Uporaba ligninolitičnih encimov za razgradnjo organskega onesnaženja v odpadnih vodah

Zibelnik, Matic (author), Žgajnar Gotvajn, Andreja (mentor)

Onesnaženost okolja se v zadnjih nekaj desetletjih povečuje zaradi prekomernega in pogosto namernega sproščanja nevarnih in škodljivih snovi. Številne raziskave so zato namenjene razvoju novih, okolju prijaznih procesov, ki bi zmanjšali ali celo odpravili onesnaženje. Za eno od učinkovitih in zanesljivih metod sanacije onesnaženih območij se je izkazala bioremediacija. Med te sodi tudi mikoremediacija, ki s pomočjo gliv in njihovih encimov učinkovito razgradi organska onesnaženja. Namen magistrske naloge je bil preiskati možnosti uporabe ligninolitičnih encimov lakaz glive Dichomitus squalens za odstranjevanje onesnaženja. Najprej za razbarvanje azo barvila Chicago sky blue, nato pa za razgradnjo organskih onesnaževal iz farmacevtske odpadne vode in odpadne vode kovinske industrije. Encimi so se pri razbarvanju azo barvila izkazali za učinkovite, saj so v 140 minutah uspeli razbarvati 90 % barvila. Pri farmacevtski odpadni vodi encimi niso uspeli razgraditi organskega onesnaženja, saj sta kemijska potreba po kisiku in koncentracija raztopljenega organskega ogljika ostala ves čas nespremenjena. Vpliv odpadne vode na aktivnost lakaz je velik, saj aktivnost že v prvih dveh dneh pade za 50 %. Tako smo zaključili, da lakaze glive Dichomitus squalens ne predstavljajo možnosti za razgradnjo organskega onesnaženja, prisotnega v farmacevtski odpadni vodi. Pri odpadni vodi iz kovinske industrije so lakaze le delno razgradile organsko onesnaženje. V osmih dneh se je kemijska potreba po kisiku zmanjšala za 26 %, koncentracija raztopljenega organskega ogljika pa za 31 %. V zadnjem delu je bila opravljena analiza razbarvanja farmacevtske odpadne vode in odpadne vode iz kovinske industrije. Pri farmacevtski odpadni vodi analiza ni pokazala nobenih sprememb. Pri odpadni vodi iz kovinske industrije pa je sprememba opazna pri vseh treh valovnih dolžinah. V osemdnevnem poskusu voda ne doseže mejnih vrednosti za izpust, vendar bi to morda lahko dosegli s podaljšanjem poskusa. Tako smo zaključili, da imajo lakaze glive Dichomitus squalens potencial za čiščenje odpadnih vod iz kovinske industrije.

• Language: Slovenian
• Keywords: bioremediacija, glive bele trohnobe, ligninolitični encimi
• Work type: Master's thesis/paper
• Typology: 2.09 - Master's Thesis
• Organization: FKKT - Faculty of Chemistry and Chemical Technology
• Year: 2021
• PID: 20.500.12556/RUL-124710
• COBISS.SI-ID: 51654659
• Publication date in RUL: 11.02.2021

Secondary language

• Language: English
• Title: The use of ligninolytic enzymes for degradation of organic pollution in wastewaters

Abstract

Environmental pollution has increased in the past few decades due to the indiscriminate and frequently deliberate release of hazardous and harmful substances. Therefore numerous studies have been focused on the development of new, environmentally friendly processes that could reduce and even eliminate pollution. The remediation of contaminated sites using bioremediation seems to be one of the most effective and reliable methods. Among them, fungi and their enzymes have a great potential to effectively convert and degrade organic pollution. The aim of the master's thesis was to evaluate the Dichomitus squalens ligninolytic enzyme laccase's potential for the degradation of pollutants. First the decolourisation of azo dye Chicago sky blue was investigated and then the decomposition of organic pollutants from pharmaceutical wastewater and metal industry wastewater was assessed. Enzymes showed to be effective towards azo dye, as they managed to decolourise 90% in 140 minutes. In pharmaceutical wastewater, enzymes were unable to degrade organic pollution, since Chemical oxygen demand and Dissolved organic carbon remained constant throughout the experiment. The impact on laccase activity is large, as the activity drops by 50% in first 2 days. It can be concluded that laccase of fungi D. squalens does not have the potential to degrade the organic pollution present in pharmaceutical wastewater. In metal industry wastewater, enzymes only partially degraded organic pollution. Within 8 days of experiment COD dropped by 26% and DOC by 31%. During the last stage, the decolourisation of pharmaceutical wastewater and metal industry wastewater was evaluated. In pharmaceutical wastewater, the analysis showed no changes. In metal industry wastewater the change was noticeable at all 3 wavelengths. In 8-day experiment the water still does not reach the discharge limits; however, this could be achieved by prolonging the experiment. It can be concluded that laccase of fungi Dichomitus squalens have the potential to treat metal industry wastewater.

• Keywords: bioremediation, ligninolytic enzyme, white rot fungi