Vpliv magnetnega polja na bakterije v bioloških čistilnih napravah in na pretvorbo dušika : doktorska disertacija

slovenian

doktorska dela

2013

Univerza v Mariboru, Fakulteta za strojništvo

In this doctoral dissertation we were foccusing on influence of static magnetic field (SMP) of intermediate strenght on nitrogen removal from wastewater. Current legislation and high costs of environmental taxes for water pollution call for development of advanced technologies for cleaning wastewaters. Previous published work indicated a positive role of SMF in removal of organic polutants from wastewater. In line with this our study shows that SMF of strength B = (30, 50) mT (but not B = 10 mT) had a positive influence on the removal of organic compounds in SBR reactors. Furthermore, the rate of ammonium-oxidation dramatically increased, for up to w = 85 Ž 5 % under the influence of SMF B=50mT. Based on the positive influence of SMF on wastewater treatment we continued to explore the effect of SMF on three bacteria which are commonly found in wastewater: Nitrosomonas europaea, Escherichia coli and Pseudomonas putida. The results of our research showed that SMF (B = 17 mT) has a negative influence on the growth of bacteria E. coli and P. putida, but positive on dehydrogenase activity and concentration of intracellular ATP. Inhibitory influence on the last two bacteria was the greatest at their optimal temperatures of growth. Furthermore, the results of this thesis show for the first time that SMF (B = 17 mT) has a positive influence on the oxidation of ammonium nitrogen by N.europaea bringingup to w = 60 % incerase after seven days of exposure to SMF in comparison to control samples, which were unexposed. Similarly, we oberved a positive influence on ammonium oxidation by mixed community of wastewater ammonium-oxidation bacteria present in wastewater, where conversion of ammonium to nitrate incresd for w = 40 % under the influence of SMF. Our study shows that at SMF of intermediate strenght increases removal of ammonium nitrogen from wastewater in temperature and time dependent manner and induces the growth of one of the most important nitrifiers in wastewater, namely Nitrosomonas europaea.

08.08.2023