Joanna Dorota Mankiewicz-Boczek, Bednarek A., Zaborowski A., Gagala I., Serwecinska L., Kolate E., Dziadek J. and Zalewski M.
Department of Molecular Ecohydrology. European Regional Centre for Ecohydrology of the Polish Academy of Sciences, Poland
Human activities have changed the natural flow of nitrogen, resulting in the creation of environmental problems such as increasing greenhouse gases, acidification and eutrophication. Therefore, it is necessary to develop effective methods of using the natural potential for the reduction of nitrogen compounds (NC). In order to optimize the removal of NC from agricultural areas, field model bioreactors containing different carbon sources (lignite, harl, straw or sawdust) and microbiological activators (culturable and/or unculturable bacteria) were tested. Because of the composition of agricultural sewage (pig/cattle manure) it has been necessary to develop a system that allows for the removal of both toxic forms - nitrate and ammonia. The mix of straw/carbon proved to be the best substrate for biodegradation of NC. The mix enabled a complete reduction of the nitrate load (initial concentration 448 mg/L). Additionally, the application of the activator prepared from the conglomerates of culturable denitrifying bacteria and unculturable microorganisms accelerated the reduction of ammonia (starting concentration of 260 mg/L). Summing up, the bioreactor filled with straw/coal, after the application of a microbial activator allowed for the removal of toxic NC within 6-7 weeks from leachate typical of manure storages.
Keywords: Denitrification, bioreactors, bacteria, nitrogen contaminants.