magistrsko delo
Veronika Bevk (Avtor), Tjaša Griessler Bulc (Recenzent), Mojca Bavcon Kralj (Mentor)

Povzetek

Uvod: Prekomerna onesnaženost zraka je ena najpomembnejših zdravstvenih in ekoloških tem današnjega časa. Kar 99 % svetovnega prebivalstva diha zrak, ki presega vrednosti smernic kakovosti zraka. Med najpomembnejša onesnaževala zunanjega zraka spadajo benzen, toluen in ksilen. Največji vir nastanka teh spojin so emisije iz prometa. Izpostavljenost benzenu, toluenu in ksilenu škoduje zdravju, zato je razvoj učinkovitih metod preprečevanja in zmanjševanja onesnaženosti zraka s temi spojinami pomemben. Namen: Namen magistrskega dela je razvoj metode za določanje adsorpcije benzena, toluena in ksilena iz zraka na alternativno biooglje in preverjanje njegove učinkovitosti. Zanimala nas je učinkovitost adsorpcije teh spojin iz zraka na alternativno biooglje v odvisnosti od njegove granulacije in mase. Metode dela: Za testiranje adsorpcije smo uporabili filtra granulacij <0,25 mm in 0,25–0,5 mm. V prvem delu eksperimenta smo določali občutljivost metode na modelni spojini toluen in sicer tako, da smo iskali merljivo koncentracijo toluena in dovolj veliko maso filtra, ki zadrži toluen. Kot merilo učinkovitosti adsorpcije toluena smo uporabili mejno vrednost za poklicno izpostavljenost, ki znaša 192 µg/L. Adsorpcijo toluena na alternativno biooglje smo preverjali s pomočjo mikroekstrakcije na trdnem nosilcu in z uporabo plinske kromatografije z masno spektrometrijo. V drugem delu eksperimenta smo uporabnost in ponovljivost metode nadgradili z merjenjem benzena in ksilena. Izvedli smo trikratne ponovitve določanja adsorpcije za vsa tri onesnaževala. Rezultati: S pomočjo stopenjskega razredčevanja in meritev kromatografskih vrhov smo z uporabo plinske kromatografije z masno spektrometrijo določili merljivi koncentraciji toluena v parni fazi, 174 µg/L in 87 µg/L, kar predstavlja dovolj nizko območje za meritve poklicne izpostavljenosti. Rezultati kažejo, da sta filtra granulacij <0,25 mm in 0,25–0,5 mm učinkovito adsorbirala tudi benzen in ksilen. Razprava in zaključek: Pri razvoju metode smo ugotovili, da je za učinkovito adsorpcijo najbolj optimalna uporaba manjše granulacije in večje mase filtra, saj s tem dosežemo večjo aktivno površino za adsorpcijo. Pri preverjanju ponovljivosti metode smo ugotovili, da je metoda ponovljiva pri uporabi vseh treh testiranih spojin, filtrov obeh granulacij (<0,25 mm in 0,25–0,5 mm) in različnih mas. Ugotovili smo, da sta filtra pokazala potencial za odstranjevanje benzena, toluena in ksilena iz zraka. Rezultati naše raziskave lahko predstavljajo izhodišče za nadaljnje raziskave, kot sta uporaba alternativnega biooglja v praksi za odstranjevanje benzena, toluena in ksilena iz zraka in določanje adsorpcije drugih onesnaževal iz zraka.

Ključne besede

magistrska dela;sanitarno inženirstvo;benzen;toluen;ksilen;alternativno biooglje;adsorpcija;mikroekstrakcija na trdnem nosilcu;plinska kromatografija z masno sprektrometrijo;

Podatki

Jezik: Slovenski jezik
Leto izida:
Tipologija: 2.09 - Magistrsko delo
Organizacija: UL ZF - Zdravstvena fakulteta
Založnik: [V. Bevk]
UDK: 614
COBISS: 121916675 Povezava se bo odprla v novem oknu
Št. ogledov: 13
Št. prenosov: 7
Ocena: 0 (0 glasov)
Metapodatki: JSON JSON-RDF JSON-LD TURTLE N-TRIPLES XML RDFA MICRODATA DC-XML DC-RDF RDF

Ostali podatki

Sekundarni jezik: Angleški jezik
Sekundarni naslov: Development of a method for adsorption of benzene, toluene and xylene from air on alternative low-cost biochar
Sekundarni povzetek: Introduction: Air pollution is one of the most important health and environmental topics today. Most people, that means 99% of the global population, breathe air that exceeds WHO guideline limits. Benzene, toluene, and xylene belong to an important group of outdoor pollutants. Transport is one of their main sources. Exposure to benzene, toluene, and xylene can be deleterious to human health. Therefore, methods to prevent and reduce them in outdoor air are very important. Purpose: The purpose of the master's thesis was the development of a method for adsorption of benzene, toluene, and xylene from air on alternative low-cost biochar and determination of its effectiveness. We wanted to find out how two different granulations of biochar (<0.25 mm and 0.25–0.5 mm) affect different levels of adsorption. We were also interested in how the mass of biochar affects the amount of adsorbed benzene, toluene, and xylene. Methods: We used two different granulation filters (<0.25 mm and 0.25–0.5 mm) to test the adsorption. In the first part of the experiment, we determined the sensitivity of the method on the model compound, which was toluene in our case. We were looking for a measurable concentration of toluene and a proper mass of the filter, which could retain toluene. An occupational exposure limit value (192 µg/L) was used as a measure of toluene adsorption effectiveness. The adsorption of toluene on biochar was measured applying solid phase microextraction followed by gas chromatography-mass spectrometry. In the second part of the experiment, the applicability and repeatability of the method were upgraded by measuring benzene and xylene. Three replicates of the adsorption were performed for all three pollutants. Results: We determined measurable toluene concentrations: 174 μg/L and 87 μg/L, which represents a range low enough for occupational exposure measurements. The results showed that both granulation filters (<0.25 mm and 0.25–0.5 mm) also adsorbed benzene and xylene well. Discussion and conclusion: We found out that smaller filter granulation and larger filter mass provide more effective adsorption. The large active surface area allows a large amount of adsorption. We also found out that the method is repeatable for all tested compounds and both filters. Both filters showed the potential for reducing benzene, toluene, and xylene from outdoor air. The result of our research may be the starting point for further research, for example using biochar in practice for reducing benzene, toluene, and xylene from outdoor air and investigating adsorption of other pollutants from the air.
Sekundarne ključne besede: master's theses;sanitary engineering;benzene;toluene;xylene;biochar;adsorption;solid phase microextraction;gas chromatography with mass spectrometry;
Vrsta dela (COBISS): Magistrsko delo/naloga
Študijski program: 0
Konec prepovedi (OpenAIRE): 1970-01-01
Komentar na gradivo: Univ. v Ljubljani, Zdravstvena fak., Oddelek za sanitarno inženirstvo
Strani: 50 str., [2] str. pril.
ID: 16479284