RESUMEN
Attached activated sludge from the Krasnaya Polyana (Sochi) wastewater treatment plant was studied after the reconstruction by increased aeration and water recycle, as well as by the installation of a bristle carrier for activated sludge immobilization. The activated sludge biofilms developing under conditions of intense aeration were shown to contain both aerobic and anaerobic microorganisms. Activity of a strictly anaerobic methanogenic community was revealed, which degraded organic compounds to methane, further oxidized by aerobic methanotrophs. Volatile fatty acids, the intermediates of anaerobic degradation of complex organic compounds, were used by both aerobic and anaerobic microorganisms. Anaerobic oxidation of ammonium with nitrite (anammox) and the presence of obligate anammox bacteria were revealed in attached activated sludge biofilms. Simultaneous aerobic and anaerobic degradation of organic contaminants by attached activated sludge provides for high rates of water treatment, stability of the activated sludge under variable environmental conditions, and decreased excess sludge formation.
Asunto(s)
Biopelículas , Aguas del Alcantarillado/microbiología , Aguas Residuales/microbiología , Microbiología del Agua , AnaerobiosisRESUMEN
The methanogenic activity of manure destructors was investigated at different stages of cattle manure utilization at 35 degrees in a three-section horizontal methane tank manufactured by "Enbom" company (Finland). The association of microorganisms was found to have the highest activity at the last stage of the process, while the least activity was observed in case of fresh manure. A considerable increase of the methanogenic activity in the methane tank was proved by the radioisotopic method and by calculation of the population size of microorganisms from different groups by the series dilution method. Acetic and propionic acids were absent in samples from the third section of the methane tank, while the maximum concentration of the acids was found in the manure storage and in the first section of the methane tank. A significant part of active methanogenic microorganisms was removed with the effluent. Therefore, partial recirculation of the biomass should be used to increase the efficiency of the methane tank.