20.500.12556/DKUM-77263 Uporaba tekoče frakcije digestata blata iz čistilnih naprav kot vira nutrientov za imobilizirane alge diplomsko delo visokošolskega strokovnega študijskega programa I. stopnje Use of liquid fraction of sewage sludge digestate as a source of nutrients for immobilized algae Kot produkt anaerobne digestije poleg bioplina nastaja tudi digestat, ki vsebuje večje količine hranil. Ker hranila v digestatu v previsokih koncentracijah onesnažujejo okolje, je za učinkovitejšo uporabo hranil (precizno kmetijstvo) potrebno digestat pred izpustom v okolje dodatno obdelati. Blato iz čistilnih naprav in digestat blata prav tako vsebujeta pomembna hranila za rastline, predvsem dušik in fosfor. Vendar pa lahko blato vsebuje tudi nevarne snovi, predvsem težke kovine in se zato ne sme uporabljati v kmetijstvu. Da se preprečijo škodljivi učinki blata na rabo tal, kakovost voda in zdravje ljudi, se ga običajno odlaga na odlagališča nevarnih odpadkov oziroma sežiga. Zaradi večje vsebnosti organskih snovi in hranil (dušik, fosfor in drugi) pa je zaželeno recikliranje le-teh. V tej raziskavi smo za odstranjevanje hranil iz tekoče frakcije digestata blata čistilnih naprav uporabili mešanico alg iz družine Scenedesmus, ki smo jih imobilizirali na nosilec iz natrijevega alginata in polivinil alkohola. Del imobiliziranih alg smo pripravili ob prisotnosti aktivnega oglja, ter preučili njegov vpliv na odstranjevanje hranil iz digestata in rast alg. Ker ima koncentrirani digestat toksičen vpliv na alge, smo pri eksperimentih uporabili 10-krat in 20-krat redčeni digestat. Največjo učinkovitost odstranjevanja hranil smo dosegli pri 20-krat redčenem digestatu. Do največjega prirasta algnih celic pa je prišlo v 10-krat redčenem digestatu. Iz digestata smo odstranili več kot 99 % fosfata in celotnega fosforja ter do 63 % amonija in 70 % celotnega dušika. Ugotovili smo, da aktivno oglje ni imelo bistvenega vpliva na učinkovitost odstranitve fosforja in dušika, prav tako ni doprineslo k povišanju števila algnih celic v nosilcih. Pozitiven vpliv aktivnega oglja smo opazili pri spreminjanju koncentracij celotnega organskega ogljika in KPK, saj so le-te bile nižje v digestatih, ki so vsebovali imobilizirane alge z dodatkom aktivnega oglja. Hkrati pa je aktivno oglje občutno prispevalo k bistrejšemu digestatu, kar nakazuje, da veže druga onesnažila prisotna v digestatu. As a product of anaerobic digestion, in addition to biogas, digestate is also formed, which contains large amounts of nutrients. As the nutrients in the digestate in high concentrations pollute the environment, it is necessary for more efficient utilization of nutrients (precision agriculture) to further process the digestate before releasing it into the environment. Sewage sludge and sludge digestate also contain important plant nutrients, especially nitrogen and phosphorus. However, sludge can also contain hazardous substances, especially heavy metals and therefore should not be used in agriculture. To prevent harmful effects of sludge on the land use, water quality and human health, sludge is usually disposed of in hazardous waste landfills or incinerated. Due to the higher content of organic substances and nutrients (nitrogen, phosphorus and others), it is desirable to recycle them. In this study, a mixture of algae from the Scenedesmus family was used to remove nutrients from the liquid fraction of the sewage sludge digestate, which was immobilized on a carrier of sodium alginate and polyvinyl alcohol. Part of the immobilized algae was prepared in the presence of activated carbon, and its effect on the removal of nutrients from the digestate and the growth of algae was studied. Because the concentrated digestate has a toxic effect on algae, 10-fold and 20-fold diluted digestates were used in the experiments. Maximum nutrient removal efficiency was achieved in 20-fold diluted digestate. The largest increase in algal cells occurred in the 10-fold diluted digestate. Almost 100 % of phosphate and total phosphorus were removed from the digestate, and up to 63 % of ammonium and up to 70 % of total nitrogen were uptook by the digestate. It was found that activated carbon in our study did not have a significant effect on the efficiency of phosphorus and nitrogen removal, nor did it contribute to an increase in the number of algae cells in the carriers. A positive effect of activated carbon was observed in changing the concentrations of total organic carbon and COD, as these were lower in digestates containing immobilized algae with the addition of activated carbon. At the same time activated carbon significantly contributed to a clearly digestate, indicating that it binds other pollutants present in the digestate. blato iz čistilnih naprav digestat anaerobne digestije vsebnost nutrientov rast alg imobilizacija alg aktivno oglje odstranjevanje nutrientov sewage sludge anaerobic digestate nutrient content algae growth algae immobilization activated carbon nutrients removal true true false [K. Smodiš] Slovenski jezik Angleški jezik Diplomsko delo/naloga 2020-08-24 16:32:55 2020-09-24 08:23:28 2022-08-09 14:34:45 2020-10-02 03:24:34 2020 0 Maribor 0 Maribor VIII, 34 str. 0000-00-00 NiDoloceno NiDoloceno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 628.336(043.2) 30433027 URN:SI:UM:DK:BK1EA1JT VS_Smodis_Kaja_2020.pdf VS_Smodis_Kaja_2020.pdf 1 4E60D81A0EEB938C134E886DFA47D4AD 47073ede89832a4cf504758d6cd75659adc276072cf4a6d5629c1a0d1b6ab122 c993953a-7c11-11eb-bb7a-00155d0001ca 20.500.12556/dkum/9ce81d5e-6173-4b4e-9b04-63a6ca44eee7 https://dk.um.si/Dokument.php?lang=slv&id=145318 Fakulteta za kemijo in kemijsko tehnologijo 0 0 0