1209 - Co-occurrence of aerobic, anaerobic ammonia oxidation and nitrite oxidation in oxic riverbeds and their relationship with net nitrification efficiency

Abstract. The general features of the N cycle in the sunlit ocean are known, but quantitative information about multiple transformation rates among nitrogen pools, i.e., ammonium (NH4+), nitrite (NO2−), nitrate (NO3−) and particulate/dissolved organic nitrogen (PN/DON), are limited due to methodological difficulties. By adding a single 15N-labelled NH4+ tracer into incubators, we monitor ed the changes in concentration and isotopic composition of the total dissolved nitrogen (TDN), PN, NH4+, NO2−, and NO3− pools to trace the 15N and 14N flows. Based on mass conservation and isotope mass balance, we formulate d a matrix equation that allow edus to simultaneously derive the rates of multiple transformation processes in the nitrogen reaction web . We abandoned inhibitors and minimized the alteration of the system by adding a limited amount of tracer. In one single incubation, solution of the matrix equation provided the rates of NH4+, NO2−, and NO3− uptake; ammonia oxidation; nitrite oxidation; nitrite excretion; DON release; and potentially, the remineralization rate. To our knowledge, this is the first and most convenient method designed to quantitatively and simultaneously resolve complicated nitrogen transformation rates, albeit with some uncertainties. Field examples are given, and c omparisons with conventional labeling methods are discussed.

Download Full-text

Straw amendment to paddy soil stimulates denitrification but biochar amendment promotes anaerobic ammonia oxidation

Journal of Soils and Sediments ◽

10.1007/s11368-017-1694-4 ◽

2017 ◽

Vol 17 (10) ◽

pp. 2428-2437 ◽

Cited By ~ 12

Author(s):

Fuxia Pan ◽

Stephen James Chapman ◽

Yaying Li ◽

Huaiying Yao

Keyword(s):

Paddy Soil ◽

Ammonia Oxidation ◽

Anaerobic Ammonia Oxidation ◽

Straw Amendment ◽

Biochar Amendment

Download Full-text

Temporal variation in maximum cell-specific nitrification rate

Water Science & Technology ◽

10.2166/wst.2010.978 ◽

2010 ◽

Vol 61 (8) ◽

pp. 2069-2073 ◽

Cited By ~ 6

Author(s):

M. Fujita ◽

K. Tsuji ◽

A. Akashi

Keyword(s):

Ammonia Oxidation ◽

Thermal Power ◽

Nitrification Rate ◽

Nitrite Oxidation ◽

Cell Numbers ◽

Oxidation Rates ◽

Batch Tests ◽

Nitrogen Loads ◽

Clone Analysis ◽

Maximum Cell

The cell numbers of ammonia-oxidising bacteria (AOBs), Nitrospira and Nitrobacter in activated sludge used to treat wastewater from a thermal power plant in Japan were examined for nine months using a real-time PCR quantification technique. AOB cell numbers ranged 2.8 × 1010–2.3 × 1011 cell/L. The amoA clone analysis showed that the only Nitrosomonas halophila was responsible for ammonia oxidation over the period. Nitrospira were in the range of 2.6 × 109–2.4 × 1010 cell/L and Nitrobacter were less than 1% as common as Nitrospira. Meanwhile, maximum nitrification rates, maximum ammonia- and nitrite-oxidation rates obtained from aerobic batch tests, ranged 0.5–1.3 mmol-N/L h and 1.0–2.5 mmol-N/L h, respectively. No clear correlations were observed between the cell numbers of AOBs or Nitrospira and their maximum rates, because the maximum cell-specific ammonia- and nitrite-oxidation rates varied remarkably over the ranges of 1.1–11.9 and 2.4–21.6 fmol-N/cell h, respectively. To explore the factors controlling maximum cell-specific nitrification rates, the relationship to influent nitrogen loads per AOB or Nitrospira cell numbers was investigated. Fairly good correlations were obtained. Considering the effluent ammonia and nitrite concentrations were zero and only Nitrosomonas halophila had a role in ammonia oxidation over the period, we conclude that the amount of nitrogen oxidised per AOB or Nitrospira cell numbers likely controls maximum cell-specific ammonia- or nitrite-oxidation rates, respectively.

Download Full-text