The surface water purification by ultrafiltration

Osnovni cilj magistrskega dela je bil očistiti površinsko vodo z ultrafiltracijo (UF) tako, da bi bila uporabna kot vir pitne vode. Z merjenjem posameznih parametrov in izvajanjem fizikalno - kemijskih analiz, smo ugotavljali delež odstranitve naravnih organskih snovi (NOM) in preverjali mašenje membrane, na podlagi merjenja pretokov. Proučevali smo, kaj se dogaja z NOM, merili določene analizne parametre (koncentracijo huminske kisline, kemijsko potrebo po kisiku s KMnO4, temperaturo in prevodnost), pred in po UF v permeatu (filtrirana voda). Obratovanje membrane smo izvajali pri različnih transmembranskih tlakih (TMp) (2, 3 in 4 barih). Čiščenje z UF smo izvajali na napravi Memcell, s PVC membrano tipa NADIR® PM UC030 TEST - A4, katere velikost por je bila 0,05 µm. Najprej smo določili permeabilnost membranein nato izbrali dva realna vzorca površinske vode iz reke Mure in iz reke Drave. UF smo izvajali ob različnih transmembranskih tlakih (TMp). Ker je stopnja prehajanja snovi skozi membrano sorazmerna z delovnim tlakom, smo domnevali, da bo prehajanje snovi skozi membrano hitrejše pri večjem tlaku. Ugotovili smo, da tlak nima vpliva na pretok permeata, saj se je ta med procesom UF ne glede na tlak, zmanjševal podobno, kar je bila posledica - ustvarjanje filtrnega kolača, plasti gela na membrani, koncentracijske polarizacije in mašenja por membrane. Pri večjem tlaku je bila kakovost očiščene vode z UF boljša (z večanjem tlaka sta se zmanjševali vrednost KPK in vsebnost NOM), na količino dobljenega permeata (očiščene vode) pa z večanjem tlaka nismo vplivali. Pri 4 barih se je v vzorcu reke Mure KPK znižala pod 0,1 mg/L. Pri 3 barih smo dobili največjo ponovljivost UF, zato smo pri tem transmembranskem tlaku (TMp) čistili še modelno vodo (vzorec površinske vode iz reke Mure z dodatkom 2 mg/L huminske kisline). UF je bila učinkovita, čeprav je bila koncentracija huminske kisline večja, kot v realnih vzorcih iz reke Mure in iz reke Drave.The main focus of the master\u27s thesis was to purify surface water with ultrafiltration, so it could be used as a source of drinking water. By measuring individual parameters and performing physical and chemical analysis, we determined the influence of modification on the removal of natural organic matter (NOM) and checked the membrane clogging on the basis of flow measurement. We studied what was happening with NOM, measured certain analytical parameters (concentration of humic acid, chemical oxygen demand with KMnO4, temperature and conductivity), before and after UF in permeate (filtered water). The operation of the membrane was carried out at various transmembrane pressures (TMp) (2, 3 and 4 bar). Purification with UF was carried out on the Memcell device with PVC membrane type NADIR® PM UC030 TEST - A4 with a pore size of 0.05 μm. First, we determined the permeability of membrane and then selected two realistic samples of surface water from the Mura and Drava river. UF was performed at various transmembrane pressures (TMp) and because the rate of material flow through the membrane was proportional to the working pressure, we assumed that the transition of the substance through the membrane would be faster at a higher pressure. We found that the pressure does not have an effect on the permeate flow, since during the UF process, regardless of the pressure, it decreased as a result of the formation of the filter cake, gel layer on the membrane, the concentration polarization and the membrane pore membrane. With UF at higher pressure, the quality of the purified water was better (by increasing the pressure the COD and the NOM content decreased) and the quantity of permeate obtained (purified water) was not influenced by the pressure increase. At 4 bars, the concentration of KMnO4 at 0 mg/L was reduced in the sample from the Mura river. At 3 bar, the highest reproducibility of UF was obtained, so the model water was also cleaned at this transmembrane pressure (TMp) (a sample of surface water from the Mura River with the addition of 2 mg/ L humic acid). UF was effective, although the concentration of humic acid was higher than in real samples from the Mura river and from the Drava river