UV-fotoliza 17b-estradiola u vodenom mediju

Autor: Meheš, Mario
Přispěvatelé: Lončarić Božić, Ana
Jazyk: chorvatština
Rok vydání: 2015
Předmět:
Popis: Farmaceutici po svojoj prirodi više ili manje utječu na prirodno funkcioniranje ljudskog i životinjskog organizma, a njihova sve učestalija pojava u otpadnim vodama predstavlja potencijalnu prijetnju ljudskom i životinjskom zdravlju. Ženski spolni hormon 17β-estradiol spada u grupu farmaceutika koji imaju najjače fiziološko djelovanje, a zbog svoje široke primjene i prirodnog izlučivanja učestalo se nalazi u vodenim sustavima. Stoga se nameće potreba za istraživanjem i primjenom učinkovitih procesa obrade s ciljem njegova uklanjanja iz otpadnih tokova te sprječavanja ulaska u prirodne vodene prijemnike. U ovom radu ispitivana je fotolitička razgradnja 17β-estradiola u vodenom mediju uz pomoć ultraljubičastog zračenja. Eksperimenti su provedeni u šaržnom fotoreaktoru s vodenim hlađenjem korištenjem izvora monokromatskog zračenja: UVC (254 nm) i UVA (365 nm). Razgradnja 17β-estradiola tijekom procesa fotolize praćena je HPLC analizom s UV-DAD detektorom. Određene su vrijednosti molarnog apsorpcijskog koeficijenata i dosega kvanta zračenja kao ključnih procesnih parametara koji utječu na učinkovitost procesa fotolize. Utvrđeno je da pod utjecajem UVA zračenja ne dolazi do promjene koncentracije 17β-estradiola. UVC-fotoliza pokazala se vrlo učinkovitom u razgradnji 17β-estradiola u vodi. Nakon 45 minuta provedbe procesa UVC-fotolize razgrađeno je 96,59 % 17β-estradiola. Utvrđeno je da fotolitička razgradnja 17β-estradiola u vodi prati kinetiku pseudo prvoga reda pri čemu konstanta brzine reakcije iznosi 0,0715 min-1. Molarni apsorpcijski koeficijent iznosi 872,73 L mol-1 cm-1, a doseg kvanta zračenja 0,1068 mol Ein-1. Pharmaceuticals are natural or synthetic compounds, which have an impact on the health of humans and animals. The pharmaceuticals in wastewaters originate from human and animal excretions. Pharmaceuticals in the environment are a danger to health and ecosystem balance. The female sex hormone 17β-estradiol can be commonly found in water systems due to widespread consumption of estradiol containing pharmaceuticals and is present naturally in human and livestock excretions. 17β-estradiol increases cancer occurrence and has a negative impact on reproductive health. Therefore, research and application of efficient treatment processes are important in order to develop methods of removal and prevention of water body contamination. In this work, photodegradation of 17β-estradiol in aqueous medium was carried out under ultraviolet irradiation. The experiments were performed in a batch photoreactor, cooled by a water jacket, by means of two monochromatic light sources: UVC (254 nm) and UVA (365 nm). The rate of 17β-estradiol photodegradation was monitored by HPLC. The values of the molar absorption coefficient and the quantum yield as crucial process parameters, which affect the efficiency of the photodegradation, were determined. Under UVA degradation 17β-estradiol does not undergo photodegradation. UVC photolysis has shown to be a very efficient process for 17β-estradiol photodegradation in aqueous medium. After 45 minutes of conducting UVC photolysis 97% of 17β-estradiol has been degraded. The molar absorption coefficient of 17β-estradiol at 254 nm is equal to 872.7 L cm-1 mol-1 while the quantum yield is equal to 0.1068 mol Ein-1. The photocatalytic degradation of 17β-estradiol in aqueous media follows pseudo-first order kinetics with the reaction constant being 0.0715 min-1.
Databáze: OpenAIRE
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