Deammonification process start-up after enrichment of anammox microorganisms from reject water in a moving-bed biofilm reactor

Abstract

Deammonification via intermittent aeration in biofilm process for the treatment of sewage sludge digester supernatant (reject water) was started up using two opposite strategies. Two moving-bed biofilm reactors were operated for 2.5 years at 26 (+/- 0.5 degree C with spiked influent(and hence free ammonia (FA)) addition. In the first start-up strategy, an enrichment of anammox biomass was first established, followed by the development of nitrifying biomass in the system (R1). In contrast, the second strategy aimed at the enrichment of anammox organisms into a nitrifying biofilm (R2). The first strategy was most successful, reaching higher maximum total nitrogen (TN) removal rates over a shorter start-up period. For both reactors, increasing FA spiking frequency and increasing effluent concentrations of the anammox intermediate hydrazine correlated to decreasing aerobic nitrate production (nitritation). The bacterial consortium of aerobic and anaerobic ammonium oxidizing bacteria in the bioreactor was determined via denaturing gel gradient electrophoresis, polymerase chain reaction and pyrosequencing. In addition to a shorter start-up with a better TN removal rate, nitrite oxidizing bacteria (Nitrospira) were outcompeted by spiked ammonium feeding from R1.

Ammonium Transformation in 14 Lakes along a Trophic Gradient

“…To analyze and discuss the experimental results, three parameters have been evaluated: (a) D25 and (b) D95, as time elapsed to observe an ammonium decrease of 25% and 95% of the initial concentration in amended microcosm; (c) OxRate, amount of ammonium oxidised in each day (µg NH 4 + /L day) to reduce the ammonium concentration from 25% to 95% of initial concentration in amended microcosms. To avoid redundancy among dependent variables, the relations between these parameters have been tested by Spearman's rank correlation coefficient.…”

“…In aquatic environments, total ammonia exists in two chemical forms, unionized ammonia (NH 3 ) and ionized ammonium (NH 4 + ) [7], with different percentage depending on pH. In general, in water at 8.0 pH and 20 • C, only about 10% of the total ammonia is present as the more toxic form, ammonia (NH 3 ).…”

“…Nitrogen pollution in water has become a serious global environmental problem. It causes water eutrophication, stimulating the growth of dinoflagellates and Cyanobacteria and influencing phytoplankton blooms, and represents a potential hazard to human health [3][4][5][6].…”

“…The water samples were collected in different months to highlight the possible effect of seasonality on the development of the ammonium oxidation process. In four-liter microcosms, concentrations were increased by 1 mg/L NH 4 + and the process of ammonium oxidation was constantly monitored. The time elapsed for the decrease of 25% and 95% of the initial ion ammonium concentration and the rate for that ammonium oxidation were evaluated.…”

Photocatalytic treatment of oil and grease spills in wastewater using coated N-doped TiO2 polyscales under sunlight as an alternative driving energy

“…Nowadays water treatment is expensive, and new technology is needed for the sustainable reclamation and reuse of polluted water and wastewater (Zekker et al 2012(Zekker et al , 2013(Zekker et al , 2015aRodrigo et al 2016;Ergo et al 2014;Sadler et al 1994). Due to drastic modernization and urbanizations, the use of petroleum oil and grease products for its energy need at industrial and anthropogenic activities has been increased drastically which led oil and grease pollution in water bodies (Hassan 1989;Rosario et al 2003;Agota et al 2012;Olumide et al 2011;Zekker et al 2012Zekker et al , 2014.…”