are replaced with other functional groups. In this study, graft copolymerization of sodium carboxymethyl cellulose (NaCMC) with dibutyl maleate was conducted using cerium (IV) ammonium nitrate as the initiator. Additionally, graft copolymerization of (hydroxypropyl)methyl cellulose with a copolymer of maleic anhydride and dibutyl maleate was carried out using azobisisobutyronitrile as the initiator. The purpose of this study was to synthesize graft copolymers for their potential application as stabilizers of active pharmaceutical ingredients. The products obtained were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and
Fourier-transform infrared spectroscopy (FTIR). The copolymer sodium carboxymethyl cellulose-graft-poly(dibutyl maleate) (NaCMC-g-DiBuMal) was successfully synthesized, butSwith a reaction yield of 3% while the syntesis using HPMC yielded no result