Enzymatically activated filters for water treatment
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V posledních desetiletích se ve vodních zdrojích začaly akumulovat polutanty, které negativně ovlivňují zdraví organizmů i při nízkých koncentracích. Některé enzymy z třídy oxidoreduktáz však mají schopnost oxidovat fenolické, polyfenolické, anilinové a dokonce určité anorganické sloučeniny.Tato dizertační práce pojednává o možnosti využití enzymaticky aktivovaných filtračních systémů, počínaje porovnáním vhodných enzymů, jejich produkcí a izolací, následující imobilizací na vhodný nanovlákenný nosič, testováním efektivity při degradaci nejběžněji se vyskytujících endokrinních disruptorů v reálné vodě a nakonec nastíněním možností vývoje vhodných filtračních systémů.Ze dvou potenciálních enzymatických kandidátů (lakáza, peroxidáza) byla vybrána lakáza jako nejvhodnější pro imobilizaci na nanovlákenný nosič. Následně byla vyvinuta metoda pro imobilizaci na nanovlákna z polyamidu 6, směsi polyamid/polyetyleniminu a z kyseliny polyakrylové (PAA). Právě imobilizace na PAA prostřednictvím aktivačních činidel EDAC a S-NHS byla nejefektivnější a bylo při ní dosaženo vysoké aktivity a stability imobilizovaného enzymu. Následně byly testovány nejlepší vzorky s imobilizovanou nepřečištěnou lakázou při degradaci směsi mikropolutantů (bisfenol A, 17-ethinyletsradiol, triklosan, diklofenak) v reálné odpadní vodě. Vzorky byly velmi odolné a vysoce aktivní, a proto se ukázaly jako vhodný kandidát v technologii dočištění odpadních vod.
Over recent decades, emerging pollutants have come to represent an increasing threat to aquatic organisms due to their high persistence and tendency to accumulate in living organisms, even at low concentrations. Amongst these, several enzymes of the oxidoreductase group have shown an ability to oxidize phenolic, polyphenolic, aniline and even some inorganic compounds. This dissertation thesis comprises an outline of a water treatment method using an enzymatically activated filtration system. The thesis starts by comparing suitable enzyme candidates and methods of enzyme production and isolation and continues with methods of enzyme immobilization onto selected nanofiber supports, testing of degradation efficiency toward the most common endocrine disrupting chemicals in real water, and ends with a discussion around possible variants of a feasible model filtration system. Of two potential enzyme candidates (laccase, peroxidase), laccase was selected as the most suitable candidate for immobilization onto a nanofiber support. Subsequently, the optimal immobilization method was determined using polyamide 6, polyamide/polyethylenimine and poly(acrylic acid) nanofibers as enzyme carriers. The most effective immobilization process involved bonding laccase with poly(acrylic acid) via EDAC and S-NHS activation, which provided both high activity and stability of the attached enzyme. Finally, the best samples (with immobilized crude laccase) were tested for degradation efficiency on a mixture of micropollutants (bisphenol A, 17-ethinyletsradiol, triclosan and diclofenac) in real wastewater effluent. The samples proved both robust and highly active, and thus represent an efficient candidate for final wastewater treatment technology.
Over recent decades, emerging pollutants have come to represent an increasing threat to aquatic organisms due to their high persistence and tendency to accumulate in living organisms, even at low concentrations. Amongst these, several enzymes of the oxidoreductase group have shown an ability to oxidize phenolic, polyphenolic, aniline and even some inorganic compounds. This dissertation thesis comprises an outline of a water treatment method using an enzymatically activated filtration system. The thesis starts by comparing suitable enzyme candidates and methods of enzyme production and isolation and continues with methods of enzyme immobilization onto selected nanofiber supports, testing of degradation efficiency toward the most common endocrine disrupting chemicals in real water, and ends with a discussion around possible variants of a feasible model filtration system. Of two potential enzyme candidates (laccase, peroxidase), laccase was selected as the most suitable candidate for immobilization onto a nanofiber support. Subsequently, the optimal immobilization method was determined using polyamide 6, polyamide/polyethylenimine and poly(acrylic acid) nanofibers as enzyme carriers. The most effective immobilization process involved bonding laccase with poly(acrylic acid) via EDAC and S-NHS activation, which provided both high activity and stability of the attached enzyme. Finally, the best samples (with immobilized crude laccase) were tested for degradation efficiency on a mixture of micropollutants (bisphenol A, 17-ethinyletsradiol, triclosan and diclofenac) in real wastewater effluent. The samples proved both robust and highly active, and thus represent an efficient candidate for final wastewater treatment technology.
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imobilizace lakázy, nanovlákna, peroxidáza, čištění odpadních vod, endokrinní disrutory, laccase, peroxidase, enzyme immobilization, nanofibers, wastewater treatment, endocrine disrupting chemicals