Metaanilagunduskatte uuring Jõelähtme prügilas
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Kuupäev
2021
Kättesaadav alates
02.09.2021
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Prügilagaas tekib jäätmete lagunemisel ja see koosneb peamiselt metaanist ja süsihappegaasist. Mõlemad on kasvuhoonegaasid ning on kahjulikud nii inimestele kui ka keskkonnale. Prügilatel on kohustus tekkinud gaas koguda, kuid mingi hetk, kui gaasi hulk muutub väikseks, muutub gaasi kogumine majanduslikult ebaefektiivseks. Sellest tulenevalt on prügilasse mõistlik rajada bioaktiivne kiht, kus toimuks metaani lagundamine.
Käesoleva magistritöö eesmärk on uurida biokatte tõhusust metaani lagundamisel Jõelähtme prügilas. Katseala on rajatud Jõelähtme prügila ladestusalale, kus jäätmete ladestamine on lõppenud, ja on kaetud biokattega. Töö raames võeti proov kattematerjalist, et määrata kattematerjali ja gaasijaotuskihi materjali omadused. Biokattega alale paigaldati kaks kaheksast mõõtetorust koosnevat gaasiseirekaevu ning seitse mõõterõngast, millest kolm asub biokattega alal ja neli asub avatud prügila pinnal. Kattekihi seest mõõdeti metaani sisaldust gaasianalüsaatoriga GA5000 kohapeal, kattekihiga kaetud ja avatud prügila pinnalt koguti gaasi vakumeeritud pudelitesse, mida hiljem analüüsiti laboris. Väliuuringud toimusid perioodil august.2020 – mai.2021.
Biokattesse paigaldatud gaasiseirekaevude mõõtmistulemustest selgus, et metaani esineb kattekihi sees, kuid pinnapealsemates kihtides selle sisaldus väheneb. Biokatte pinnal on metaani sisaldus küllaltki väike võrreldes avatud prügila pinnalt mõõdetud tulemustega.
Landfill gas is produced through waste degradation and it is mainly composed of methane and carbon dioxide. Both are greenhouse gases and are harmful to people and the environment. It is mandatory to collect gas generated in landfills, but at some point, when gas production is too low to recover, it becomes economically inefficient. Therefore, it is wise to cover a landfill with a methane degradation layer. The aim of this Master’s thesis is to study the efficiency of Jõelähtme landfills’ methane degradation layer. The test site was constructed at the top of the landfill and was covered with methane degrading cover layer. During the study, samples were taken from the biocover and gas distribution layer to determine its features. Two gas wells consisting of 8-level horizontal pipes with gas collection filters were installed. Also, seven stationary rings were installed - three rings on top of the cover layer and four rings on top of waste. Methane content inside the cover layer was measured using a portable gas analyser GA5000. Gas was collected from waste and the cover layer by using vacuumed bottles, which were later analysed in the lab. Field work was conducted from August 2020 – May 2021. The results showed that methane is present throughout the entire cover layer, but at the top there is only small amounts of methane present. Methane content on the surface of the biocover is rather small compared to the amount of methane emitted from waste.
Landfill gas is produced through waste degradation and it is mainly composed of methane and carbon dioxide. Both are greenhouse gases and are harmful to people and the environment. It is mandatory to collect gas generated in landfills, but at some point, when gas production is too low to recover, it becomes economically inefficient. Therefore, it is wise to cover a landfill with a methane degradation layer. The aim of this Master’s thesis is to study the efficiency of Jõelähtme landfills’ methane degradation layer. The test site was constructed at the top of the landfill and was covered with methane degrading cover layer. During the study, samples were taken from the biocover and gas distribution layer to determine its features. Two gas wells consisting of 8-level horizontal pipes with gas collection filters were installed. Also, seven stationary rings were installed - three rings on top of the cover layer and four rings on top of waste. Methane content inside the cover layer was measured using a portable gas analyser GA5000. Gas was collected from waste and the cover layer by using vacuumed bottles, which were later analysed in the lab. Field work was conducted from August 2020 – May 2021. The results showed that methane is present throughout the entire cover layer, but at the top there is only small amounts of methane present. Methane content on the surface of the biocover is rather small compared to the amount of methane emitted from waste.
Kirjeldus
Magistritöö
Keskkonnakorralduse ja -poliitika õppekaval
Märksõnad
magistritööd, metaan, prügilagaas, metaanilagunduskate, biooksüdatsioon