Biolagunevatest jäätmetest toodetud sertifitseeritud kompostis esinevad võõrised
Laen...
Kuupäev
2022
Kättesaadav alates
02.09.2022
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Biolagunevate jäätmete taaskasutuseks on kompostimine parim käitlusviis. Kompostimine
võimaldab vähendada jäätmejaamadesse ladestatavatest jäätmetest eralduvaid kasvuhoonegaase
ning valmiskompost on väärtuslik mullaparandaja, mis pakub alternatiivi mineraalväetistele.
Eestis on viis jäätmejaama, millele on omistatud sertifikaat biojäätmetest komposti
valmistamiseks. Sertifitseeritud kompost peab vastama kõigile seadusandluses sätestatud
nõuetele.
Käesoleva magistritöö eesmärgiks on välja selgitada kas ja millises mahus leidub sertifitseeritud
kompostides mullale mitteomast biolagunematut materjali ja millistes fraktsioonides ning
millisest materjalist nimetatud objektid on. Selleks kasutati kuue erineva partii valmiskomposte,
mis esmalt õhk-kuivatati ning sõeluti seitsme erineva suurusega fraktsioonidesse suurusega <1
mm kuni >10 mm. Iga proovi uuriti ükshaaval. Võõrised eraldati proovidest kasutades visuaalset
vaatlust ja magnetit. Võõrised eraldati materjali alusel ning kõigi proovide puhul kaaluti eraldi
metallist, klaasist ja plastist võõrised. Plasti puhul määrati lisaks massile ka proovidest eraldatud
osakeste pindala.
Magistritöö tulemusel leiti, et kuuest kompostist nelja puhul oli võõriste hulk piirnormist suurem.
Visuaalse vaatluse käigus oli võimalik plasti ja klaasi orgaanilisest materjalist eristada ka kõige
väiksemas fraktsioonis, milles osakeste suurus oli väiksem kui 1 mm. Peamiselt leidus võõriseid
väiksemates fraktsioonides; 2-4 mm ja 1-2 mm. Massi poolest moodustas võõristest enamuse
metall. Ühiku kaupa loendades oli kõige rohkem plasti osakesi. Keskmiselt leiti 250 grammi
komposti kohta 19-118 ühikut võõriseid massiga 0,79-3,36. Enim võõriseid sisaldanud toote
puhul oli plastist osakeste pindala 250-grammises proovi kohta keskmiselt 12,48 cm2
.
Suurim
hulk võõriseid leiti kompostist, mille tootmiseks oli lisaks aia- ja haljastujäätmetele kasutatud köögi- ja sööklajäätmeid. Antud toote puhul oli kogu lähtematerjal enne kompostimist purustatud
ilma biolagunematuid materjale eemaldamata.
Kuigi jäätmekäitlejad rakendavad komposti tootmisel nii eel- kui järelkäitluse käigus erinevaid
võtteid biolagunematu materjali eemaldamiseks, leiti käesoleva magistritöö raames uuritud nelja
toote puhul kuuest visuaalse vaatluse käigus lubatust rohkem võõriseid. Töö tulemused viitavad,
et valmiskompostis võõriste vältimiseks on väga oluline, et biolagunevad jäätmed oleks
võõristest vabad juba tekkekohas kogudes.
Eestis ei ole varem sellist uuringut läbi viidud ning antud töö tulemused võivad olla oluliseks
lähtekohaks järgnevateks uuringuteks.
Composting is the best way to recycle biodegradable waste. It helps reduce the amount of greenhouse gas emissions from landfills. Mature compost is also a valuable soil improver offering a good alternative to mineral fertilisers. There are five recycling facilities in Estonia that are certified to produce high quality compost from biowaste. Compost certified as a product needs to meet all standards set by the legislation in force. The maximum amount of foreign matter allowed in compost is 0,5% of dry weight. The purpose of this study is to confirm whether there are man-made contaminants in certified composts, which fraction of compost contains the most foreign particles and of which material. Six different patches of composts were used. These were all air-dried and sieved to seven different fractions ranging from <1 mm to >10 mm. Each sample was visually checked for foreign particles and metals were removed by using a magnet. The retrieved foreign particles were sorted by materials and weighed in following groups: metals, glass, and plastics. In addition to weight the surface area of the plastics was calculated. The results of this thesis found concentrations of foreign particles above the 0,5% norm in four of the six composts studied. It was possible to extract particles of glass and plastics even from the smallest of fractions, which was <1 mm. Most foreign particles were found in the smaller fractions: 2-4 mm and 1-2 mm. Metals had the highest weight but counting the particles, plastics had the highest count. On average 19-118 units of foreign particles weighing 0,97-3,3 6g were found in 250 grams of compost. The product with the highest count of foreign particles had an average of 12,48 cm2 of plastics in a 250-gram sample. The compost containing the most foreign particles had kitchen waste and garden waste as feedstock. The whole pile of waste had been crushed before composting without removing any non-biodegradable materials. Although recycling facilities apply measures to remove non-biodegradable materials during both pre- and post-treatment of composting, four of the samples used in this research contained foreign particles in amounts higher than allowed by national regulations. Results of this thesis imply that it is crucial to separate non-biodegradable materials from biowastes before they reach recycling facilities. No similar research has been conducted in Estonia and the results of this paper can be used as a starting point for next studies.
Composting is the best way to recycle biodegradable waste. It helps reduce the amount of greenhouse gas emissions from landfills. Mature compost is also a valuable soil improver offering a good alternative to mineral fertilisers. There are five recycling facilities in Estonia that are certified to produce high quality compost from biowaste. Compost certified as a product needs to meet all standards set by the legislation in force. The maximum amount of foreign matter allowed in compost is 0,5% of dry weight. The purpose of this study is to confirm whether there are man-made contaminants in certified composts, which fraction of compost contains the most foreign particles and of which material. Six different patches of composts were used. These were all air-dried and sieved to seven different fractions ranging from <1 mm to >10 mm. Each sample was visually checked for foreign particles and metals were removed by using a magnet. The retrieved foreign particles were sorted by materials and weighed in following groups: metals, glass, and plastics. In addition to weight the surface area of the plastics was calculated. The results of this thesis found concentrations of foreign particles above the 0,5% norm in four of the six composts studied. It was possible to extract particles of glass and plastics even from the smallest of fractions, which was <1 mm. Most foreign particles were found in the smaller fractions: 2-4 mm and 1-2 mm. Metals had the highest weight but counting the particles, plastics had the highest count. On average 19-118 units of foreign particles weighing 0,97-3,3 6g were found in 250 grams of compost. The product with the highest count of foreign particles had an average of 12,48 cm2 of plastics in a 250-gram sample. The compost containing the most foreign particles had kitchen waste and garden waste as feedstock. The whole pile of waste had been crushed before composting without removing any non-biodegradable materials. Although recycling facilities apply measures to remove non-biodegradable materials during both pre- and post-treatment of composting, four of the samples used in this research contained foreign particles in amounts higher than allowed by national regulations. Results of this thesis imply that it is crucial to separate non-biodegradable materials from biowastes before they reach recycling facilities. No similar research has been conducted in Estonia and the results of this paper can be used as a starting point for next studies.
Kirjeldus
Magistritöö
Keskkonnakorralduse ja -poliitika õppekaval
Märksõnad
magistritööd, kompost, mikroplast, jäätmekäitlus, väetis