Reoveesette aunkompostimine talvistes oludes
Laen...
Kuupäev
2019
Kättesaadav alates
13.09.2019
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Eesti Maaülikool
Abstrakt
Eesti reoveepuhastites on üheks peamiseks probleemiks reoveesette kompostimine just
talvistes oludes, kuna madal temperatuur pidurdab protsesse kompostimisel või ei lase
sellel üldse toimuda. Seetõttu on levinud praktika, et talvistes tingimustes sete lihtsalt
kogutakse platsidele ning kompostimisega jätkatakse alles kevadel kui sete ja aunad on
üles sulanud. See toob aga kaasa asjaolu, et kompostimiseks sobilik aeg on lühem ning
nõuab sellevõrra ka suuremaid platse, kompost haiseb, ei stabiliseeru ning kõik see seab
kahtluse all settekomposti tootena sertifitseerimise.
Käesoleva töö eesmärgiks oli uurida, kas ja millistes tingimustes on võimalik talvistes
oludes reoveesetet aunkompostida. Ühtlasi püüti välja selgitada, kas välitingimustes
kompostitud sete stabiliseerubmääruse nr 78 nõuetele kohaselt ning kas valimisse võetud
neljas reoveepuhastis valitsevad olud on kooskõlas määruse nr 24 nõuetega.
Käesoleva töö jaoks koguti andmed suvise ja talvise katse käigus. Tulemustest selgub, et
aunkompostimine on talvistes oludes võimalik, kui kasutada sobilikku tugimaterjali ning
optimeerida protsess. Suvise katse käigus semperatuur tõusis ning stabiilsus saavutati, kuid
talvise katse käigus temperatuur ei tüusnud piisavalt ja stabiilsust ei saavutatud. Mõlemaga
jõuti siiski piirväärtuse ligidale, mis tähendab, et kõigis puhastites tuleb sertifitseerimise
edendamiseks teha tööd, millest osa on tehnilist, osa organisatoorset laadi.
One of the main problems in Estonian wastewater treatment plants is composting of sewage sludge especially in winter conditions, because the low temperature slows down the process in composting or makes it impossible to take place at all. Therefore, it is common practice in winter conditions that sewage sludge is simply collected in the fields and composting continues in the spring when the sludge and windrows are melted. This leads to the fact that the time for composting is shorter and as a result, larger fields are requirred, the compost stinks and does not stabilize, this calls into question about the certification of the sediment compost as a product. The aim of this master’s thesis was to investigate whether and in which conditions it is possible to windrow compost of the sludge in winter conditions. Also author of the work tried to find out whether the composted sediment in the outdoor conditions will stabilize in accordance with the requirements of regulations No. 78 and whether the conditions of the sampled four wastewater treatment plants were in accordance with the requirements of regulation No. 24. Data for the thesis was collected during the experiment in the summer and winter. The results show that windrow composting is possible in winter conditions by using suitable support material and optimizing the process. High temperature and stability was achieved during the experiment in the summer, not in the winter. Both parameters, however, were close to limit value which shows d that in all wastewater treatment plants both technical and organizational kind of work is needed to promote certification.
One of the main problems in Estonian wastewater treatment plants is composting of sewage sludge especially in winter conditions, because the low temperature slows down the process in composting or makes it impossible to take place at all. Therefore, it is common practice in winter conditions that sewage sludge is simply collected in the fields and composting continues in the spring when the sludge and windrows are melted. This leads to the fact that the time for composting is shorter and as a result, larger fields are requirred, the compost stinks and does not stabilize, this calls into question about the certification of the sediment compost as a product. The aim of this master’s thesis was to investigate whether and in which conditions it is possible to windrow compost of the sludge in winter conditions. Also author of the work tried to find out whether the composted sediment in the outdoor conditions will stabilize in accordance with the requirements of regulations No. 78 and whether the conditions of the sampled four wastewater treatment plants were in accordance with the requirements of regulation No. 24. Data for the thesis was collected during the experiment in the summer and winter. The results show that windrow composting is possible in winter conditions by using suitable support material and optimizing the process. High temperature and stability was achieved during the experiment in the summer, not in the winter. Both parameters, however, were close to limit value which shows d that in all wastewater treatment plants both technical and organizational kind of work is needed to promote certification.
Kirjeldus
Magistritöö
Vesiehitus ja veekaitse õppekaval
Märksõnad
magistritööd, reovesi, aunkompostimine, stabiilsus, reoveepuhastid