Search results for "DNRA"
showing 7 items of 7 documents
Denitrification and dissimilatory nitrate reduction to ammonium in a lake receiving wastewater effluent
2015
Denitrifikaatio ja DNRA (dissimilatory nitrate reduction to ammonium) ovat nitraattia pelkistäviä prosesseja, jotka yleensä esiintyvät hapettomissa olosuhteissa, kuten järvien sedimenteissä ja alusvesissä. Denitrifikaatiossa syntyy typpikaasua, joka poistuu ilmakehään, kun taas DNRA:n lopputuote on ammonium, joka jää veteen. Luonnollinen denitrifikaatio voi poistaa typpeä jätevedenpuhdistamon poistovedestä, mutta DNRA:n rooli on vähemmän tunnettu. Näiden prosessien tutkiminen voi auttaa jätevedenpuhdistuksen kehittämisessä. Tässä Pro Gradu –työssä tutkittiin denitrifikaation ja DNRA:n prosessinopeuksia sekä nopeuksien korrelaatioita erilaisten vedenlaatumuuttujien kanssa. Tutkimuspaikkana o…
Sediment diffusion method improves wastewater nitrogen removal in the receiving lake sediments
2018
Sediment microbes have a great potential to transform reactive N to harmless N2, thus decreasing wastewater nitrogen load into aquatic ecosystems. Here, we examined if spatial allocation of the wastewater discharge by a specially constructed sediment diffuser pipe system enhanced the microbial nitrate reduction processes. Full-scale experiments were set on two Finnish lake sites, Keuruu and Petäjävesi, and effects on the nitrate removal processes were studied using the stable isotope pairing technique. All nitrate reduction rates followed nitrate concentrations, being highest at the wastewater-influenced sampling points. Complete denitrification with N2 as an end-product was the main nitrat…
"Table 22" of "K^0_S and {\Lambda} production in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV"
2016
Total integrated mid-rapidity yields for K0Short in the rapidity range -0.5
"Table 23" of "K^0_S and {\Lambda} production in Pb-Pb collisions at sqrt(sNN) = 2.76 TeV"
2016
Total integrated mid-rapidity yields for LAMBDA in the rapidity range -0.5
Effets simultanés de niveaux croissants de glucose et de pressions partielles en oxygène sur la dénitrification et la réduction dissimilative du nitr…
1998
International audience; Dissimilatory nitrate reduction to ammonium (DNRA) and its importance in comparison to denitrification were studied in soil samples artificially repacked to control water potential and porosity, and incubated for 72 h. Labelled nitrate (100 mg N.kg-’ dry soil, 21.8 % 15N in excess) and increasing levels of glucose-C (250, 500 and 1 000 mg glucose-Ckg-’ dry soil) were initially added to the soil samples to obtain increasing glucose-C/nitrate-N ratios of 2.5,5 and 10, which were then subjected to different 0, partial pressures (0,0.5, 1.0 and 2.0 % (v/v)). The results confirmed the good reproducibility of the experimental condi- tions using this method. Denitrification…
Nitrate removal microbiology in woodchip bioreactors : a case-study with full-scale bioreactors treating aquaculture effluents
2020
Woodchip bioreactors are viable low-cost nitrate (NO3−) removal applications for treating agricultural and aquaculture discharges. The active microbial biofilms growing on woodchips are conducting nitrogen (N) removal, reducing NO3− while oxidizing the carbon (C) from woodchips. However, bioreactor age, and changes in the operating conditions or in the microbial community might affect the NO3− removal as well as potentially promote nitrous oxide (N2O) production through either incomplete denitrification or dissimilatory NO3− reduction to ammonium (DNRA). Here, we combined stable isotope approach, amplicon sequencing, and captured metagenomics for studying the potential NO3− removal rates, a…
Autochthonous organic matter promotes DNRA and suppresses N2O production in sediments of the coastal Baltic Sea
2021
Coastal environments are nitrogen (N) removal hot spots, which regulate the amount of land-derived N reaching the open sea. However, mixing between freshwater and seawater creates gradients of inorganic N and bioavailable organic matter, which affect N cycling. In this study, we compare nitrate reduction processes between estuary and offshore archipelago environments in the coastal Baltic Sea. Denitrification rates were similar in both environments, despite lower nitrate and carbon concentrations in the offshore archipelago. However, DNRA (dissimilatory nitrate reduction to ammonium) rates were higher at the offshore archipelago stations, with a higher proportion of autochthonous carbon. Th…